1
|
Song Y, Jiang R, Wang Z, Yin Y, Li B, Shi AC. Formation and Regulation of Multicompartment Vesicles from Cyclic Diblock Copolymer Solutions: A Simulation Study. ACS OMEGA 2020; 5:9366-9376. [PMID: 32363288 PMCID: PMC7191859 DOI: 10.1021/acsomega.0c00374] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 04/07/2020] [Indexed: 06/11/2023]
Abstract
The self-assembly of a cyclic AB copolymer system with relatively long A blocks and short B blocks in B-selective solvents is investigated using a simulated annealing method. By investigating the effect of the lengths and solubilities of A and B blocks (N A and N B, εAS and εBS), the incompatibility between A and B blocks (εAB), as well as the polymer concentration (C p) and the conditions for the formation of multicompartment vesicles in cyclic diblock copolymer solutions, is predicted. The phase diagrams in terms of N B, εAS, and C p are constructed. The mechanism of the morphological transition is elucidated. It is shown that for cyclic copolymers the change in the above factors relating to the polymer and solvent properties all can lead to the transition from simple vesicles to multicompartment vesicles, but two different transition mechanisms are revealed. In addition, our simulations demonstrate that the self-assembly of cyclic copolymers could provide a powerful strategy for regulating the compartment number and the wall thickness of the multicompartment vesicles by adjusting the block solubilities and block lengths, respectively. These findings will facilitate the application of multicompartment architectures in cell mimicry, drug delivery, and nanoreactors.
Collapse
Affiliation(s)
- Yongbing Song
- School
of Physics, Nankai University, Tianjin 300071, China
| | - Run Jiang
- School
of Physics, Nankai University, Tianjin 300071, China
| | - Zheng Wang
- School
of Physics, Nankai University, Tianjin 300071, China
| | - Yuhua Yin
- School
of Physics, Nankai University, Tianjin 300071, China
| | - Baohui Li
- School
of Physics, Nankai University, Tianjin 300071, China
| | - An-Chang Shi
- Department
of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| |
Collapse
|
2
|
Song Y, Xie T, Jiang R, Wang Z, Yin Y, Li B, Shi AC. Effect of Chain Architecture on Self-Assembled Aggregates from Cyclic AB Diblock and Linear ABA Triblock Copolymers in Solution. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:4013-4023. [PMID: 29544246 DOI: 10.1021/acs.langmuir.8b00630] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The self-assembly behaviors of two block copolymers with the same chain length but different chain architectures (cyclic AB, linear ABA) in B-selective solvents are investigated using Monte Carlo simulations. A morphological transition sequence, from spherical micelles to cylindrical micelles, to vesicles and then to multicompartment vesicles, is observed for both copolymer systems when the interaction between the solvophobic A-block and the solvent is increased. In particular, toroidal micelles could be formed in triblock systems due to the presence of the bridging chains at the parameter region between cylindrical micelles and vesicles whereas disklike micelles are formed in cyclic systems. The simulation results demonstrated that the architecture of block copolymers could be used to regulate the structural characteristics and thermal stability of these self-assembled aggregates.
Collapse
Affiliation(s)
- Yongbing Song
- School of Physics , Nankai University , Tianjin 300071 , China
| | - Teng Xie
- School of Physics , Nankai University , Tianjin 300071 , China
| | - Run Jiang
- School of Physics , Nankai University , Tianjin 300071 , China
| | - Zheng Wang
- School of Physics , Nankai University , Tianjin 300071 , China
| | - Yuhua Yin
- School of Physics , Nankai University , Tianjin 300071 , China
| | - Baohui Li
- School of Physics , Nankai University , Tianjin 300071 , China
| | - An-Chang Shi
- Department of Physics and Astronomy , McMaster University , Hamilton , Ontario L8S 4M1 , Canada
| |
Collapse
|
3
|
|
4
|
Song Y, Jiang R, Wang Z, Wang L, Yin Y, Li B, Shi AC. Topological Effect on the Structure of Self-Assembled Aggregates from Amphiphilic Macromolecules in Solution. MACROMOL THEOR SIMUL 2016. [DOI: 10.1002/mats.201600039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Yongbing Song
- School of Physics; Nankai University; Tianjin 300071 China
| | - Run Jiang
- School of Physics; Nankai University; Tianjin 300071 China
| | - Zheng Wang
- School of Physics; Nankai University; Tianjin 300071 China
| | - Lang Wang
- School of Physics; Nankai University; Tianjin 300071 China
| | - Yuhua Yin
- School of Physics; Nankai University; Tianjin 300071 China
| | - Baohui Li
- School of Physics; Nankai University; Tianjin 300071 China
| | - An-Chang Shi
- Department of Physics and Astronomy; McMaster University; Hamilton Ontario L8S 4M1 Canada
| |
Collapse
|
5
|
Ratcliffe LPD, McKenzie BE, Le Bouëdec GMD, Williams CN, Brown SL, Armes SP. Polymerization-Induced Self-Assembly of All-Acrylic Diblock Copolymers via RAFT Dispersion Polymerization in Alkanes. Macromolecules 2015. [DOI: 10.1021/acs.macromol.5b02119] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Liam P. D. Ratcliffe
- Dainton
Building, Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - Beulah E. McKenzie
- Dainton
Building, Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - Gaëlle M. D. Le Bouëdec
- Dainton
Building, Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| | - Clive N. Williams
- Scott Bader Company
Ltd., Wollaston, Wellingborough, Northants NN29 7RL, U.K
| | - Steven L. Brown
- Scott Bader Company
Ltd., Wollaston, Wellingborough, Northants NN29 7RL, U.K
| | - Steven P. Armes
- Dainton
Building, Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield, South Yorkshire S3 7HF, U.K
| |
Collapse
|
6
|
Abstract
This review describes the self-assembly of polymers with a cyclic topology and highlights how cyclization affects the resulting assemblies.
Collapse
|
7
|
Baba E, Honda S, Yamamoto T, Tezuka Y. ATRP–RCMpolymercyclization: synthesis of amphiphilic cyclic polystyrene-b-poly(ethylene oxide) copolymers. Polym Chem 2012. [DOI: 10.1039/c1py00475a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
8
|
Lee CU, Smart TP, Guo L, Epps TH, Zhang D. Synthesis and Characterization of Amphiphilic Cyclic Diblock Copolypeptoids from N-Heterocyclic Carbene-Mediated Zwitterionic Polymerization of N-Substituted N-carboxyanhydride. Macromolecules 2011; 44:9574-9585. [PMID: 22247571 PMCID: PMC3255090 DOI: 10.1021/ma2020936] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
N-Heterocyclic carbene (NHC)-mediated ring-opening polymerization of N-decylN-carboxylanhydride monomer (De-NCA) has been shown to occur in a controlled manner, yielding cyclic poly(N-decyl-glycine)s (c-PNDGs) with polymer molecular weights (MW) between 4.8 and 31 kg·mol(-1) and narrow molecular weight distributions (PDI < 1.15). The reaction exhibits pseudo-first order kinetics with respect to monomer concentration. The polymer MW increases linearly with conversion, consistent with a living polymerization. ESI MS and SEC analysesconfirm the cyclic architectures of the forming polymers. DSC and WAXS studies reveal that the c-PNDG homopolymers are highly crystalline with two prominent first order transitions at 72-79°C (T(m,1)) and 166-177°C (T(m,2)), which have been attributed to the side chain and main chain melting respectively. A series of amphiphilic cyclic diblock copolypeptoids [i.e.,poly(N-methyl-glycine)-b-poly(N-decyl-glycine) (c-PNMG-b-PNDG)] with variable molecular weight and composition was synthesized by sequential NHC-mediated polymerization of the corresponding N-methyl N-carboxyanhydride (Me-NCA) and De-NCA monomers. (1)H NMR analysis reveals that adjusting the initial monomer to NHC molar ratio can readily control the block copolymer chain length and composition. Time-lapsed light scattering and cryogenic transmission electron microscopy (cryo-TEM) analysis of c-PNDG-b-PNMG samples revealed that the amphiphilic cyclic block copolypeptoids self-assemble into spherical micelles that reorganize into micron-long cylindrical micelles with uniform diameter in room temperature methanol over the course of several days. An identical morphological transition has also been noted for the linear analogs, which occurs more rapidly than for the cyclic copolypeptoids. We tentatively attribute this difference to the different crystallization kinetics of the solvophobic block (i.e., PNDG) in the cyclic and linear block copolypeptoids.
Collapse
Affiliation(s)
- Chang-Uk Lee
- Department of Chemistry and Macromolecular Studies Group, Louisiana State University, Baton Rouge, LA 70803
| | - Thomas P. Smart
- Department of Chemical Engineering, University of Delaware, Newark, DE19716
| | - Li Guo
- Department of Chemistry and Macromolecular Studies Group, Louisiana State University, Baton Rouge, LA 70803
| | - Thomas H. Epps
- Department of Chemical Engineering, University of Delaware, Newark, DE19716
| | - Donghui Zhang
- Department of Chemistry and Macromolecular Studies Group, Louisiana State University, Baton Rouge, LA 70803
| |
Collapse
|
9
|
Lu J, Owen SC, Shoichet MS. Stability of Self-Assembled Polymeric Micelles in Serum. Macromolecules 2011; 44:6002-6008. [PMID: 21818161 PMCID: PMC3148800 DOI: 10.1021/ma200675w] [Citation(s) in RCA: 230] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 06/29/2011] [Indexed: 12/20/2022]
Abstract
The stability of polymeric nanoparticles in serum is critical to their use in drug delivery where dilution after intravenous injection often results in nanoparticle disassembly and drug unloading; however, few investigate this in biologically relevant media. To gain greater insight into nanoparticle stability in blood, the stability of self-assembled polymeric micelles of poly(d,l-lactide-co-2-methyl-2-carboxytrimethylene carbonate)-g-poly(ethylene glycol), P(LA-co-TMCC)-g-PEG, were tested in both serum and individual serum protein solutions. By encapsulating Förster resonance energy transfer pairs and following their release by fluorescence, these micelles demonstrated excellent thermodynamic and kinetic stability in the presence of serum. Further analyses by fast protein liquid chromatography and dynamic light scattering confirmed these data. Moreover, these micelles are compatible with red blood cells, as shown by a hemolysis assay. The stability and compatibility demonstrated in blood suggest that these micelles may be stable in vivo, which is critical for intravenous drug delivery applications. This comprehensive approach to understanding micelle stability and compatibility is broadly applicable.
Collapse
Affiliation(s)
- Jiao Lu
- Department of Chemistry, Department of Chemical Engineering and Applied Chemistry, and Institute of Biomaterials and Biomedical Engineering The Donnelly Centre, University of Toronto, Room 514, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Shawn C. Owen
- Department of Chemistry, Department of Chemical Engineering and Applied Chemistry, and Institute of Biomaterials and Biomedical Engineering The Donnelly Centre, University of Toronto, Room 514, 160 College Street, Toronto, ON M5S 3E1, Canada
| | - Molly S. Shoichet
- Department of Chemistry, Department of Chemical Engineering and Applied Chemistry, and Institute of Biomaterials and Biomedical Engineering The Donnelly Centre, University of Toronto, Room 514, 160 College Street, Toronto, ON M5S 3E1, Canada
| |
Collapse
|
10
|
Structures of the cylindrical and vesicular micelles of an P4VP-longer asymmetric PS-b-P4VP. Macromol Res 2009. [DOI: 10.1007/bf03218907] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
11
|
Rank A, Hauschild S, Förster S, Schubert R. Preparation of monodisperse block copolymer vesicles via a thermotropic cylinder-vesicle transition. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:1337-1344. [PMID: 19125559 DOI: 10.1021/la802709v] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In aqueous solution, poly(2-vinylpyridine-b-ethylene oxide) spontaneously forms bilayer vesicles, the size of which can be tailored by extrusion through polycarbonate membranes. However, their size can be even more precisely influenced by subjecting them to a specific cooling/warming process proceeding through a cylinder-vesicle shape transition. The thermotropic alterations of the polymer aggregates and the topological pathways of the cylinder-vesicle transition were followed by dynamic light scattering (DLS) and cryo-electron microscopy (cryo-TEM). Upon cooling the vesicles to 4degreesC, there is a transition of the vesicles to basketlike aggregates and their further disintegration to wormlike micelles. Rewarming of the dispersion results in the reformation of vesicles via intermediate discoid and octopus-like structures. The variation of incubation times at 4 and 25degreesC, heating rate, polymer concentration, and ionic strength allows tailored preparation of unilamellar and almost monodisperse vesicles with diameters between 60 and 500 nm. Furthermore, fluorescently labeled dextrans, which were used as model drugs of differing molar mass, could be easily and stably encapsulated during the thermotropic formation of vesicles from wormlike micelles.
Collapse
Affiliation(s)
- Anja Rank
- Department of Pharmaceutical Technology and Biopharmacy, Albert-Ludwigs-University Freiburg, D-79104 Freiburg, Germany
| | | | | | | |
Collapse
|
12
|
|
13
|
LaRue I, Adam M, Zhulina EB, Rubinstein M, Pitsikalis M, Hadjichristidis N, Ivanov DA, Gearba RI, Anokhin DV, Sheiko SS. Effect of the Soluble Block Size on Spherical Diblock Copolymer Micelles. Macromolecules 2008. [DOI: 10.1021/ma800403r] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Isaac LaRue
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Mireille Adam
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Ekaterina B. Zhulina
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Michael Rubinstein
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Marinos Pitsikalis
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Nikos Hadjichristidis
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Dimitri A. Ivanov
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Raluca I. Gearba
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Denis V. Anokhin
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| | - Sergei S. Sheiko
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290; Institute of Macromolecular Compounds of the Russian Academy of Sciences, 199004 St. Petersburg, Russia; Department of Chemistry, University of Athens, Panepistimiopolis, Zografou, 157 71 Athens, Greece; and Institut de Chimie des Surfaces et Interfaces, CNRS UPR 9069, 15 rue Jean Starcky, 68057 Mulhouse, France
| |
Collapse
|
14
|
Cui H, Hodgdon TK, Kaler EW, Abezgauz L, Danino D, Lubovsky M, Talmon Y, Pochan DJ. Elucidating the assembled structure of amphiphiles in solution via cryogenic transmission electron microscopy. SOFT MATTER 2007; 3:945-955. [PMID: 32900043 DOI: 10.1039/b704194b] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
For the past twenty years, significant progress has been made in both developing cryogenic transmission electron microscopy (cryo-TEM) technology and understanding assembled behavior of amphiphilic molecules. Cryo-TEM can provide high-resolution images of complex fluids in a near state. Samples embedded in a thin layer of vitrified solvent do not exhibit artifacts that would normally occur when using chemical fixation or staining-and-drying techniques. Cryo-TEM has been useful in imaging biological molecules in aqueous solutions. Cryo-TEM has become a powerful tool in the study of -assembled structures of amphiphiles in solution as a complementary tool to small-angle X-ray and neutron scattering, light scattering, rheology measurements, and nuclear magnetic resonance. The application of cryo-TEM in the study of assembled behavior of amphiphilic block copolymers, hydrogels, and other complex soft systems continues to emerge. In this context, the usage of cryo-TEM in the field of amphiphilic complex fluids and self-assembled nano-materials is briefly reviewed, and its unique role in exploring the nature of assembled structure in liquid suspension is highlighted.
Collapse
Affiliation(s)
- Honggang Cui
- Department of Materials Science and Engineering and Delaware Biotechnology Institute, University of Delaware, Newark, DE 19716.
| | - Travis K Hodgdon
- Center for Molecular Engineering and Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, DE 19716
| | - Eric W Kaler
- Center for Molecular Engineering and Thermodynamics, Department of Chemical Engineering, University of Delaware, Newark, DE 19716
| | - Ludmila Abezgauz
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Dganit Danino
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Maya Lubovsky
- Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Yeshayahu Talmon
- Department of Chemical Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Darrin J Pochan
- Department of Materials Science and Engineering and Delaware Biotechnology Institute, University of Delaware, Newark, DE 19716.
| |
Collapse
|
15
|
PbS nanoparticles/polymer composite aggregates through self-assembly of amphiphilic copolymer containing cross-linked hydrophilic block. Colloids Surf A Physicochem Eng Asp 2007. [DOI: 10.1016/j.colsurfa.2006.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
16
|
Bang J, Jain S, Li Z, Lodge TP, Pedersen JS, Kesselman E, Talmon Y. Sphere, Cylinder, and Vesicle Nanoaggregates in Poly(styrene-b-isoprene) Diblock Copolymer Solutions. Macromolecules 2006. [DOI: 10.1021/ma052023+] [Citation(s) in RCA: 188] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
17
|
|
18
|
Ouarti N, Viville P, Lazzaroni R, Minatti E, Schappacher M, Deffieux A, Putaux JL, Borsali R. Micellar aggregation in blends of linear and cyclic poly(styrene-b-isoprene) diblock copolymers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:9085-90. [PMID: 16171336 DOI: 10.1021/la050935z] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The morphology of micelles formed from blends of linear and cyclic poly(styrene-b-isoprene) (PS-b-PI) block copolymers has been investigated in solution using dynamic light scattering (DLS) and in thin solid deposits by atomic force microscopy (AFM) and transmission electron microscopy under cryogenic conditions (cryo-TEM). Micelles of the pure cyclic PS(290)-b-PI(110) copolymers are wormlike cylindrical objects built by unidirectional aggregation of 33 nm wide sunflower micelles, while the linear block copolymer having the same volume fraction and molar mass forms spherical micelles 40 nm in diameter. The DLS, AFM, and cryo-TEM results consistently show that the addition of the linear copolymer (even for amounts as low as 5% w/w) to the cyclic copolymer rather favors the formation of spherical micelles at the expense of the cylindrical aggregates. Those results clearly show that the linear block copolymer chains can be used to stabilize the thermodynamically unstable elementary sunflower micelle. The thermal stability of the micelles (from the pure copolymers and from the blends) has been examined in solid deposits with in situ AFM measurements. Coalescence starts at about 70 degrees C, and the surface roughness shows a two-step decrease toward a fully homogeneous and flat structure.
Collapse
Affiliation(s)
- Nadia Ouarti
- Service de Chimie des Matériaux Nouveaux, Université de Mons-Hainaut/Materia Nova, 20 Place du Parc, 7000 Mons, Belgium.
| | | | | | | | | | | | | | | |
Collapse
|