The mechanisms that control the photophysics of composite films made of a semiconducting conjugated polymer (poly(paraphenylene vinylene), PPV) mixed with single-walled carbon nanotubes (SWNT) up to a concentration of 64 wt % are determined by using photoexcitation techniques and density functional theory. Charge separation is confirmed experimentally by rapid quenching of PPV photoluminescence...

We demonstrate a variable optical attenuator (VOA) at lambda=1.55 microm using a sheared polymer network liquid crystal (SPNLC). The SPNLC exhibits a fast response time and weak wavelength dependency. Comparing with other polymer-stabilized liquid crystals, the SPNLC has lower driving voltage and negligible light scattering loss when the wavelength exceeds 700 nm. A reflection type VOA with ~0....

By using soluble fullerene derivative [60]PCBM, we improved photorefractive efficiency in polymer-liquid crystal composites in comparison to previous works on similar materials. We show the effect of polymer network results in resolution and bandwidth improvements compared to pure liquid crystals. This is explained by the introduction of a charge trapping mechanism, providing a memory effect fo...

An array of polymer grid triodes connected by a common grid functions as a "plastic retina," providing local contrast gain control for image enhancement. This simple device, made from layers of conducting polymers, functions as an active resistive network that performs center-surround filtering. The polymer grid triode array with common grid is a continuous analog of the discrete approach of Me...

A new concept for formation of nanostructured intrinsically conducting polymers (ICP) is demonstrated. Polypyrrole can be electropolymerized from an ionic-surfactant-solution in TiO(2) nanotube framework to form a geometrical structure of self-organized nanopore arrays. Polymerization is initialized selectively in the space between nanotube walls forming a mechanically stable polymer network wi...

Strain-stiffening behavior common to biopolymer networks is difficult to reproduce in synthetic networks. Physically associating synthetic polymer networks can be an exception to this rule and can demonstrate strain-stiffening behavior at relatively low values of strain. Here, the stiffening behavior of model elastic networks of physically associating triblock copolymers is characterized by she...

We develop a hydrodynamic theory of active permeating gels with viscoelasticity in which a polymer network is embedded in a background fluid. This situation is motivated by active processes in the cell cytoskeleton in which motor molecules generate elastic stresses in the network, which can drive permeation flows of the cytosol. Our approach differs from earlier ones by considering the elastic ...

We have designed a unique strategy to obtain a zinc-salen functionalized porous polymer (Zn@SBMMP) with high zinc content (15.3 wt%) by an easy one-step, cost effective and scalable process, which shows unprecedented catalytic efficiency in the CO2 fixation reaction via cycloaddition of CO2 with epoxides. We hypothesize that a high density of Zn-Schiff base/salen units present in the porous pol...

In the title coordination polymer, [Cu(C(9)H(8)NO(4))(2)](n), the Cu atom, located on a twofold rotation axis, is four coordinate in a distorted square-planar environment. Each 2,6-dimethyl-pyridinium-3,5-dicarboxyl-ate anion bridges two Cu atoms, forming a two-dimensional coordination polymer. A three-dimensional supra-molecular network is built from N-H⋯O hydrogen bonds involving the pyridini...

The diffusion process through an ideal polymer network is studied by applying the effective medium theory (EMT) to a lattice-gas model. Polymers are modeled by random walks on the lattice bonds, across which molecules can hop with a certain probability. The steady state current of the system is calculated using the EMT and the results are compared to the simulations. Effective medium theory of ...