Publications by authors named "Daichi Nakayama"

Silk fibroin powder and biodegradable polybutylene adipate terephthalate (PBAT)/poly lactide (PLA) blends were melt-mixed together to fabricate natural and synthetic polymers as possible new sources of biomaterials. Morphological observations conducted through scanning electron microscopy indicated poor dispersion of the silk powder agglomerates, which resulted from strong hydrogen interactions between silk powder chains in the PBAT/PLA matrix. Although the silk powder agglomerates decreased the mechanical properties, as silk powder fractions increased, the ternary blend with 10 wt % silk powder still displayed high impact strength of 108 J/m and tensile modulus of 1.

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We report a novel electrochemical sensing system for single-stranded DNA (ssDNA) with a specific sequence based on the catalytic reduction of protons with platinum deposited by the electrochemical reduction of chloro-2,2':6',2''-terpyridine platinum(II) chloride dihydrate (Pt complex) on a glassy carbon (GC) electrode. There was no catalytic property observed for proton reduction at the GC electrode, while the platinum deposited by the reduction of the Pt complex shows the catalytic activity of proton reduction. The intercalation of the Pt complex with double-stranded DNA (dsDNA) decreased the concentration of the free Pt complex with a concomitant diminution in the electrochemical catalytic current due to steric hindrance and a decrease in the diffusion coefficient of the intercalated Pt complex.

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Lower critical solution temperature (LCST) phase transition of glycol ether (GE)-water mixtures induces an abrupt change in osmotic pressure driven by a mild temperature change. The temperature-controlled osmotic change was applied for the forward osmosis (FO) desalination. Among three GEs evaluated, di(ethylene glycol) n-hexyl ether (DEH) was selected as a potential FO draw solute.

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Abrupt changes in effective concentration and osmotic pressure of lower critical solution temperature (LCST) mixtures facilitate the design of a continuous desalination method driven by a mild temperature gradient. We propose a prototype desalination system by circulating LCST mixtures between low and high temperature (low T and high T) units. Water molecules could be drawn from a high-salt solution to the LCST mixture through a semipermeable membrane at a temperature lower than the phase transition temperature, at which the effective osmotic pressure of the LCST mixture is higher than the high-salt solution.

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