Two high bandgap benzodithiophene-benzotriazole-based polymers were synthesized via palladium-catalysed Stille coupling reaction. In order to compare the effect of the side chains on the opto-electronic and photovoltaic properties of the resulting polymers, the benzodithiophene monomers were substituted with either octylthienyl (PTzBDT-1) or dihexylthienyl (PTzBDT-2) as side groups, while the b...

Modification of deoxyguanosine at the C(8) position by the carcinogen N-acetoxy-N-2-acetylaminofluorene (N-AcO-AAF) has been shown to result in two different conformational changes dependent on the nucleotide sequence of the modified polymer. AAF modification of random sequence DNA results in a large distortion of the helix which is termed base displacement. In this conformation, the carcinogen...

A polymer chain pinned in space exerts a fluctuating force on the pin point in thermal equilibrium. The average of such fluctuating force is well understood from statistical mechanics as an entropic force, but little is known about the underlying force distribution. Here, we introduce two phase space sampling methods that can produce the equilibrium distribution of instantaneous forces exerted ...

Small-angle neutron scattering was used to investigate poly(N-isopropylacrylamide) (PNIPAM) polymer solutions in d-water/d-ethanol mixtures. A wide poor-solvent region was observed for mixtures near 60% d-water/40% dethanol mixture. Spinodal lines were determined, permitting a mapping of the mixing/demixing regions of the phase diagram which comprises two main branches: the left branch (with mo...

The hydrothermal synthesis, X-ray crystal structures and thermal and magnetic properties of a layered coordination polymer, [Ni(3.9)Mn(1.1)(μ(3)-OH)(2)(L(I))(2)(H(2)O)(10)]·2H(2)O (1) (L(I) = 1e,2a,4a,5e-cyclohexanetetracarboxylate), and a porous 3D coordination polymer, [Ni(4)(μ(2)-OH)(2)(μ(6)-H(2)L(IV))(2)(pymc)(4,4'-bpy)(H(2)O)(2)](OH)·9H(2)O (2) (pymc = 2-pyrimidinecarboxylate, 4,4'-bpy = 4...

Individual in situ polymerized fluorene chains 10-100 nm long linked by C-C bonds are pulled vertically from an Au(111) substrate by the tip of a low-temperature atomic force microscope. The conformation of the selected chains is imaged before and after manipulation using scanning tunneling microscopy. The measured force gradient shows strong and periodic variations that correspond to the step-...

The crystalline structure and molecular mobility of poly(vinylidene fluoride) (PVDF) blended with poly(methyl methacrylate) (PMMA) have been investigated using solid-state 19F magic angle spinning (MAS) NMR spectroscopy. The origin of the characteristic crystalline peaks observed for three typical polymorphs of PVDF (a-, band c-forms) are explained based on the density functional theory (DFT) c...

We present a study of the rheology and optical properties during the start-up of uniaxial extensional and shear flow for freely-draining, Kramers bead-rod chains using Brownian dynamics simulations. The viscous and elastic contributions to the polymer stress are unambiguously determined via methods developed in our previous publication [1]. The elastic contribution to the polymer stress is much...

– We propose new polymer models for Monte Carlo simulation and apply them to a polymer chain confined in a relatively thin box which has both curved and flat sides, and show that either an ideal or an excluded-volume chain spends more time in the curved region than in the flat region. The ratio of the probability of finding a chain in the curved region and in flat region increases exponentially...

Silane coupling agents have been frequently used as interfacial agents in polymer composites to improve interfacial strength and resistance to fluid migration. Although the capability of these agents in improving properties and performance of composites has been reported, there are still many uncertainties regarding the processing-structure-property relationships and the mechanisms of coupling ...