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Biswas P, Sen D, Prasher M, Sarkar SK, Dasgupta K. Confinement driven anomalous freezing in nano porous spray dried microspheres. NANOTECHNOLOGY 2021; 32:385707. [PMID: 34116521 DOI: 10.1088/1361-6528/ac0ab6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 06/11/2021] [Indexed: 06/12/2023]
Abstract
One-step evaporative jamming of colloidal silica particles in contact-free spray droplets resulted in well-defined powder micro-granules with interstitial nanopores. This paper reports the anomalous freezing behaviour of confined water in the microspheres synthesized using spray drying. It has been revealed that the freezing point of water in these microspheres gets significantly lowered (∼-45 °C) owing to the confinement effect. Thermoporometry results are corroborated with the structural details obtained using complementary techniques of gas adsorption measurements and small-angle x-ray scattering.
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Affiliation(s)
- Priyanka Biswas
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, India
- Homi Bhabha National Institute, Mumbai-400094, India
| | - Debasis Sen
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, India
- Homi Bhabha National Institute, Mumbai-400094, India
| | - Meenu Prasher
- Materials Science Division, Bhabha Atomic Research Centre, Mumbai-400085, India
| | - Sudip Kumar Sarkar
- Materials Science Division, Bhabha Atomic Research Centre, Mumbai-400085, India
| | - Kinshuk Dasgupta
- Homi Bhabha National Institute, Mumbai-400094, India
- Glass and Advanced Materials Division, Materials Group, Bhabha Atomic Research Centre, Mumbai-400085, India
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2
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Biswas P, Sen D, Bouwman W. Structural characterization of spray-dried microgranules by spin-echo small-angle neutron scattering. POWDER TECHNOL 2021. [DOI: 10.1016/j.powtec.2020.10.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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3
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Neouze MA, Freitas AP, Ramamoorthy RK, Mohammedi R, Larquet E, Tusseau-Nenez S, Carrière D, Gacoin T. Toward a Chemical Control of Colloidal YVO 4 Nanoparticles Microstructure. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:9124-9131. [PMID: 32672970 DOI: 10.1021/acs.langmuir.0c01266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Rare-earth-doped oxides are a class of compounds that have been largely studied in the context of the development of luminescent nanocrystals for various applications including fluorescent labels for bioimaging, MRI contrast agents, luminescent nanocomposite coatings, etc. Elaboration of colloidal suspensions is usually achieved through coprecipitation. Particles exhibit emission properties that are similar to the bulk counterparts, although altered by crystalline defects or surface quenching species. Focusing on YVO4:Eu, one of the first reported systems, the aim of this work is to revisit the elaboration of nanoparticles obtained through a simple aqueous coprecipitation route. The objective is more precisely to get a better understanding of the parameters affecting the particles' internal microstructure, a feature that is poorly controlled and characterized. We show that the hydroxyl concentration in the precursor solution has a drastic effect on the particles' microstructure. Moreover, discrepancies in the reported particle structure are shown to possibly arise from the carbonation of the strongly basic orthovanadate precursor. For this study, SAXS/WAXS is shown to be a powerful tool to characterize the multiscale structure of the particles. It could be shown that playing on the precursor composition, it may be varied between almost monocrystalline nanocrystals to particles exhibiting a hierarchical microstructure well described by a surface fractal model. This work provides a new methodology for the characterization of nanoparticles microstructure and opens new directions for its optimization in view of applications.
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Affiliation(s)
- Marie-Alexandra Neouze
- Laboratoire de Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Université Paris-Saclay, Route de Saclay, 91128 Palaiseau Cedex, France
- Université Paris-Saclay, CEA, CNRS, NIMBE, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Alexy P Freitas
- Laboratoire de Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Université Paris-Saclay, Route de Saclay, 91128 Palaiseau Cedex, France
- Université Paris-Saclay, CEA, CNRS, NIMBE, CEA Saclay, 91191 Gif-sur-Yvette, France
| | | | - Rabei Mohammedi
- Laboratoire de Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Université Paris-Saclay, Route de Saclay, 91128 Palaiseau Cedex, France
| | - Eric Larquet
- Laboratoire de Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Université Paris-Saclay, Route de Saclay, 91128 Palaiseau Cedex, France
| | - Sandrine Tusseau-Nenez
- Laboratoire de Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Université Paris-Saclay, Route de Saclay, 91128 Palaiseau Cedex, France
| | - David Carrière
- Université Paris-Saclay, CEA, CNRS, NIMBE, CEA Saclay, 91191 Gif-sur-Yvette, France
| | - Thierry Gacoin
- Laboratoire de Physique de la Matière Condensée, Ecole Polytechnique, CNRS, Université Paris-Saclay, Route de Saclay, 91128 Palaiseau Cedex, France
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Ahlawat S, Sarkar SK, Sen D, Biswas A. Revisiting Temporal Evolution of Cu-Rich Precipitates in Fe-Cu Alloy: Correlative Small Angle Neutron Scattering and Atom-Probe Tomography Studies. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2019; 25:840-848. [PMID: 31046856 DOI: 10.1017/s1431927619000515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Binary Fe-Cu alloys are effective prototypes for investigating radiation-induced formation and growth of nanometric Cu-rich precipitates (CRPs) in nuclear reactor pressure vessels. In this report, the temporal evolution of CRPs during thermal aging of Fe-Cu binary alloys has been investigated by using complementary techniques such as atom probe tomography (APT) and small-angle neutron scattering (SANS). We report a detailed quantitative evolution of a rarely observed morphological transformation of Cu precipitates from spherical to ellipsoid with a significant change (approximately two times) in aspect ratio, an effect known to be associated with the 9R-3R structural transition of the precipitates. It is demonstrated through APT that the precipitates remain spherical up to 8 h, however, they subsequently convert to oblate ellipsoid upon further aging. SANS analysis also detected signs of this morphological transition in reciprocal space. Furthermore, SANS quantifies evolution of the precipitates and corroborates well with the APT results. Interestingly, the power-law exponent of the temporal evolution for mean size and number density agree reasonably well with the Lifshitz-Slyozov-Wagner model, in spite of the complex morphological evolution of the precipitates.
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Affiliation(s)
- Sarita Ahlawat
- Glass & Advanced Materials Division, Bhabha Atomic Research Centre,Mumbai-400085, Maharashtra,India
| | - Sudip Kumar Sarkar
- Glass & Advanced Materials Division, Bhabha Atomic Research Centre,Mumbai-400085, Maharashtra,India
| | - Debasis Sen
- Homi Bhabha National Institute,Mumbai-400094, Maharashtra,India
| | - Aniruddha Biswas
- Glass & Advanced Materials Division, Bhabha Atomic Research Centre,Mumbai-400085, Maharashtra,India
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Biswas P, Sen D, Mazumder S, Melo JS, Basak CB, Dasgupta K. Porous nano-structured micro-granules from silica-milk bi-colloidal suspension: Synthesis and characterization. Colloids Surf B Biointerfaces 2017; 154:421-428. [PMID: 28388528 DOI: 10.1016/j.colsurfb.2017.03.048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/28/2017] [Accepted: 03/23/2017] [Indexed: 02/06/2023]
Abstract
Synthesis and characterization of nano-structured porous granules, with fairly defined morphology and porosity, is crucial because such granules are widely utilized for various technological applications. However, an easy, one-step, economic synthesis protocol for large scale production is extremely desirable. In the present work, we have reported the synthesis and characterization of the nano-structured micro-granules using aerosol drying of bi-colloidal suspension of nano-silica and milk. Removal of soft organic component from the granules results in formation of meso and macro pores with moderate specific surface area. Granule morphology and porosity depends strongly on the concentration ratio of the individual components in the drying aerosol as well as the interaction between them.
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Affiliation(s)
- Priyanka Biswas
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India
| | - D Sen
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India.
| | - S Mazumder
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai, 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India
| | - J S Melo
- Nuclear Agriculture & Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai, 400094, India
| | - C B Basak
- Glass and Advanced Materials Division, Bhabha Atomic Research Centre, Mumbai, 400085, India
| | - Kinshuk Dasgupta
- Materials Group, Bhabha Atomic Research Centre, Mumbai, 400085, India
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Biswas P, Sen D, Mazumder S, Basak CB, Doshi P. Temperature Mediated Morphological Transition during Drying of Spray Colloidal Droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:2464-73. [PMID: 26900937 DOI: 10.1021/acs.langmuir.5b04171] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Understanding how a tiny dilute evaporative colloidal spray droplet gets transformed into a microgranule with a characteristic morphology is crucial from scientific as well as technological points of view. In the present work, it is demonstrated that the morphology and the size distribution of the microcapsules can be tuned simply by adjusting the drying temperature. Shape and size of the capsules are quantified at four different drying temperatures. It is shown that the morphology transits gradually from sphere to toroid with increasing temperature keeping the average volume-fraction of the correlated nanoparticles nearly unaffected for the synthesized granules. A plausible mechanism for the chronological pathway of such morphological transformation is illustrated. Computer simulation corroborates the experimentally observed morphological transition. The variation in hollowness and buckling tendency of the capsules are elucidated by scattering and imaging techniques.
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Affiliation(s)
| | - D Sen
- Homi Bhabha National Institute , Mumbai 400094, India
| | - S Mazumder
- Homi Bhabha National Institute , Mumbai 400094, India
| | | | - P Doshi
- Groton Laboratories, Pfizer Global Research and Development , Groton, 06340 Connecticut United States
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E. coli imprinted nano-structured silica micro-granules by spray drying: Optimization of calcination temperature. Colloids Surf B Biointerfaces 2015; 127:164-71. [DOI: 10.1016/j.colsurfb.2015.01.031] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 12/08/2014] [Accepted: 01/20/2015] [Indexed: 11/22/2022]
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8
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Das A, Sen D, Mazumder S, Ghosh AK, Basak CB, Dasgupta K. Formation of nano-structured core–shell micro-granules by evaporation induced assembly. RSC Adv 2015. [DOI: 10.1039/c5ra15650e] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Nano-structured spherical micro-granules of core–shell morphology have been realized by utilizing the contrasting interfacial interaction of two different types of nano-particles with liquid solvent.
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Affiliation(s)
- Avik Das
- Solid State Physics Division
- Bhabha Atomic Research Centre
- Mumbai – 400 085
- India
| | - D. Sen
- Solid State Physics Division
- Bhabha Atomic Research Centre
- Mumbai – 400 085
- India
| | - S. Mazumder
- Solid State Physics Division
- Bhabha Atomic Research Centre
- Mumbai – 400 085
- India
| | - A. K. Ghosh
- Membrane Development Section
- Chemical Engineering Group
- Bhabha Atomic Research Centre
- Mumbai – 400 085
- India
| | - C. B. Basak
- Glass and Advanced Materials Division
- Bhabha Atomic Research Centre
- Mumbai – 400 085
- India
| | - K. Dasgupta
- Rare Earths Development Section
- Materials Group
- Bhabha Atomic Research Centre
- Mumbai – 400 085
- India
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9
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Liu N, Pu X, Shi L. Direct syntheses of a promising industrial organic–inorganic hybrid silica containing methanesulphonate. Chem Eng Sci 2014. [DOI: 10.1016/j.ces.2014.06.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Sen D, Ghosh A, Mazumder S, Bindal R, Tewari P. Novel polysulfone–spray-dried silica composite membrane for water purification: Preparation, characterization and performance evaluation. Sep Purif Technol 2014. [DOI: 10.1016/j.seppur.2013.12.019] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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BAHADUR J, SEN D, MAZUMDER S, PAUL BHASKAR, KHAN ARSHAD. EVAPORATION DRIVEN SELF ASSEMBLY OF NANOPARTICLES DURING SPRAY DRYING: VOLUME FRACTION DEPENDENT PACKING. INTERNATIONAL JOURNAL OF NANOSCIENCE 2012. [DOI: 10.1142/s0219581x11008484] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Hierarchically structured micrometric mesoporous silica spheres have been synthesized by evaporation driven self assembly of silica colloids under slow drying condition. The inter particle correlation inside grains has been investigated by small-angle neutron scattering. In a slow drying regime, droplets shrink isotropically leading to spherical dried grains. However, the packing of nanoparticles depends on the initial colloidal concentration. The packing of the nanoparticles for low colloidal concentration is uniform throughout the grain but at higher concentration of the colloids, dried grains possess nonuniform radial packing of the nano-particles. The average packing fraction of the nanoparticles decreases with increasing colloidal concentration due to modification in viscosity of the colloidal dispersion prior to drying.
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Affiliation(s)
- J. BAHADUR
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - D. SEN
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - S. MAZUMDER
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - BHASKAR PAUL
- Materials Processing Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
| | - ARSHAD KHAN
- Materials Processing Division, Bhabha Atomic Research Centre, Mumbai 400085, India
- Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India
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Bahadur J, Sen D, Mazumder S, Paul B, Bhatt H, Singh SG. Control of buckling in colloidal droplets during evaporation-induced assembly of nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:1914-1923. [PMID: 22185181 DOI: 10.1021/la204161d] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Micrometric grains of anisotropic morphology have been achieved by evaporation-induced self-assembly of silica nanoparticles. The roles of polymer concentration and its molecular weight in controlling the buckling behavior of drying droplets during assembly have been investigated. Buckled doughnut grains have been observed in the case of only silica colloid. Such buckling of the drying droplet could be arrested by attaching poly(ethylene glycol) on the silica surface. The nature of buckling in the case of only silica as well as modified silica colloids has been explained in terms of theory of homogeneous elastic shell under capillary pressure. However, it has been observed that colloids, modified by polymer with relatively large molecular weight, gives rise to buckyball-type grains at higher concentration and could not be explained by the above theory. It has been demonstrated that the shell formed during drying of colloidal droplet in the presence of polymer becomes inhomogeneous due to the presence of soft polymer rich zones on the shell that act as buckling centers, resulting in buckyball-type grains.
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Affiliation(s)
- J Bahadur
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
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Berret JF. Controlling electrostatic co-assembly using ion-containing copolymers: from surfactants to nanoparticles. Adv Colloid Interface Sci 2011; 167:38-48. [PMID: 21376298 DOI: 10.1016/j.cis.2011.01.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2010] [Revised: 01/27/2011] [Accepted: 01/27/2011] [Indexed: 10/18/2022]
Abstract
In this review, we address the issue of the electrostatic complexation between charged-neutral diblock copolymers and oppositely charged nanocolloids. We show that nanocolloids such as surfactant micelles and iron oxide magnetic nanoparticles share similar properties when mixed with charged-neutral diblocks. Above a critical charge ratio, core-shell hierarchical structures form spontaneously under direct mixing conditions. The core-shell structures are identified by a combination of small-angle scattering techniques and transmission electron microscopy. The formation of multi-level objects is driven by the electrostatic attraction between opposite charges and by the release of the condensed counterions. Alternative mixing processes inspired from molecular biology are also described. The protocols applied here consist in screening the electrostatic interactions of the mixed dispersions, and then removing the salt progressively as an example by dialysis. With these techniques, the oppositely charged species are intimately mixed before they can interact, and their association is monitored by the desalting kinetics. As a result, sphere- and wire-like aggregates with remarkable superparamagnetic and stability properties are obtained. These findings are discussed in the light of a new paradigm which deals with the possibility to use inorganic nanoparticles as building blocks for the design and fabrication of supracolloidal assemblies with enhanced functionalities.
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Bahadur J, Sen D, Mazumder S, Bhattacharya S, Frielinghaus H, Goerigk G. Origin of buckling phenomenon during drying of micrometer-sized colloidal droplets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:8404-8414. [PMID: 21630693 DOI: 10.1021/la200827n] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The origin of the buckling of micrometer-sized colloidal droplets during evaporation-induced self-assembly (EISA) has been elucidated using electron microscopy and small-angle neutron scattering. Doughnut-like assembled grains with varying aspect ratios are formed during EISA at different physicochemical conditions. It has been revealed that this phenomenon is better explained by an existing hypothesis based on the formation of a viscoelastic shell of nanoparticles during drying than by other existing hypotheses based on the inertial instability of the initial droplets and hydrodynamic instability due to thermocapillary forces. This conclusion was further supported by the arrest of buckling through modification of the colloidal interaction in the initial dispersion.
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Affiliation(s)
- J Bahadur
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
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Lee SY, Gradon L, Janeczko S, Iskandar F, Okuyama K. Formation of highly ordered nanostructures by drying micrometer colloidal droplets. ACS NANO 2010; 4:4717-4724. [PMID: 20731450 DOI: 10.1021/nn101297c] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Nanoparticles with well-defined chemical compositions can act as building blocks for the construction of functional structures, such as highly ordered aggregates, as well as porous and hollow aggregates. In this work, a spray-drying technique is used to form a crystal-like structure with nanoparticle building blocks. When spray-drying uniform spherical particles, tightly packed aggregates with either simple or broken symmetries (quasicrystalline) were formed. Using polystyrene (PS) particles with varied zeta potentials as templates, it is also possible to form highly ordered porous and hollow aggregates from inorganic colloidal particles. Essential to the production of quasicrystalline structures is the use of monodisperse colloidal particles in spray drying, as the quasicrystalline form is not achievable when two different sizes of colloidal particles are used in the precursor suspension. With varying colloidal particles sizes, smaller colloidal particles fill the spaces formed between the larger particles, resulting in adjustment of colloidal crystallization. A geometric model that considers the tight packing of several spheres into frustrated clusters (quasicrystal form) with short-range icosahedral symmetry is compared to experimentally produced structures and found to quantitatively explain experimental observations.
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Affiliation(s)
- Sin Young Lee
- Department of Chemical Engineering, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima, Japan
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Bahadur J, Sen D, Mazumder S, Paul B, Khan A, Ghosh G. Evaporation-induced self assembly of nanoparticles in non-buckling regime: volume fraction dependent packing. J Colloid Interface Sci 2010; 351:357-64. [PMID: 20800848 DOI: 10.1016/j.jcis.2010.07.074] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 07/28/2010] [Accepted: 07/29/2010] [Indexed: 10/19/2022]
Abstract
Hierarchically structured micrometric spheres are synthesized by evaporation-induced self assembly of silica colloids using spray drying technique. Packing of nanoparticles during drying of droplets is an important issue. The motivation of the present work is to investigate the effects of concentration of initial colloidal dispersion on the packing of the nanoparticles in assembled grains in non-buckling regime of drying. It has been observed that the packing of nanoparticles inside the dried grains, even in the non-buckling regime, varies significantly with concentration. Although, the packing of nanoparticles remains uniform in an assembled grain at smaller concentration, the same becomes non-uniform at higher concentration. Further, the average packing fraction of the nanoparticles within the assembled grains, decreases with increasing colloidal concentration. These observations have been attributed to the modification in viscosity of the initial dispersion. Electron microscopy, light scattering measurements have been performed to probe overall morphology of the dried grains, while inter-particle correlation inside the grains has been investigated by small angle neutron scattering.
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Affiliation(s)
- J Bahadur
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
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17
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Sen D, Khan A, Bahadur J, Mazumder S, Sapra B. Use of small-angle neutron scattering to investigate modifications of internal structure in self-assembled grains of nanoparticles synthesized by spray drying. J Colloid Interface Sci 2010; 347:25-30. [DOI: 10.1016/j.jcis.2010.03.033] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 02/22/2010] [Accepted: 03/13/2010] [Indexed: 10/19/2022]
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18
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Sen D, Melo JS, Bahadur J, Mazumder S, Bhattacharya S, Ghosh G, Dutta D, D'Souza SF. Buckling-driven morphological transformation of droplets of a mixed colloidal suspension during evaporation-induced self-assembly by spray drying. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2010; 31:393-402. [PMID: 20480963 DOI: 10.1140/epje/i2010-10598-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Morphological transformation during evaporation-induced self-assembly of a mixed colloidal suspension in micrometric droplets has been investigated. It has been demonstrated that a buckling-driven shape transition of drying droplets of mixed colloidal suspension takes place during evaporation-induced self-assembly. Further, it is also shown that the distortion modulations get significantly amplified with enhancement in volume fraction of anisotropic soft colloidal component of the mixed colloids. It has been argued that the reduction in elastic modulus of formed shell, at the boundary of a drying droplet, and the anisotropic nature of one of the colloidal components facilitate the deformation process. Hierarchical structures of these assembled colloidal grains have been probed using electron microscopy and scattering techniques.
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Affiliation(s)
- D Sen
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai-400085, India.
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Fresnais J, Berret JF, Qi L, Chapel JP, Castaing JC, Sandre O, Frka-Petesic B, Perzynski R, Oberdisse J, Cousin F. Universal scattering behavior of coassembled nanoparticle-polymer clusters. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2008; 78:040401. [PMID: 18999367 DOI: 10.1103/physreve.78.040401] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2008] [Revised: 09/09/2008] [Indexed: 05/27/2023]
Abstract
Water-soluble clusters made from 7-nm inorganic nanoparticles have been investigated by small-angle neutron scattering. The internal structure factor of the clusters was derived and exhibited a universal behavior as evidenced by a correlation hole at intermediate wave vectors. Reverse Monte Carlo calculations were performed to adjust the data and provided an accurate description of the clusters in terms of interparticle distance and volume fraction. Additional parameters influencing the microstructure were also investigated, including the nature and thickness of the nanoparticle adlayer.
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Affiliation(s)
- J Fresnais
- Laboratoire Matière et Systèmes Complexes (MSC), UMR 7057 CNRS & Université Paris Diderot, Bâtiment Condorcet, 10 rue Alice Domon et Léonie Duquet, Paris, France
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