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Molecular imaging elucidating the arrangements in arrays, orientations and even intramolecular structures using Scanning tunneling microscopy (STM) has been achieved not only in ultrahigh vacuum (UHV) but also solutions. Construction and in-space visualization of supramolecular adlayers (adsorbed layers) on well-defined single crystal surfaces have received significant attention in the last decade. Coupling supramolecular chemistry and scanning probe microscopy (SPM) allows the visual consideration of molecular self-assembly in sub-molecular space.
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A bicontinuous microemulsion (BME, Winsor III), also called a middle-phase microemulsion, is a low-viscosity, isotropic, thermodynamically stable, spontaneously formed solution phase composed of water, organic solvent, and surfactants. The dynamic morphology of a microemulsion (ME) is generally determined by the hydrophilicity–lipophilicity balance (HLB) of the surfactants in the emulsion system. When the hydrophilicity and lipophilicity of a surfactant are well balanced in an ME system, the ME frequently possesses a bicontinuous structure, in which the water phase and the oil phase coexist on a microscopic scale. Unique polymer morphologies such as continuous porous monolithic, bicontinuous hybrid, and nanosheet structures were prepared by polymerization or gelation in BMEs.
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The field of polymer nanocomposites is of rapidly growing interest. Mixing or fusion of polymers with inorganic nanospecies (e.c. nanosilica and clay) can lead to enhanced mechanical properties and improved fire retardancy. Recently, synthesis of particulate or colloidal organic/inorganic hybrids, called core-shell particles has been intensively interested. One of core-shell type, particles-on-a particle has been intensive study in a decade. Most of the studies have been conducted with inorganic solid particles, which are nano-scaled dispersion such as silica with 10nm size. Their nanocomposites in which polymer particles (core) are highly armored by silica particles (sol) have been obtained by the polymerization methods using aqueous alcoholic media, and hydrophilic initiators. We have realized the novel preparation method using aqueous dispersion polymerization in static condition to synthesize poly(methyl methacrylate, MMA)-silica colloidal composites in which submicron-scale silica particles embedded with the surface of PMMA particles.
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The great structural possibilities of siloxane molecules lead to a unique variety of chemical structures but also makes rational synthetic control difficult. Among the unlimited structural varieties, polyhedral oligomeric silsesquioxane (POSS) molecules, which possess a nanocage structure, have been studied as a novel class of nanomaterials both from fundamental and industrial aspects. The alternating siloxane copolymers, which consisted of a bifunctional POSS cage and a flexible linear dimethyloligosiloxane (DMS) chain segment, were researched. We have reported two novel synthetic methodologies to produce necklace-shaped POSS siloxane polymers by stepwise polycondensation and equilibrium polymerization of octamethylcyclotetrasiloxane.
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The chromatography properties of various lipopolysaccharides (LPSs) adsorbents and recent findings concerning methods for eliminating LPS from protein solns. using the adsorption technique were described. Lipopolysaccharide is an amphipathic substance that has both an anionic region (the phosphoric acid groups) and a hydrophobic region (the lipophilic groups). Consequently, an LPS-selective ligand should have, not only cationic properties, but also hydrophobic properties. Chromatog. matrixes with polycationic ligands are presented. Effects of various factors on the sepn. of biopolymers by polycationic adsorbents are addressed as well, specifically, effect of pore size of the adsorbent on LPS selectivity and effect of degree of ligand polymn. on adsorption of biopolymer. Chromatog. results for selective LPS removal are also given. It has been shown that poly(ε-lysine)-cellulose spherical particles can reduce the concns. of natural LPS to 1 EU/mL or lower in drugs and fluids used for i.v. injection, at a neutral pH and ionic strengths of μ=0.05-0.4. Generally, it is important to not only select a suitable ligand, but also to adjust the pore size of the matrix, to achieve selective removal of LPS.
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