Download or read book Controlling Nanoparticle Location in Block Copolymers Using External Fields written by Vibha Kalra and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in materials synthesis and fabrication techniques allow an unprecedented control over the creation of novel building blocks such as polymers and particles. The first principle for effective utilization of these building blocks is to create techniques to control their assembly at length scales ranging from nanoscale to macroscopic scale. Hierarchically structured materials have been fabricated by combining the functionalities of block copolymer nanocomposites with the advantages of nanofibers. First, a novel methodology to synthesize block copolymer nanofibers with ordered self assembly has been developed, followed by a systematic study on how this self assembly is altered due to the cylindrical confinement of nanofibers. Then, this self assembly in nanofibers is used as a template to control the spatial distribution of functional nanoparticles. One of the key findings of this work is that a much larger fraction of nanoparticles can be placed (without agglomeration) within nanofibers compared to films of the same materials. To zero in on the mechanism and to understand the thermodynamic and kinetic processes that drive nanoparticle placement in block copolymers during deformation (an important constituent of electrospinning nanofiber fabrication process), coarse grained molecular dynamics simulations have been conducted. Here, the effect of shear flow on different types of block copolymer/nanoparticle systems has been first studied, followed by a study on effect of elongational flow on various block copolymer nanocomposite systems.

Download or read book Orientation and Morphology Control of Block Copolymers Using External Fields written by Youngwoo Choo and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Well aligned 3 dimensional Self assembly in Block Copolymers and Their Nanotechnological Applications written by Dae Up Ahn and published by . This book was released on 2007 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: "We have prepared well-aligned 3-dimensional block copolymer nano-cylinders over the entire sample area and thickness without any additional external field applications such as mechanical and electric fields. Self-assembled 3-dimensional perpendicular cylinder orientation was achieved by thermodynamic controls of incompatibility between the block components, and further elaborate modification of size and hexagonal alignment of perpendicular cylinders was also accomplished by kinetic controls of diffusive molecular mobility of block copolymer microdomains. Since those two controls have been mainly achieved by simple blending of minority homopolymer, the intrinsic advantages of block copolymer nanopatterning, such as fast and spontaneous 3-dimensional nanopatterning with a high thermodynamic stability and reproducibility, have been completely preserved in this fabrication strategy. After preparing block copolymer masks containing perpendicularly and hexagonally well-aligned nano-cylinders, a top-down method using excimer laser was applied to the block copolymer masks for a fast nanopattern transfer to organic and inorganic substrates in the form of nano-dots. Mask-image-like high-density polystyrene and silicon nano-dots were readily obtained after the one-step excimer laser irradiation on the block copolymer masks without any additional selective staining and/or etching steps before a non-selective etching process. The numerical analysis on the photothermal excimer laser ablation of periodically nanostructured block copolymer masks revealed that sufficiently low laser intensity was suitable for the one-step fabrication of mask image-like topographic nanopatterns on the surface of silicon substrates, as long as the intensity was high enough to induce a matrix-assisted photothermal excimer laser ablation in less UV-sensitive block component. Therefore, we illustrate a novel nanofabrication technique using a top-down after bottom-up method to create new opportunities for the fabrication of low-cost and high-throughput nanostructured materials with highly ordered 3-dimensional nanopatterns."--Abstract.

Download or read book Single Chain Polymer Nanoparticles written by José A. Pomposo and published by John Wiley & Sons. This book was released on 2017-08-18 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first book on this important and emerging topic presents an overview of the very latest results obtained in single-chain polymer nanoparticles obtained by folding synthetic single polymer chains, painting a complete picture from synthesis via characterization to everyday applications. The initial chapters describe the synthetics methods as well as the molecular simulation of these nanoparticles, while subsequent chapters discuss the analytical techniques that are applied to characterize them, including size and structural characterization as well as scattering techniques. The final chapters are then devoted to the practical applications in nanomedicine, sensing, catalysis and several other uses, concluding with a look at the future for such nanoparticles. Essential reading for polymer and materials scientists, materials engineers, biochemists as well as environmental chemists.

Download or read book Chemical Engineering Progress written by and published by . This book was released on 2008 with total page 718 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Block Copolymers in Nanoscience written by Massimo Lazzari and published by Wiley-VCH. This book was released on 2007-06-27 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: This first book to take a detailed look at one of the key focal points where nanotechnology and polymers meet provides both an introductory view for beginners as well as in-depth knowledge for specialists in the various research areas involved. It investigates all types of application for block copolymers: as tools for fabricating other nanomaterials, as structural components in hybrid materials and nanocomposites, and as functional materials. The multidisciplinary approach covers all stages from chemical synthesis and characterization, presenting applications from physics and chemistry to biology and medicine, such as micro- and nanolithography, membranes, optical labeling, drug delivery, as well as sensory and analytical uses.

Download or read book Block Copolymer Self assembly Fundamentals and Applications in Formulation of Nano structured Fluids written by Biswajit Sarkar and published by . This book was released on 2013 with total page 213 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dispersions of nanoparticles in polymer matrices form hybrid materials that can exhibit superior structural and functional properties and find applications in e. g. thermo-plastics, electronics, polymer electrolytes, catalysis, paint formulations, and drug delivery. Control over the particle location and orientation in the polymeric matrices are essential in order to realize the enhanced mechanical, electrical, and optical properties of the nanohybrids. Block copolymers, composed of two or more different monomers, are promising for controlling particle location and orientation because of their ability to organize into ordered nanostructures. Fundamental questions pertaining to nanoparticle-polymer interfacial interactions remain open and formulate the objectives of our investigation. Particle-polymer enthalpic and entropic interactions control the nanoparticle dispersion in polymer matrices. Synthetic chemical methods for modifying the particle surface in order to control polymer-particle interactions are involved and large scale production is not possible. In the current approach, a physical method is employed to control polymer-particle interactions. The use of commercially available solvents is found to be effective in modifying particle-polymer interfacial interactions. The approach is applicable to a wide range of particle-polymer systems and can thereby enable large scale processing of polymer nanohybrids. The systems of silica nanoparticles dispersed in long-range or short-range self-assembled structures of aqueous poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers (Pluronics) is considered here. The effect of various parameters such as the presence of organic solvents, pH, and particle size on the block copolymer organization and the ensuing particle-polymer interactions are investigated. Favorable surface interactions between the deprotonated silica nanoparticle and PEO-rich domain facilitate particle incorporation in the cylindrical lyotropic mesophase formed by hydrated PEO-PPO-PEO block copolymer. The amount of nanoparticle dispersed is limited to 10 wt% due to restrictions posed by a combination of thermodynamics and geometry. Incorporation of deprotonated nanoparticles by replacing equal mass of water did not affect the lattice parameter of the hexagonal lyotropic liquid crystalline structures formed by hydrated PEO-PPO-PEO block copolymer. The incorporation of protonated NPs resulted in an increase in the lattice parameter due to stronger nanoparticle-polymer enthalpic interactions. Two dimensional swelling exponent (d ~ Φpolymer-0. 65) suggests that deprotonated nanoparticles are located inside the PEO-rich domains, away from PEO-PPO interfaces. The presence of organic solvents screen the effect of protonated NPs on the lattice parameter of the hexagonal lyotropic liquid crystalline structures formed by hydrated PEO-PPO-PEO block copolymer.

Download or read book Mesoscale Modelling of Block Copolymers Under External Fields written by Kateryna Stanislavovna Lyakhova and published by . This book was released on 2005 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Points Lines and Walls written by Maurice Kléman and published by John Wiley & Sons. This book was released on 1983 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Self assembly of Block Copolymers in External Fields written by Alexander Böker and published by . This book was released on 2002 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Control of C60 POSS Nanoparticle Locaiton in Directed Self assembly of Block Copolymer Thin Films written by Jiajie Qian and published by . This book was released on 2014 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the advantage in self-assembly property of block copolymer (BCP), the nanoscale periodic patterns produced by the block copolymer have recently been identified as the next-generation precursor technique in many fields like nanolithographic templates, magnetic data storage, nanoporous membranes. The range of BCP periodicity is usually between 5nm and 100nm. By changing the molecular weight (N), volume fraction (f) of the components and segmental interaction, the anticipated results vary. These variations include BCP with lamellar, cylindrical, gyroid and spherical structures. Cylinder and lamella BCP are the invested especially popular, as their strong preferential interaction on the substrate results in the parallel or vertical orientation of micro domain. On the other hand, the material properties such as conductivity, hydrophilicity, mechanical and optical properties will be significantly affected depending on the way how nanoparticles (NPs) disperse within the polymer matrix. Therefore the ability to control the NPs arrangement is required. Although, a variety of methods have been explored to guide the NPs into the expected location, the ability to control positioning is still very limited, especially when the novel NPs are applied. The kinetics and intermolecular attraction are the generally accepted methods used to estimate the NPs location. In this study, location and dispersion of dumbbell-shaped fullerene (C60) bonding polyhedral oligomeric silsesquioxane (POSS) NPs were investigated on a variety of polystyrene (PS) and polymethylmethacrylate (PMMA) derivative polymer conditions. In the cases of homopolymers and polymer blends samples, the priority of C60-POSS NPs to PMMA phase was achieved due to the intermolecular forces. For the Z-direction distribution, enrichment areas of C60-POSS NPs were detected both on the top layer and bottom layer after the thin film samples were annealed due to the lower surface energy of C60-POSS NPs. Additionally, the exotic C60-POSS NPs would affect the PS-PMMA block copolymer self-assembly results involving both surface morphology and inner structure. More horizontal cylinders would form as the proportion of C60-POSS NPs was increased. In this study, Cold Zone Annealing-sharp was also used as a novel thermal annealing approach to explore the potential influences on the alignment of BCP/NPs nanocomposite.

Download or read book Encapsulation of Nanoparticles and Polymers Within Block Copolymer Micelles Prepared by the Emulsion and Solvent Evaporation Method written by Gauri M. Nabar and published by . This book was released on 2017 with total page 283 pages. Available in PDF, EPUB and Kindle. Book excerpt: Additives and external fields Surfactants used during micelle preparation had a surprising effect on the fluorescence of quantum dot loaded micelles. Surfactants that increased the density of the micelle coating around the encapsulated quantum dots enhanced their fluorescence and improved overall stability. External magnetic fields could impact the ordering of magnetic nanoparticles within micelles. This effect was even stronger when the external magnetic field was applied during the encapsulation of magnetic nanoparticles into micelles. Processing conditions Altering the solvent evaporation rate dramatically influenced micelle morphology. Very low rates of solvent evaporation yielded nanoparticle loaded block copolymer nanoparticles with intricate internal geometries. Our studies show that the emulsion and solvent evaporation process is a highly tunable and robust process that can afford access to micelles with interesting morphologies and superior functionality.

Download or read book Colloids in Drug Delivery written by Monzer Fanun and published by CRC Press. This book was released on 2016-04-19 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt: Colloidal drug delivery systems present a range of therapeutic benefits in the treatment of a number of challenging conditions, allowing researchers to cross barriers that have previously prevented efficient treatment while offering improved and more targeted absorption. Summarizing recent research in the field, Colloids in Drug Delivery assembles

Download or read book Orientation and Phase Behavior of Block Copolymers in External Electric Fields written by Kristin Schmidt and published by . This book was released on 2008-06-01 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Physics of Block Copolymers written by Ian W. Hamley and published by Oxford University Press on Demand. This book was released on 1998 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive and systematic text is the first of its kind to deal with the fundamental physics underlying the remarkable structural and dynamical properties of block copolymers. It provides the polymer scientist and technologist with a firm grounding in the principles underlying the wide applications of these important materials. It also highlights the intrinsically fascinating properties of block copolymers, such as nanoscale self-assembly in bulk and two-dimensions. The first textof its kind on the subject since the mid-1980s, this book stands alone - previous texts have focused on the chemical and material properties of block copolymers. During the last decade, there have been major developments in the field, and these experimental and theoretical advances are discussed in depth. Topics covered include: the thermodynamics and dynamics of block copolymer melts, block copolymers in dilute, semidilute and concentrated solutions, the structure of crystalline block copolymers and block copolymers in blends with other polymers. This informative book is essential to the polymer physics and materials science researcher in industry and academia, and postgraduates in related fields. Final year undergraduate students in chemistry, physics and materials science will also find this book useful as a reference text.

Download or read book Nanoparticle block Copolymer Self assembly written by Scott Charles Warren and published by . This book was released on 2007 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Directed Self Assembly of Polymer nanoparticle Composites Controlled by Internal and External Fields written by Christian Lewin and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: