morphological changes in polyvinyl butyral (pvb) electrospun nanofibres can be acquired by preparation of pvb spinning solution in different solvents.  accordingly, three solvents, including ethyl alcohol, n-butanol and isopropanol, with diverse physical properties (e.g. boiling point, density, dipole moment and dielectric constant) were used to prepare polyvinyl butyral (pvb) spinning solution...

6.1. Goal The objective of the work described in this chapter was to determine if the adsorption of a hydrogen-bonding homopolymer on SiO2 could be enhanced by thermal manipulation of solvent quality above or near the cloud point. It was shown in Chapter 2 from the studies of Killman and Malmsten that insolubility alone will not drive polymer adsorption, when the polymer is well solvated. Howev...

We demonstrate utilization of star-shaped polymers as high-density polymer brush coatings and their effectiveness to inhibit the adhesion of platelets and bacteria. Star polymers consisting of poly(2-hydroxyethyl methacrylate) (PHEMA) and/or poly(methyl methacrylate) (PMMA), were synthesized using living radical polymerization with a ruthenium catalyst. The polymer coatings were prepared by sim...

We formulate a coarse-grained molecular-dynamics model of polymer chains in solution that includes hydrodynamic interactions, thermal fluctuations, nonlinear elasticity, and topology-preserving solvent mediated excluded volume interactions. The latter involve a combination of potential forces with explicit geometric detection and tracking of chain entanglements. By solving this model with numer...

An amphiphilic silk-like protein polymer was efficiently produced in the yeast Pichia pastoris. The secreted product was fully intact and was purified by solubilization in formic acid and subsequent precipitation of denatured host proteins upon dilution with water. In aqueous alkaline solution, the negatively charged acidic polymer assumed extended helical (silk III-like) and unordered conforma...

High-voltage electrical fields and low production rate limit electrospinning, the electrical charging of polymer liquids, as a means of nanofiber fabrication. Here, we show a facile method of fabrication of aligned three-dimensional nanofiber structures by utilizing high-speed, rotating polymer solution jets to extrude fibers. Termed rotary jet-spinning, fiber morphology, diameter, and web poro...

We perform hybrid molecular dynamics simulations to study the flow behavior of rigid colloids dispersed in a dilute polymer solution. The underlying Newtonian solvent and the ensuing hydrodynamic interactions are incorporated through multiparticle collision dynamics, while the constituent polymers are modeled as bead-spring chains, maintaining a description consistent with the colloidal nature ...

An alkali-hydrolysable surfactant, (1-tetradecyloxycarbonylmethyl)trimethylammonium chloride, was used as an emulsifier for emulsion polymerization of styrene in water. The polymerization yielded a high molecular-weight polymer almost quantitatively. Addition of a small amount of NaOH to the resulting latex solution precipitated the polymer immediately. Analysis of the centrifuged solid indicat...

The combination of two self-assembly processes on different length scales leads to the formation of hierarchically structured nanoparticle arrays. Here, the formation of spherical cavities, or 'breath figures'-made by the condensation of micrometre-sized water droplets on the surface of a polymer solution-that self-assemble into a well-ordered hexagonal array, is combined with the self-assembly...

The removal of Reactive Black 5 dye in an aqueous solution by electrocoagulation (EC) as well as addition of flocculant was investigated. The effect of operational parameters, i.e. current density, treatment time, solution conductivity and polymer dosage, was investigated. Two models, namely the artificial neural network (ANN) and the response surface method (RSM), were used to model the effect...