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Liao J, Wang W, Xu X, Jian H, Yang S. Interfacial Behavior of Giant Amphiphiles Composed of Azobenzene and Polyhedral Oligomeric Silsesquioxane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:1611-1620. [PMID: 35068145 DOI: 10.1021/acs.langmuir.1c03111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Giant amphiphiles containing azobenzene and polyhedral oligomeric silsesquioxane (POSS) units are synthesized by linking 4,4'-azodianiline (ADA) and POSS derivatives by stepwise amidation and further modification. The synthesized giant amphiphiles are photoresponsive and show trans-cis isomerization under ultraviolet (UV) irradiation. These giant amphiphiles are spread on the air-water interface and compressed by the barrier without and under UV irradiation. By compression, the giant amphiphiles undergo a phase transition from gas (G), liquid expanded (LE), liquid condensed (LC), and solid (S) to a final collapse on the water surface. The giant amphiphiles are cis-isomer-rich under UV irradiation and are trans-isomer-rich without UV irradiation. The trans-isomers are straight-shaped, while the cis-isomers are bent, and hence, their phase transition behaviors on the water surface exhibit a distinct difference.
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Affiliation(s)
- Jianwen Liao
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Weijie Wang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Xian Xu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Hanxin Jian
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
| | - Shuguang Yang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Center for Advanced Low-dimension Materials, College of Materials Science and Engineering, Donghua University, Shanghai 201620, P. R. China
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2
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Photodynamic control of bacterial motility by means of azobenzene molecules. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY 2021. [DOI: 10.1016/j.jpap.2021.100074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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3
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Ličen M, Masiero S, Pieraccini S, Drevenšek-Olenik I. Reversible Photoisomerization in Thin Surface Films from Azo-Functionalized Guanosine Derivatives. ACS OMEGA 2021; 6:15421-15430. [PMID: 34151120 PMCID: PMC8210406 DOI: 10.1021/acsomega.1c01879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 05/25/2021] [Indexed: 06/13/2023]
Abstract
Two novel azo-functionalized guanosine derivatives were synthesized, and their photoisomerization process was investigated in molecular monolayers at the air-water interface and in the Langmuir-Blodgett (LB) films on solid substrates. Measurements of surface pressure vs area isotherms, surface potential measurements, UV-visible (vis) absorption spectroscopy, Brewster angle microscopy (BAM), and atomic force microscopy (AFM) were performed. Despite not having a typical amphiphilic molecular structure, the derivatives formed stable films on the water surface. They could also undergo repeated photoisomerization in all of the investigated thin-film configurations. The observations suggest that in the films at the air-water interface, the molecules first exhibit a conformational change, and then they reorient to an energetically more favored orientation. In the LB films transferred onto solid substrates, the isomerization process occurs on a similar time scale as in solution. However, the isomerization efficiency is about an order of magnitude lower than that in solution. Our results show that DNA nucleobases functionalized with azobenzene moieties are suitable candidates for the fabrication of photoactive two-dimensional (2D) materials that can provide all beneficial functionalities of DNA-based compounds.
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Affiliation(s)
- Matjaž Ličen
- Faculty
of Mathematics and Physics, University of
Ljubljana, Jadranska 19, SI-1000 Ljubljana, Slovenia
| | - Stefano Masiero
- Dipartimento
di Chimica “Giacomo Ciamician”, Alma Mater Studiorum—Università di Bologna, Via San Giacomo 11, I-40126 Bologna, Italy
| | - Silvia Pieraccini
- Dipartimento
di Chimica “Giacomo Ciamician”, Alma Mater Studiorum—Università di Bologna, Via San Giacomo 11, I-40126 Bologna, Italy
| | - Irena Drevenšek-Olenik
- Faculty
of Mathematics and Physics, University of
Ljubljana, Jadranska 19, SI-1000 Ljubljana, Slovenia
- Department
of Complex Matter, Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
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4
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Kageyama Y, Ikegami T, Satonaga S, Obara K, Sato H, Takeda S. Light-Driven Flipping of Azobenzene Assemblies-Sparse Crystal Structures and Responsive Behaviour to Polarised Light. Chemistry 2020; 26:10759-10768. [PMID: 32190919 DOI: 10.1002/chem.202000701] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/12/2020] [Indexed: 12/30/2022]
Abstract
For creation of autonomous microrobots, which are able to move under conditions of a constant environment and a constant energy supply, a mechanism for maintenance of mechanical motion with a capacity for self-control is required. This requirement, known as self-organisation, represents the ability of a system to evade equilibrium through formation of a spatio-temporal pattern. Following our previous finding of a self-oscillatory flipping motion of an azobenzene-containing co-crystal, we present here regulation of the flipping motion by a light-receiving sensor molecule in relation to the alignment and role of azobenzene molecules in crystals. In the anisotropic structure, a specific azobenzene molecule acts as a reaction centre for the conversion of light to a mechanical function process, whereas the other molecules act as modulators for spatio-pattern regulation. The present results demonstrate that autonomously drivable molecular materials can exhibit information-responsive, self-sustainable motion by incorporating stimulus-responsive sensors.
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Affiliation(s)
- Yoshiyuki Kageyama
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Tomonori Ikegami
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, 060-0810, Japan
| | - Shinnosuke Satonaga
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, 060-0810, Japan
| | - Kazuma Obara
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, 060-0810, Japan
| | | | - Sadamu Takeda
- Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo, 060-0810, Japan
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Gao L, Hao Y, Zhang X, Huang X, Wang T, Hao H. Polymorph induced diversity of photomechanical motions of molecular crystals. CrystEngComm 2020. [DOI: 10.1039/d0ce00311e] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Photomechanical motions of the polymorphs of trans-4,4′-azopyridine are distinct under the influence of different molecular packing and intermolecular interactions.
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Affiliation(s)
- Lei Gao
- National Engineering Research Centre of Industrial Crystallization Technology
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin
- PR China
| | - Yunhui Hao
- National Engineering Research Centre of Industrial Crystallization Technology
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin
- PR China
| | - Xiunan Zhang
- National Engineering Research Centre of Industrial Crystallization Technology
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin
- PR China
| | - Xin Huang
- National Engineering Research Centre of Industrial Crystallization Technology
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin
- PR China
| | - Ting Wang
- National Engineering Research Centre of Industrial Crystallization Technology
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin
- PR China
| | - Hongxun Hao
- National Engineering Research Centre of Industrial Crystallization Technology
- School of Chemical Engineering and Technology
- Tianjin University
- Tianjin
- PR China
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6
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Ličen M, Masiero S, Drevenšek-Olenik I. Photoisomerizable Guanosine Derivative as a Probe for DNA Base-Pairing in Langmuir Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:6550-6561. [PMID: 31030520 PMCID: PMC6727594 DOI: 10.1021/acs.langmuir.9b00429] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/26/2019] [Indexed: 06/09/2023]
Abstract
Mixtures of azo-functionalized amphiphilic derivatives of guanosine and of amphiphilic derivatives of other DNA nucleobases were deposited at an air-water interface and repeatedly irradiated with light of 340 and 440 nm wavelengths. The consequent switching between cis and trans configurations of the azobenzene moiety caused changes in the surface pressure of the film, which were analyzed using a model based on the two-dimensional Van der Waals equation of state. For mixed films of guanosine and cytidine derivatives, the analysis revealed a significant modification of the strength of intermolecular interaction caused by the optical irradiation, while no such modifications were identified in mixed films involving other nucleobases. The difference is attributed to light-induced breaking of the hydrogen bonding that is established only between specific nucleobases. The results demonstrate that photosensitive nucleoside derivatives can be used as an efficient probe for base-pairing in Langmuir monolayers.
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Affiliation(s)
- M. Ličen
- Department
of Complex Matter, Jožef Stefan Institute, Jamova 39, SI 1000 Ljubljana, Slovenia
| | - S. Masiero
- Dipartimento
di Chimica “G. Ciamician”, Alma Mater Studiorum—Università di Bologna, Via San Giacomo 11, I-40126 Bologna, Italy
| | - I. Drevenšek-Olenik
- Department
of Complex Matter, Jožef Stefan Institute, Jamova 39, SI 1000 Ljubljana, Slovenia
- Faculty
of Mathematics and Physics, University of
Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
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7
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Del Pezzo R, Bandeira NA, Trojanowska A, Fernandez Prieto S, Underiner T, Giamberini M, Tylkowski B. Ortho-substituted azobenzene: shedding light on new benefits. PURE APPL CHEM 2018. [DOI: 10.1515/pac-2018-0719] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Novel functional polymeric microcapsules, based on modified azobenzene moieties, are exhaustively investigated, both from a theoretical and experimental points of view. Theoretical calculations and several measurements demonstrate that visible light can act as a trigger for release of encapsulated material, as a consequence of trans-cis isomerization which modifies microcapsule surface topography and can induce a “squeezing” release mechanism. Interfacial polymerization of an oil-in-water emulsion is performed and leads to core-shell microcapsules which are characterized by means of atomic force microscopy (AFM), optical microscopy (OM), scanning electron microscopy (SEM) and light scattering. These analyses put into evidence that microcapsules’ size and surface morphology are strongly affected by irradiation under visible light: moreover, these changes can be reverted by sample exposure to temperatures around 50°C. This last evidence is also confirmed by NMR kinetic analyses on modified azobenzene moiety. Finally, it is shown that these smart microcapsules can be successfully used to get a controlled release of actives such as fragrancies, as a consequence of visible light irradiation, as confirmed by an olfactive panel.
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Affiliation(s)
- Rita Del Pezzo
- Department of Chemical Engineering , Rovira i Virgili University , Av. Països Catalans 26 , Tarragona 43007 , Spain
- The Procter and Gamble Company , Temselaan 100 , Strombeek-Bever 1853 , Belgium
| | - Nuno A.G. Bandeira
- Biosystems and Integrative Sciences Institute, Faculty of Sciences , University of Lisbon , Campo Grande-C8 , Lisboa 1749-016 , Portugal
- Centro de Química Estrutural – Instituto Superior Técnico , Universidade de Lisboa , Av. Rovisco Pais , Lisboa 1049-001 , Portugal
- Institute of Chemical Research of Catalonia (ICIQ) – Avda. Països Catalans , Tarragona 16-43007 , Spain
| | - Anna Trojanowska
- Department of Chemical Engineering , Rovira i Virgili University , Av. Països Catalans 26 , Tarragona 43007 , Spain
- Centre Tecnològic de la Química de Catalunya , Carrer Marcelli Domingo s/n , Tarragona 43007 , Spain
| | | | - Todd Underiner
- The Procter and Gamble Company , 6210 Center Hill Avenue , Cincinnati, OH 45224 , USA
| | - Marta Giamberini
- Department of Chemical Engineering , Rovira i Virgili University , Av. Països Catalans 26 , Tarragona 43007 , Spain
- Centre Tecnològic de la Química de Catalunya , Carrer Marcelli Domingo s/n , Tarragona 43007 , Spain
| | - Bartosz Tylkowski
- Department of Chemical Engineering , Rovira i Virgili University , Av. Països Catalans 26 , Tarragona 43007 , Spain
- Centre Tecnològic de la Química de Catalunya , Carrer Marcelli Domingo s/n , Tarragona 43007 , Spain
- The Procter and Gamble Company , 6210 Center Hill Avenue , Cincinnati, OH 45224 , USA
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8
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Konidaris KF, Pilati T, Terraneo G, Politzer P, Murray JS, Scilabra P, Resnati G. Cyanine dyes: synergistic action of hydrogen, halogen and chalcogen bonds allows discrete I42− anions in crystals. NEW J CHEM 2018. [DOI: 10.1039/c8nj00421h] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Discrete tetraiodide dianions (I42−) are formed in crystals via halogen bond coordination of I2 by iodide anions which are pinned in their positions by a network of hydrogen bonds involving a benzoselenazole cyanine dye.
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Affiliation(s)
- Konstantis F. Konidaris
- Laboratory of Nanostructured Fluorinated Materials (NFMLab)
- Department of Chemistry
- Materials and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
| | - Tullio Pilati
- Laboratory of Nanostructured Fluorinated Materials (NFMLab)
- Department of Chemistry
- Materials and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
| | - Giancarlo Terraneo
- Laboratory of Nanostructured Fluorinated Materials (NFMLab)
- Department of Chemistry
- Materials and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
| | - Peter Politzer
- Department of Chemistry
- University of New Orleans
- New Orleans
- USA
| | - Jane S. Murray
- Department of Chemistry
- University of New Orleans
- New Orleans
- USA
| | - Patrick Scilabra
- Laboratory of Nanostructured Fluorinated Materials (NFMLab)
- Department of Chemistry
- Materials and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
| | - Giuseppe Resnati
- Laboratory of Nanostructured Fluorinated Materials (NFMLab)
- Department of Chemistry
- Materials and Chemical Engineering “Giulio Natta”
- Politecnico di Milano
- 20131 Milano
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9
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Cho EN, Zhitomirsky D, Han GGD, Liu Y, Grossman JC. Molecularly Engineered Azobenzene Derivatives for High Energy Density Solid-State Solar Thermal Fuels. ACS APPLIED MATERIALS & INTERFACES 2017; 9:8679-8687. [PMID: 28234453 DOI: 10.1021/acsami.6b15018] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Solar thermal fuels (STFs) harvest and store solar energy in a closed cycle system through conformational change of molecules and can release the energy in the form of heat on demand. With the aim of developing tunable and optimized STFs for solid-state applications, we designed three azobenzene derivatives functionalized with bulky aromatic groups (phenyl, biphenyl, and tert-butyl phenyl groups). In contrast to pristine azobenzene, which crystallizes and makes nonuniform films, the bulky azobenzene derivatives formed uniform amorphous films that can be charged and discharged with light and heat for many cycles. Thermal stability of the films, a critical metric for thermally triggerable STFs, was greatly increased by the bulky functionalization (up to 180 °C), and we were able to achieve record high energy density of 135 J/g for solid-state STFs, over a 30% improvement compared to previous solid-state reports. Furthermore, the chargeability in the solid state was improved, up to 80% charged from 40% charged in previous solid-state reports. Our results point toward molecular engineering as an effective method to increase energy storage in STFs, improve chargeability, and improve the thermal stability of the thin film.
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Affiliation(s)
- Eugene N Cho
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - David Zhitomirsky
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Grace G D Han
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Yun Liu
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Jeffrey C Grossman
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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10
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Ikegami T, Kageyama Y, Obara K, Takeda S. Dissipative and Autonomous Square-Wave Self-Oscillation of a Macroscopic Hybrid Self-Assembly under Continuous Light Irradiation. Angew Chem Int Ed Engl 2016; 55:8239-43. [DOI: 10.1002/anie.201600218] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 03/09/2016] [Indexed: 12/16/2022]
Affiliation(s)
- Tomonori Ikegami
- Graduate School of Chemical Sciences and Engineering; Hokkaido University; Sapporo 060-0810 Japan
| | - Yoshiyuki Kageyama
- Department of Chemistry; Faculty of Science; Hokkaido University; Sapporo 060-0810 Japan
- JST PRESTO; Kawaguchi 332-0012 Japan
| | - Kazuma Obara
- Department of Chemistry; Faculty of Science; Hokkaido University; Sapporo 060-0810 Japan
| | - Sadamu Takeda
- Department of Chemistry; Faculty of Science; Hokkaido University; Sapporo 060-0810 Japan
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11
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Ikegami T, Kageyama Y, Obara K, Takeda S. Dissipative and Autonomous Square-Wave Self-Oscillation of a Macroscopic Hybrid Self-Assembly under Continuous Light Irradiation. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201600218] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Tomonori Ikegami
- Graduate School of Chemical Sciences and Engineering; Hokkaido University; Sapporo 060-0810 Japan
| | - Yoshiyuki Kageyama
- Department of Chemistry; Faculty of Science; Hokkaido University; Sapporo 060-0810 Japan
- JST PRESTO; Kawaguchi 332-0012 Japan
| | - Kazuma Obara
- Department of Chemistry; Faculty of Science; Hokkaido University; Sapporo 060-0810 Japan
| | - Sadamu Takeda
- Department of Chemistry; Faculty of Science; Hokkaido University; Sapporo 060-0810 Japan
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12
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Photoisomerization of electroactive polyimide/multiwalled carbon nanotube composites on the effect of electrochemical sensing for ascorbic acid. POLYM INT 2014. [DOI: 10.1002/pi.4797] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Gupta M, Agarwal N, Arora A, Kumar S, Kumar B, Sheet G, Pal SK. Synthesis and characterization of novel azobenzene-based mesogens and their organization at the air–water and air–solid interfaces. RSC Adv 2014. [DOI: 10.1039/c4ra05572a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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14
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Yi Q, Sukhorukov GB. UV light stimulated encapsulation and release by polyelectrolyte microcapsules. Adv Colloid Interface Sci 2014; 207:280-9. [PMID: 24370006 DOI: 10.1016/j.cis.2013.11.009] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2013] [Revised: 11/05/2013] [Accepted: 11/14/2013] [Indexed: 12/18/2022]
Abstract
Layer-by-layer assembled polyelectrolyte capsules with well-controlled architectures and great versatility have been the subject of great interest, due to their unique advantages and tremendous potentials of being excellent candidates in multidisciplinary fields. UV light responsive microcapsules, as one class of the stimuli responsive capsules, possess the abilities to active their functionalities by responding to the UV stimulus remotely without requirement of direct contact or interaction. Therefore, any advances in this field will be of great value for the establishment of approaches to fabricate UV responsive polyelectrolyte capsules for desired uses. This review presents current development of UV responsive capsules, with emphasis on the underlying design strategies and their potential applications as delivery vesicles. In particular, UV-stimulated capsule functionalities, such as cargo encapsulation, release and combined multifunctionalities by the multilayers, have been addressed.
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15
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Yi Q, Sukhorukov GB. UV-induced disruption of microcapsules with azobenzene groups. SOFT MATTER 2014; 10:1384-1391. [PMID: 24651273 DOI: 10.1039/c3sm51648b] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
UV responsive microcapsules containing azobenzene were fabricated by sequential deposition of oppositely charged poly[1-[4-(3-carboxy-4-hydroxyphenylazo)benzenesulfonamido]-1,2-ethanediyl, sodium salt] (PAZO) and poly(diallyldimethyl ammonium) chloride (PDADMAC). As found in this work, combination of PDADMAC and PAZO led to aggregation of PAZO segments in the progress of polymer deposition, which facilitated the large extent of J aggregates when the capsules were exposed to UV light. J aggregate assemblies destroyed the integrity of capsule shell formations, demonstrating capsule swelling and further breakage. This UV induced capsule breakage offered a new way to modulate the release of encapsulated cargos.
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Affiliation(s)
- Qiangying Yi
- School of Engineering and Materials Science, Queen Mary, University of London, London, UK.
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16
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Yi Q, Sukhorukov GB. Externally triggered dual function of complex microcapsules. ACS NANO 2013; 7:8693-8705. [PMID: 24083649 DOI: 10.1021/nn4029772] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
By introducing UV-sensitive chemical groups causing different potential response as building blocks, fabricated LbL capsules can be endowed with dual UV-responsive properties in specific layers. One block is responsible for fast capsule sealing and the other for longer term capsule swelling and rupture. Therefore, the multifunction of these capsules could be activated selectively when exposed to external UV light with suitable wavelengths. In this work, dual-functional complex microcapsules (PDADMAC/PAZO)4-(DAR/Nafion)2 containing both diazonium and aozbenzene groups were proposed as clear examples to realize a time-dependent UV response for successive encapsulation and release. Upon exposure to UV light, the DAR/Nafion layers underwent a rapid in situ cross-linking and hence to seal the capsule shells through diazonium-related photolysis. Then further gradual shell swelling was followed by realignment of azobenzene molecules in PDADMAC/PAZO layers. Fluorescent polymers were consequently studied as cargo substances. Results indicated that continuous UV light triggered rapid cargo encapsulation over minutes time scale and gradual release with continuous irradiation over hours.
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Affiliation(s)
- Qiangying Yi
- School of Engineering and Materials Science, Queen Mary, University of London , Mile End Road, London, E1 4NS United Kingdom
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17
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Huang HY, Lee YT, Yeh LC, Jian JW, Huang TC, Liang HT, Yeh JM, Chou YC. Photoactively electroactive polyamide with azo group in the main chain via oxidative coupling polymerization. Polym Chem 2013. [DOI: 10.1039/c2py20374j] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Huang HY, Jian JW, Lee YT, Li YT, Huang TC, Chang JH, Yeh LC, Yeh JM. Effect of photoisomerization on the electroactivity and electrochromic behavior of aniline pentamer-based polymers with azo chromophore as reversibly switchable pendant group. POLYMER 2012. [DOI: 10.1016/j.polymer.2012.09.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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19
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Giner I, Haro M, Gascón I, Barrio JD, Carmen López M. Air–water interfacial behavior of linear-dendritic block copolymers containing PEG and azobenzene chromophores. J Colloid Interface Sci 2011; 359:389-98. [DOI: 10.1016/j.jcis.2011.03.091] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 03/24/2011] [Accepted: 03/26/2011] [Indexed: 11/30/2022]
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20
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Duan P, Qin L, Liu M. Langmuir-Blodgett films and chiroptical switch of an azobenzene-containing dendron regulated by the in situ host-guest reaction at the air/water interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1326-1331. [PMID: 21158398 DOI: 10.1021/la103934g] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
An amphiphilic dendron containing an azobenzene ring at the focal point and the l-glutamate peripheral groups was designed. Its monolayer formation and host-guest reaction with cyclodextrins at the air/water interface and the properties of the transferred Langmuir-Blodgett (LB) films were investigated. The individual dendron, although without any long alkyl chains, could still form a stable monolayer at the air/water interface because of the good balance between hydrophilic and hydrophobic parts within the molecule. When cyclodextrin (CyD) was added to the subphase, a host-guest reaction occurred in situ at the air/water interface. The inclusion of the focal azobenzene moiety into the cavity of cyclodextrin decreased the packing of the aromatic ring and also led to the diminishment of the molecular area. Both the films formed at the surface of pure water and aqueous cyclodextrins were transferred onto solid substrates. Nanofiber structures were obtained for the film from the water surface as a result of the packing of the azobenzene groups, and circular domains were obtained for the film transferred from the aqueous CyD phases. The film transferred from the water surface showed an exciton couplet in the absorption band of azobenzene, whereas a negative Cotton effect was obtained for the film from CyD subphases. It was found that the supramolecular chirality in the LB film transferred from water was due to the transfer of the molecular chirality to the assemblies whereas that from the CyD subphase was due to the inclusion of azobenzene into the chiral cavity. Interestingly, the film from the water surface was photoinactive, whereas a reversible optical and chiroptical switch could be obtained for the film from the α-CyD subphase. The work provided a way to regulate the assembly and functions of organized molecular films by taking advantage of the interfacial host-guest reaction.
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Affiliation(s)
- Pengfei Duan
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Colloid and Interface Science, Institute of Chemistry, CAS, Beijing, PR China
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Thermodynamics and mesoscopic organisation in Langmuir monolayers of an azobenzene derivative. J Colloid Interface Sci 2010; 352:449-55. [PMID: 20875643 DOI: 10.1016/j.jcis.2010.08.084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 08/30/2010] [Accepted: 08/31/2010] [Indexed: 11/21/2022]
Abstract
We have carried out the analysis of liquid crystalline Langmuir monolayers at the air-water interface composed of the amphiphilic azobenzene derivative 8Az5COOH. By varying the temperature and the isomeric (trans-cis) composition, the monolayer behaviour has been studied in comparison with a shorter homologue, 8Az3COOH, by measuring the surface pressure-area isotherms along with Brewster angle microscopy (BAM). Our data with the pure trans isomer enable a posterior thermodynamic analysis, which was not feasible with the shorter homologue. For the mixed trans-cis monolayers, BAM observations reveal a phase segregation with trans enriched domains surrounded by a cis enriched matrix. Line tension between the two phases is lower than in the shorter homologue. The organisation of the rodlike molecules inside the trans domains results in highly symmetric textures that make the quantitative analysis of the BAM images possible, and a better understanding of the microscopic structure of the monolayer can be achieved.
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Tylkowski B, Peris S, Giamberini M, Garcia-Valls R, Reina JA, Ronda JC. Light-induced switching of the wettability of novel asymmetrical poly(vinyl alcohol)-co-ethylene membranes blended with azobenzene polymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14821-14829. [PMID: 20799708 DOI: 10.1021/la101809r] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Novel composite asymmetrical membranes based on poly(vinyl alcohol)-co-ethylene (EVAL) as the host material and new polyethers that contain azobenzene moieties in the side chain were prepared by dry-cast phase inversion after dissolving the azo polymers in tetrahydrofuran and EVAL in dimethylsulfoxide and subsequently mixing the resulting solutions. By taking advantage of the proper temperature variation in the oven used for solvent evaporation, asymmetrical membranes that exhibited a dense, crystalline layer on the bottom and a porous, mainly amorphous layer on the top were obtained. Remarkable changes in the surface morphology and the contact angle with water were observed on the top surfaces of the composite membranes. This was ascribed not only to the enhanced concentration of azo polymer on the top surface but mostly to a conformational change in EVAL induced by the photoisomerization of the guest azo groups, as shown by HRMAS (1)H NMR. The morphological and structural changes in EVAL could be reversed on exposing the membrane to visible light for 24 h.
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Affiliation(s)
- Bartosz Tylkowski
- Departament d'Enginyeria Química, Universitat Rovira i Virgili, Av. Països Catalans, 26, E-43007 Tarragona, Spain
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STUDY ON THE LB FILMS OF A HAIRY-ROD LADDER POLYSILSESQUIOXANE WITH TRIPHENYLENE SIDE GROUPS. ACTA POLYM SIN 2009. [DOI: 10.3724/sp.j.1105.2009.00506] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Xu W, Wang Y, Xiao Y, Liu F, Lu GY. Langmuir monolayer and Langmuir-Blodgett films formed by a melamine-headed azobenzene-derived amphiphile: interfacial assembly affected by host-guest interaction. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:3646-3651. [PMID: 19708147 DOI: 10.1021/la8039708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A novel azobenzene-derived amphiphile with a melamine head, 2Azo-2C12H2-melamine, has been synthesized. pi-A isotherm measurements displayed that this amphiphile is able to form a stable Langmuir monolayer on both pure water and barbituric acid (BA)- or thymine (T)-containing subphases. The collapse surface pressure and limiting molecular area of its Langmuir monolayer on pure water are 40 mN/m and 0.56 nm2, respectively. However, when barbituric acid or thymine was introduced into the subphase, the corresponding pi-A isotherms of the monolayers exhibited a lower collapse surface pressure (22 mN/m for BA, 21 mN/m for T) and smaller limiting molecular area (0.54 nm2 for BA and 0.52 nm2 for T). UV-vis and FT-IR studies of the LB films formed by 2Azo-2C12H25-melamine have also been carried out. The results indicated that the LB films of 2Azo-2C12H25-melamine deposited from pure water undergo distinct collapse of the H-aggregate upon UV irradiation, while the LB films deposited from a BA- or T-containing subphase retain the H-aggregate. The host-guest-interaction-induced blockage of azobenzene photoisomerization should be responsible for the stabilized H-aggregate. A 1:1 host/guest binding mode to form a linear supramolecular polymeric chain has been proposed in the Langmuir monolayers formed on a BA- or T-containing subphase. The current results suggest that the host-guest interaction should be an effective means to manipulate the interfacial assembly of azobenzene-derived amphiphiles.
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Affiliation(s)
- Weihong Xu
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, People's Republic of China
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Niu L, Zhong C, Chen Z, Zhang Z, Li Z, Zhang F, Tang Y. Novel azobenzene-phthalocyanine dyads――design of photo-modulated J-aggregation. Sci Bull (Beijing) 2009. [DOI: 10.1007/s11434-009-0099-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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26
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Haro M, del Barrio J, Villares A, Oriol L, Cea P, López MC. Supramolecular architecture in Langmuir and Langmuir-Blodgett films incorporating a chiral azobenzene. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:10196-10203. [PMID: 18686982 DOI: 10.1021/la801299a] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
This article describes the synthesis and fabrication of Langmuir and Langmuir-Blodgett (LB) films incorporating a chiral azobenzene derivative, namely, ( S)-4- sec-butyloxy-4'-[5''-(methyloxycarbonyl)pentyl-1''-oxy]azobenzene, abbreviated as AZO-C4(S). Appropriate conditions for the fabrication of monolayers of AZO-C4(S) at the air-water interface have been established, and the resulting Langmuir films have been characterized by a combination of surface pressure and surface potential versus area per molecule isotherms, Brewster angle microscopy, and UV-vis reflection spectroscopy. The results indicate the formation of an ordered trilayer at the air-water interface with UV-vis reflection spectroscopy showing a new supramolecular architecture for multilayered films as well as the formation of J aggregates. Films were transferred onto solid substrates, with AFM revealing well-ordered multilayered films without 3D defects. Infrared and UV-vis absorption spectroscopy indicate that the supramolecular architecture may be favored by the formation of H bonds between acid groups in neighboring layers and pi-pi intermolecular interactions. Circular dichroism spectra reveal chiro-optical activity in multilayered LB films.
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Affiliation(s)
- Marta Haro
- Departamento de Quimica Organica-Quimica Fisica, Facultad de Ciencias, Universidad de Zaragoza, Plaza de San Francisco, Ciudad Universitaria, 50009 Zaragoza, Spain
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27
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Jiang M, Jiao T, Liu M. Photochromic Langmuir–Blodgett films based on polyoxomolybdate and gemini amphiphiles. NEW J CHEM 2008. [DOI: 10.1039/b716238c] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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29
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Seki T. Smart Photoresponsive Polymer Systems Organized in Two Dimensions. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.2084] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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30
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Shibata H, Sato M, Sakai H, Abe M, Matsumoto M. Direct Sol–Gel Fabrication of Patterned Zirconia Thin Films Using Self-assembly in Phase-separated Mixed Langmuir–Blodgett Films. CHEM LETT 2007. [DOI: 10.1246/cl.2007.1356] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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31
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Haro M, Gascón I, Aroca R, López MC, Royo FM. Structural characterization and properties of an azopolymer arranged in Langmuir and Langmuir-Blodgett films. J Colloid Interface Sci 2007; 319:277-86. [PMID: 17991483 DOI: 10.1016/j.jcis.2007.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2007] [Revised: 10/01/2007] [Accepted: 10/02/2007] [Indexed: 11/29/2022]
Abstract
The fabrication of Langmuir and Langmuir-Blodgett (LB) films of an acid-azopolymer (PAzCOOH) is reported. Several techniques were used in their characterization: surface pressure (pi) and surface potential (DeltaV) isotherms, UV-vis reflection spectroscopy, and Brewster angle microscopy (BAM) for the Langmuir films and contact angle measurements, UV-vis, fluorescence, IR and Raman spectroscopy and scanning electronic microscopy (SEM) for the LB films. Our study reveals that lateral chains of the polymer situate preferentially onto the water surface with the acid group in contact with the water, where aggregates are scarcely formed. Therefore, the lateral chains of PAzCOOH can be treated as individual monomers to determine structural properties of the fabricated Langmuir and LB films. Monomeric treatment has been used to interpret UV-vis reflection spectroscopy, and a monomer model has been performed to represent lateral chains using density functional theory at B3LYP 6-31G(d,p) level of theory to assign the observed vibrational spectra.
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Affiliation(s)
- Marta Haro
- Departamento de Química Orgánica-Química Física, Facultad de Ciencias, Universidad de Zaragoza, Plaza de San Francisco s/n, 50009 Zaragoza, Spain
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32
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Haro M, Giner B, Gascón I, Royo FM, López MC. Isomerization Behavior of an Azopolymer in Terms of the Langmuir−Blodgett Film Thickness and the Transference Surface Pressure. Macromolecules 2007. [DOI: 10.1021/ma0624752] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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33
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Haro M, Ross DJ, Oriol L, Gascón I, Cea P, López MC, Aroca RF. Spectroscopic characterization and Langmuir-Blodgett films of a novel azopolymer material. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:1804-9. [PMID: 17279659 DOI: 10.1021/la061491p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Spectroscopic characterization and fabrication of Langmuir and Langmuir-Blodgett (LB) films of an azopolymer-pyridine (PAzPy) are reported. UV-visible absorption and fluorescence spectra, Fourier transform infrared (FTIR) spectra, and Raman spectra were recorded. The vibrational assignment of the observed spectra is supported by a complete geometry optimization, followed by vibrational frequency and intensity computations of both the trans and cis forms of the monomer (AzPy) using density functional theory at the B3LYP 6-31G(d,p) level of theory. Langmuir monolayers of the polymer (PAzPy) were formed at the water-air interface, and LB films of high quality were formed onto solid substrates. The polymer LB films were investigated by surface-enhanced Raman scattering.
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Affiliation(s)
- Marta Haro
- Departamento de Química OrgAnica-Química Física, Facultad de Ciencias, Plaza de San Francisco, Ciudad Universitaria, 50009 Zaragoza, Spain
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Matsumoto M. Photoreactions and lateral patterning in Langmuir and Langmuir–Blodgett films. CHEM REC 2007; 7:69-77. [PMID: 17385729 DOI: 10.1002/tcr.20099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Reversible morphological changes occur with photoisomerization of azobenzene in Langmuir-Blodgett (LB) films complexed with polycations, which contradicts an implicit assumption of the concept of free volume that two-dimensional film structures are preserved during the photoisomerization. J-aggregates of chromophores are formed by two processes. The first process is "light-induced J-aggregation" in which photoisomerized molecules form J-aggregates. The other process is "triggered J-aggregation," in which photoisomerization of one of the components triggers J-aggregation of another chemical species in the mixed films. Both processes of J-aggregation are in many cases accompanied by large morphological changes of the films. However, LB films fabricated using processes under isobaric conditions do not change their morphology during light-induced J-aggregation and are patterned with J-aggregates using ultraviolet illumination through a photomask. Phase separation in mixed LB films gives rise to two-dimensional patterns, which are used to fabricate templates by using an amphiphilic silane-coupling agent as one of the components in the mixed LB films. Nanopatterns are also fabricated.
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Affiliation(s)
- Mutsuyoshi Matsumoto
- Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
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35
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Zhang Y, Chen P, Liu M. Supramolecular chirality from an achiral azobenzene derivative through the interfacial assembly: effect of the configuration of azobenzene unit. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:10246-50. [PMID: 17107028 DOI: 10.1021/la062427a] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The Langmuir-Schaefer (LS) films of an achiral azobenzene derivative, 4-octyl-4'-(5-carboxypentamethyleneoxy) azobenzene (C8AzoC5), were fabricated and their optical activities were investigated. It was found that the LS film of the trans-C8AzoC5 showed strong Cotton effect, while that of cis-C8AzoC5 did not. The characterization of the LS films by UV-vis, Fourier transform infrared (FT-IR) spectra, and X-ray diffraction (XRD) revealed that this interesting phenomenon was due to the different packing of the azobenzene unit in the LS film. The planar conjugated trans-azobenzene favored ordered cooperative packing in a helical sense and produced the supramolecular chirality, while the cis-isomer did not due to the bulky twisted configuration.
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Affiliation(s)
- Yiqun Zhang
- Beijing National Laboratory for Molecular Science, CAS Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, Chinese Academy of Sciences, 100080 Beijing, China
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36
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Fu ZS, Xue HL, Wang CQ, Liu MD, Yuan L. Relationship between the absorption spectra and spatial hindrance in starch graft copolymers. J Appl Polym Sci 2006. [DOI: 10.1002/app.21935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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37
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Shankar BV, Patnaik A. Surface pressure driven supramolecular architectures from mixed H-aggregates of dye-capped azobenzene derivative. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:4758-65. [PMID: 16649793 DOI: 10.1021/la053186u] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
We demonstrate a soft chemical approach for the synthesis of dimensionally dictated functionalized mesostructures by continuous tuning of the surface molecular density of a photoreceptable molecule (E)-1-(3-chloro-4-(octyloxy)phenyl)-2-phenyldiazene (compound 1) with Rhodamine B (Rh B). Highly oriented cylindrical microtubules with a hollow center running the entire distance of the assembly in a parallel-packed configuration were formed at the air-water interface. The surface tension driven self-organized structures were evidenced from electronic absorption and steady-state fluorescence spectroscopy in conjunction with optical, polarizing, and epifluorescence microscopy and microspectroscopy; the structural building blocks were identified to be mixed H-aggregates from compound 1 and Rh B of 1:1 stoichiometry, corroborated by a blue shift in the characteristic absorption features. The appearance of a crossover point (apparent isosbestic point) instead of a sharp defined isosbestic point in the absorption spectra signified the formation of mixed H-aggregates from trans-azobenzenes in ion-dipole interaction with the charged Rh B. Increasing the temperature induced an end-to-end self-assembly of the hollow tubules, and photoisomerization of compound 1 did not serve as a trigger to induce self-organization. A nonfluorescent planar crystalline morphology with irregular topology was observed for its isomer (E)-1-(4-chlorophenyl)-2-(4-(octyloxy)phenyl) diazene (compound 2).
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Affiliation(s)
- B Vijai Shankar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600 036, India
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Takahashi M, Okuhara T, Yokohari T, Kobayashi K. Effect of packing on orientation and cis–trans isomerization of azobenzene chromophore in Langmuir–Blodgett film. J Colloid Interface Sci 2006; 296:212-9. [PMID: 16185705 DOI: 10.1016/j.jcis.2005.09.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2005] [Revised: 07/12/2005] [Accepted: 09/04/2005] [Indexed: 11/20/2022]
Abstract
Photoactive film material of long-chain azobenzene derivative, p-(omega-trimethylammoniodecyloxy)-p'-octyloxyazobenzene bromide (TAOAB), was fabricated into a Langmuir-Blodgett (LB) film by a polyion-complex technique using poly(sodium 4-styrenesulfonate) as a polyanion. To investigate the effect of the packing state of the azobenzene chromophore on its orientation and cis-trans isomerization, TAOAB was mixed with methyl stearate in the LB film matrix at various mole fractions (X(TAOAB)), and structural characterizations were subsequently carried out by means of Fourier transform infrared and ultraviolet-visible spectroscopies, X-ray diffraction analysis, and atomic force microscopy. The results obtained show that as the degree of packing increases, both the azobenzene chromophores and the hydrocarbon chains orient more perpendicularly to the surface of the LB film. In addition, reversible cis-trans photoisomerization of TAOAB took place upon alternate irradiation with UV and visible light even in a mixed LB film with the chromophores in a dense lateral packing state. In the process of thermal cis-to-trans isomerization, we found that the reaction rate is strongly affected by the packing state of TAOAB at 20 degrees C, reflecting the differences in steric hindrance among LB films of various X(TAOAB). In addition, higher activation energy was obtained for thermal cis-to-trans isomerization when the free volume around the chromophores became smaller.
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Affiliation(s)
- Masashi Takahashi
- Department of Environmental Energy Engineering, Musashi Institute of Technology, 1-28-1 Tamazutsumi, Setagaya, Tokyo 158-8557, Japan.
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Ciminelli C, Granucci G, Persico M. Are azobenzenophanes rotation-restricted? J Chem Phys 2005; 123:174317. [PMID: 16375538 DOI: 10.1063/1.2098628] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We simulated the photoisomerization dynamics of an azobenzenophane with a semiclassical surface hopping approach and a semiempirical reparametrized quantum mechanics/molecular mechanics Hamiltonian. Only one of the two azobenzene chromophores in the molecule is taken into account quantum mechanically: the other one is treated by molecular mechanics. Both n-->pi* and pi-->pi* excitations are considered. Our results show that the photoisomerization reaction mainly involves the rotation around the N=N double bond. The excited state relaxation features are in qualitative agreement with experimental time-resolved fluorescence results.
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Affiliation(s)
- Cosimo Ciminelli
- Dipartimento di Chimica e Chimica Industriale, via Risorgimento 35, 56126 Pisa, Italy
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Nowak AM, McCreery RL. In Situ Raman Spectroscopy of Bias-Induced Structural Changes in Nitroazobenzene Molecular Electronic Junctions. J Am Chem Soc 2004; 126:16621-31. [PMID: 15600368 DOI: 10.1021/ja045763r] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Carbon/nitroazobenzene (NAB)/titanium/gold molecular electronic junctions with active thicknesses of 7-8 nm were constructed having partially transparent Ti/Au top contacts, which permitted in situ monitoring of molecular structure with Raman spectroscopy for applied biases between +3 and -3 V. Deposition of the Ti/Au top contacts resulted in spectral changes similar to those accompanying NAB reduction in a conventional spectroelectrochemical experiment. Upon application of +3 V (carbon relative to Ti), the spectrum indicated reoxidation of the NAB reduction product, and this redox cycle could be repeated at least three times. When a voltage excursion to -2 or -3 V occurred, the spectra indicated irreversible loss of the nitro group, and a dramatic but reversible decrease in Raman intensity over the entire shift range examined. Negative applied voltage causes formation of reduced NAB and a high oxidation state of titanium, while positive voltage forms oxidized NAB and injects electrons into the titanium oxide layer. The spectral changes were correlated with current/voltage curves in order to probe the mechanism of rectification and conductance switching reported previously. Overall, the combination of spectroscopic and voltammetric results implies a conduction mechanism involving both NAB and titanium oxide, possibly mediated by the injection of carriers into the semiconducting titanium oxide, or by reduction of an insulating titanium oxide to a more conductive form.
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Affiliation(s)
- Aletha M Nowak
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, USA
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Nakazawa T, Azumi R, Sakai H, Abe M, Matsumoto M. Control of photoreaction of amphiphilic spiropyran/n-alkane Langmuir and Langmuir-Blodgett films using the phase transition of n-alkane. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:10583-10590. [PMID: 15544388 DOI: 10.1021/la0482857] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The structures and photoreactions of Langmuir and Langmuir-Blodgett (LB) films of an amphiphilic spiropyran, 1',3'-dihydro-3',3'-dimethyl-6-nitro-1'-octadecyl-8-(docosanoyloxymethyl)spiro[2H-1-benzopyran-2,2'-(2H)-indole] (SP), mixed with n-alkane are investigated. The mixing ratio was fixed at 1/2 for SP/n-alkane. The surface pressure-area isotherms of SP/octadecane are categorized into two regimes: a low-temperature regime where octadecane is packed with the alkyl chains of SP, and a high-temperature regime where the addition of octadecane does not influence the isotherms significantly. The temperature dividing the two regimes is related with the melting point of the n-alkane mixed with SP in the bulk. UV irradiation of the Langmuir film in the high-temperature regime gives rise to light-induced J-aggregation, whereas that in the low-temperature regime causes only the isomerization of SP to the corresponding merocyanine, indicating that J-aggregation is hindered by the presence of n-alkane in the low-temperature regime. IR external reflection spectroscopy of the Langmuir films shows that n-alkane is released from the film during J-aggregation. The structural changes of the mixed Langmuir and LB films during J-aggregation are almost the same with those of the films of pure SP.
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Affiliation(s)
- Takahiro Nakazawa
- Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan
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Matsumoto M, Tanaka KI, Azumi R, Kondo Y, Yoshino N. Template-directed patterning using phase-separated Langmuir-Blodgett films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:8728-8734. [PMID: 15379499 DOI: 10.1021/la0488250] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The structures of the mixed Langmuir-Blodgett (LB) films of conventional amphiphiles (CAs) and amphiphilic silane-coupling agents (SCAs) were investigated using IR spectroscopy, atomic force microscopy, and friction force microscopy. By using CAs having hydrogenated alkyl chains and SCAs having perfluorinated alkyl chains, phase-separated structures were formed with domains consisting of CAs surrounded by SCAs. The size and shape of the domains depended strongly on the mixed components, the mixing ratios, and the subphase temperature. In particular, usage of a CA having hydrogenated and perfluorinated portions in the hydrophobic group as one of the components led to the formation of nanothreads. When the phase-separated mixed LB films were heated, SCAs formed covalent bonds with the substrates having silanol groups whereas CAs did not have such ability. Rinsing the heat-treated LB films with ethanol selectively removed CAs with the SCA regions intact, resulting in the fabrication of templates. The structures of the templates reflected those of the original phase-separated LB films. LB transfer of amphiphiles on the templates led to the confinement of the amphiphiles in regions with the size and shape delineated by the templates. These results demonstrate that a variety of amphiphiles can be confined two-dimensionally in a designed manner.
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Affiliation(s)
- Mutsuyoshi Matsumoto
- Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5-2, 1-1-1 Higashi, 305-8565, Japan.
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Nakazawa T, Azumi R, Sakai H, Abe M, Matsumoto M. Brewster angle microscopic observations of the Langmuir films of amphiphilic spiropyran during compression and under UV illumination. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:5439-44. [PMID: 15986684 DOI: 10.1021/la049582e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The structure of the Langmuir film of an amphiphilic spiropyran, 1',3'-dihydro-3',3'-dimethyl-6-nitro-l'-octadecyl-8-(docosanoyloxyme thyl)spiro[2H-1-benzopyran-2,2'-(2H)-indole] (SP), is investigated using Brewster angle microscopy (BAM). The BAM observations show that the Langmuir film of SP can be roughly categorized into three regimes: a low-temperature regime at 7-13 degrees C; a medium-temperature regime at 23-30 degrees C; a high-temperature regime at 40 degrees C. The low-temperature regime is characterized both by the domains that are formed just after the spreading and by the onset of the surface pressure when the domains are merged together to form continuous trilayers. In the medium-temperature regime, a continuous monolayer film is formed after the solvent evaporation, followed by the growth of "embryos" with compression. Around the phase transition point, the "embryos" serve as the "nucleation sites" of the circular trilayer domains. The characteristic features of the high-temperature regime are similar to the ones of the medium-temperature regime except for the absence of a steep rise in surface pressure after the plateau region and the absence of the circular trilayer domains. UV illumination of the Langmuir films leads to the isomerization of SP into merocyanine (MC). However, J-aggregates of MC are formed only when the circular trilayer domains are present. On the basis of the above results, we present a phase diagram of the Langmuir film of SP. The structure and photoreaction depend strongly on the phase of the Langmuir film, indicating that the area/molecule is not the only decisive parameter.
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Affiliation(s)
- Takahiro Nakazawa
- Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan
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Seki T. Dynamic Photoresponsive Functions in Organized Layer Systems Comprised of Azobenzene-containing Polymers. Polym J 2004. [DOI: 10.1295/polymj.36.435] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Nowak AM, McCreery RL. Characterization of Carbon/Nitroazobenzene/Titanium Molecular Electronic Junctions with Photoelectron and Raman Spectroscopy. Anal Chem 2004; 76:1089-97. [PMID: 14961743 DOI: 10.1021/ac034807w] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Molecular junctions consisting of nitroazobenzene (NAB) chemisorbed to a substrate of pyrolyzed photoresist film (PPF) and a top contact of vapor-deposited titanium were examined with Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The thickness of the NAB layer varied from submonolayer to 4.5 nm, and a thin (1-3 nm) overlayer of Ti was deposited by electron beam deposition. Without Ti, the NAB surface Raman spectrum was sufficiently strong to observe previously unreported modes in the 500-1000-cm(-1) region, and the 1000-1700-cm(-1) region was sufficiently strong to observe the effects of metal deposition. Upon Ti deposition, the intensities of NAB modes associated with the nitro group decreased significantly, and the XPS indicated formation of a Ti-N bond. For the thicker NAB layers (1.9 and 4.5 nm), the intensities of the NO(2) Raman modes partially recovered over a several-day period, but they remain depressed or absent in the submonolayer sample. The results indicate a reaction between condensing Ti atoms and the terminal NO(2) group, probably to form a Ti-nitroso linkage between NAB and Ti. The result is a molecular junction with covalent bonding at both ends in the form of a C-C bond between PPF and NAB and a Ti-N bond to the top contact. The structural implications of the current results are interpreted in the context of recently reported functioning PPF/NAB/Ti molecular electronic junctions. In particular, the reaction between Ti and the nitro group appears to prevent short circuits resulting from incursion of Ti into the NAB layer.
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Affiliation(s)
- Aletha M Nowak
- Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, OH 43210-1185, USA
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Yang G, Zeng Q, Wan L, Bai C. Structure of self-assembled monolayer of NPAN on Au(111) electrode. CHINESE SCIENCE BULLETIN 2003. [DOI: 10.1007/bf03183985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Weber R, Winter B, Hertel IV, Stiller B, Schrader S, Brehmer L, Koch N. Photoemission from Azobenzene Alkanethiol Self-Assembled Monolayers. J Phys Chem B 2003. [DOI: 10.1021/jp0226681] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | | | | | | | - N. Koch
- Institut für Physik, Physik von Makromolekülen, Humboldt-Universität zu Berlin, D-12489 Berlin, Germany
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Bujdák J, Iyi N, Fujita T. Isomerization of cationic azobenzene derivatives in dispersions and films of layered silicates. J Colloid Interface Sci 2003; 262:282-9. [PMID: 16256605 DOI: 10.1016/s0021-9797(03)00235-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2002] [Accepted: 02/27/2003] [Indexed: 11/28/2022]
Abstract
Photoisomerization reactions of cationic azobenzene dyes in solutions, dispersions, and films of layered silicates were studied by visible (Vis) spectroscopy. The dyes isomerized reversibly from thermodynamically more stable trans-isomers to cis-isomers when irradiated with ultraviolet (UV) light. Observed trends were compared with the optical changes of the dyes that occurred as a consequence of their adsorption at the silicate surface. Small fractions of the dyes are likely to have isomerized during the adsorption process, even without the UV-light irradiation. The aggregation of the dyes was another reaction taking place at the surface of the silicates. The extent of the UV-light-induced isomerization reactions was reduced for the adsorbed dye cations. The reaction proceeded readily for a dye with monovalent cations. However, the photoisomerization was practically negligible in both dispersions and films of layered silicates for a dye with bivalent cations, whereas the isomerization proceeded in solution. This phenomenon was interpreted in terms of the attractive electrostatic forces between the substrate and the dye cations, which hindered the isomerization reaction. The layer charge of silicates affected the orientation of the dye cations as observed by X-ray diffraction (XRD) measurements. However, the choice of silicate did not significantly affect the fundamental aspects and the described basic trends of the UV-light-induced isomerization reaction.
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Affiliation(s)
- Juraj Bujdák
- Institute of Inorganic Chemistry, Slovak Academy of Sciences (SAS), Bratislava SK-84536, Slovak Republic.
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Matsumoto M, Nakazawa T, Azumi R, Tachibana H, Yamanaka Y, Sakai H, Abe M. Light-Induced J-Aggregation of Merocyanine in Langmuir and Langmuir−Blodgett Films. J Phys Chem B 2002. [DOI: 10.1021/jp0214716] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mutsuyoshi Matsumoto
- Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5−2, Tsukuba 305-8565, Japan, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan, and Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 4, Tsukuba 305-8562, Japan
| | - Takahiro Nakazawa
- Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5−2, Tsukuba 305-8565, Japan, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan, and Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 4, Tsukuba 305-8562, Japan
| | - Reiko Azumi
- Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5−2, Tsukuba 305-8565, Japan, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan, and Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 4, Tsukuba 305-8562, Japan
| | - Hiroaki Tachibana
- Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5−2, Tsukuba 305-8565, Japan, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan, and Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 4, Tsukuba 305-8562, Japan
| | - Yasushi Yamanaka
- Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5−2, Tsukuba 305-8565, Japan, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan, and Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 4, Tsukuba 305-8562, Japan
| | - Hideki Sakai
- Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5−2, Tsukuba 305-8565, Japan, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan, and Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 4, Tsukuba 305-8562, Japan
| | - Masahiko Abe
- Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 5−2, Tsukuba 305-8565, Japan, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510, Japan, and Correlated Electron Research Center, National Institute of Advanced Industrial Science and Technology, AIST Tsukuba Central 4, Tsukuba 305-8562, Japan
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