In this paper, a multi-scale coupling mathematical model is suggested for simulating the polymer filling process in weld line region on micro scale. The considers two aspects: one based stresses whole cavity region; other of continuum mechanics (CM) and molecular dynamics (MD) weldline region. A weak variational formulation constructed finite element method (FEM), which coupled with Verlet algo...

A novel class of stereocomplexes is described by the interaction of helically complementary poly(phenylacetylene)s (PPAs) carrying an α-methoxy-α-trifluoromethylphenylacetamide pendant group. The formation of the stereocomplex requires the presence of cis amide bonds on the external crest of the polymer to provide efficient cooperative supramolecular hydrogen bonding between matching enantiomer...

Highly extensible Escherichia coli DNA molecules in planar extensional flow were visualized in dilute solution by fluorescence microscopy. For a narrow range of flow strengths, the molecules were found in either a coiled or highly extended conformation, depending on the deformation history of the polymer. This conformation hysteresis persists for many polymer relaxation times and is due to conf...

Confinement and surface effects provided by nanoparticles have been shown to produce changes in polymer molecules affecting their macroscopic viscosity. Nanoparticles may induce rearrangements in polymer conformation with an increase in free volume significantly lowering the viscosity. This phenomenon is generally attributed to the selective adsorption of the polymer high molar mass fraction on...

Solution and solid state two dimensional NMR are important tools for materials characterization, and for understanding the structure and dynamics of polymers. The power of NMR as a tool arises from its ability to visualize individual sites along the polymer main chain and side chain, making it possible to relate the structure and dynamics at the molecular level to the bulk macroscopic propertie...

Introduction The conformation of a polymer chain is very sensitive to changes in the surrounding environment. When polymer chains are chemically tethered at one end to a stiff solid substrate or interface with a sufficiently high grafting density, the chains avoid overlapping and stretch along the surface normal to form a polymer brush layer. Thus, substrates and interfaces can be modified with...

The role of sequential adsorption of a non-interacting pair of polymer (polyacrylic acidPAA) and surfactant (sodium dodecyl sulfate-SOS) on alumina particles and in determining the stability of their suspensions was studied with particular attention to the confonnation of the polymer. It was found that the sequence of addition is of critical importance in detennining the dispersion/flocculation...

Construction of predominantly one-handed helical polyacetylenes with a desired helix sense utilizing noncovalent chiral interactions with nonracemic chiral guest compounds based on a supramolecular approach is described. As with the conventional dynamic helical polymers possessing optically active pendant groups covalently bonded to the polymer chains, this noncovalent helicity induction system...

The isomers 4′-(4-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (1), 4′-(3-(trifluoromethyl)phenyl)-4,2′:6′,4″-terpyridine (2), 4′-(4-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (3), and 4′-(3-(trifluoromethyl)phenyl)-3,2′:6′,3″-terpyridine (4) have been prepared characterized. single crystal structures of 1 2 were determined. 1D-polymers [Cu2(hfacac)4(1)2]n·2nC6H4Cl2 (Hhfacac = 1,1,1,5,5...

We investigate the chain conformation of ring polymers confined to a cylindrical nanochannel using both theoretical analysis and three-dimensional Langevin dynamics simulations. We predict that the longitudinal size of a ring polymer scales with the chain length and the diameter of the channel in the same manner as that for linear chains based on scaling analysis and Flory-type theory. Moreover...