Chemically responsive polymers are macromolecules that respond to local variations of the chemical composition solution by changing their conformation, with notable examples including polyelectrolytes, proteins, and DNA. The polymer conformation changes can occur in response pH, ionic strength, or concentration a generic solute interacts polymer. These stimuli lead drastic flexibility even trig...

In the primary walls of growing plant cells, the glucose polymer cellulose is assembled into long microfibrils a few nanometers in diameter. The rigidity and orientation of these microfibrils control cell expansion; therefore, cellulose synthesis is a key factor in the growth and morphogenesis of plants. Celery (Apium graveolens) collenchyma is a useful model system for the study of primary wal...

The adsorption of polydisperse ideal polymer chains is shown to be sensitive to the large N tail of the distribution of chains. If and only if the number of chains decays more slowly than exponentially then there is an adsorption transition like that of monodisperse infinite chains. If the number decays exponentially the adsorption density diverges continuously at a temperature which is a funct...

Polymer fiber drawing creates fibers with enhanced thermal conductivity and strength compared to bulk polymer because drawing aligns the molecular chains. I optimize the polymer fiber drawing method in order to achieve polymer fibers that are drawn to lengths exceeding 1cm and develop a method to cut and store them for future experimental purposes. With lengths exceeding 1cm, starting with leng...

We have investigated conformational properties of a linear semiflexible homopolymer chain in the bulk and adsorption desorption behaviour in the presence of an attractive impenetrable curved surface using lattice models. Since, it is understood that the essential physics associated with the conformational behavior of such polymer chains can be derived from a model of a self avoiding walk (SAW) ...

The presence of polymer chains grafted or adsorbed onto a surface can dramatically alter the forces that affect interactions between surfaces. The equilibrium properties of such polymer brush systems have been studied for the past two decades, yielding general agreement between theory and experiment. Conversely, the nonequilibrium properties of polymer brushes are still under intense theoretica...

We have studied the high-frequency (34 GHz) mobility of positive charge carriers on isolated ladder-type polymer chains in dilute solution. We find that the high-frequency mobility is limited by the chain ends on chains as long as 35 monomers. The intrachain motion of charge carriers can be described by one-dimensional diffusion between infinitely high reflecting barriers, representing the chai...

Up to this point we have considered polymer chains in solvent at various concentrations. In dilute solution, we observed that the segmental density is localized around the center of mass of the coils; the local concentration gradient experienced by each chain drives the swelling of the coils. By contrast, in polymer melts, this swelling force is exactly cancelled by analogous forces exerted by ...

A brief review is given of some of the advances in hydrodynamic methodologies for studying the conformation and flexibility of biomacromolecules in mixed systems. We consider first of all evaluation of conformation type and flexibility in polymer systems with a quasi-continuous distribution of molecular weight – using polysaccharides and mucin glycoproteins as our main examples, and then confor...

In the title compound, C16H22N2O, the azepan-2-one ring adopts a chair conformation, while the 1,2,3,4-tetra-hydro-pyridine ring adopts a half-chair conformation. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds, forming supra-molecular chains propagated along [10-1], with weak C-H⋯O inter-actions occurring between the chains.