Reactive processing of recycled polycarbonate/acrylonitrile butadiene styrene.

Cellular phone housings were ground to make original particulates using a knife mill. Foams and adhesives with a lighter density than water were removed from ground mixtures using a sink-float process in water; ground metals, button rubbers, and wires were separated from desired materials by using a sink float process in salt All housing materials, consisting of seven thermoplastics included in cellular phone housings, showed better tensile properties than pure housing materials made of polycarbonate/acrylonitrile butadiene styrene, but they only had about half of the impact strength. In contrast, the low impact strength for all housing materials was improved by adding 25 wt % polyethylene elastomer and/or 2.4 wt % ground epoxy circuit boards for batch mixing. Impact strengths, tensile strengths, and the energy absorption ability of all housing materials were improved by adding 5.4wt% glycidyl methacrylate for twin screw extrusion.

Purification of His-tagged proteins using Ni2+-poly(2-acetamidoacrylic acid) hydrogel.

In this study, a new matrix for immobilized metal affinity chromatography (IMAC) using poly(2-acetamidoacrylic acid) (PAAA) hydrogels complexed with Ni(2+) was developed for the purification of the recombinant histidine-tagged green fluorescence protein (His6-GFP). The Ni(2+)-complexed PAAA hydrogel was prepared by polymerizing 2-acetamidoacrylic acid (AAA) and 2,2'-[(1,4-dioxo-1,4-butanediyl)diamino] bis(2-propenoic acid) (DBDBPA) with potassium persulfate in DMSO, followed by Ni(2+) complexation. Confocal laser scanning microscopy was used to determine the binding of His6-GFP to the Ni(2+)-PAAA hydrogel in three-dimensional space. Photoluminescence spectroscopy revealed an 81% binding efficiency of His6-GFP to the Ni(2+)-PAAA hydrogel yielded with a recovery of 59%. The specificity of His6-GFP binding to Ni(2+)-PAAA hydrogel was compared with that of the PAAA hydrogel without Ni(2+). His6-GFP was purified directly from the cell lysate with Ni(2+)-PAAA hydrogel matrix but the PAAA hydrogel without Ni(2+) had no effect. The major advantage of the Ni(2+)-PAAA hydrogel system over current methods, such as Ni-nitrilotriacetic acid (NTA) agarose beads, was the simple and low-cost procedure for preparing the matrix.

Optical and electrochemical detection of saccharides with poly(aniline-co-3-aminobenzeneboronic acid) prepared from enzymatic polymerization.

Boronic acid-based sensors for saccharides have been developed via biocatalysis. The self-doped copolymer of poly(aniline-co-3-aminobenzeneboronic acid) [poly(aniline-co-AB)], with various mole ratios of two components, was synthesized by oxidative enzymatic polymerization using a natural biocatalyst such as horseradish peroxidase together with an anionic polyelectrolyte template (sulfonated polystyrene) under mild conditions (pH 4.5). Poly(aniline-co-AB), having an aniline boronic acid-to-aniline ratio of 1:2 on average, gave rise to a green doped polymer with absorption maxima at 745 nm. The potentiometric detection of saccharides using poly(aniline-co-AB) is presented. Characteristics of both transient and steady-state response associated with the complex formation of poly(aniline-co-AB) with various saccharides were monitored by UV-vis spectroscopy and cyclic voltammetry (CV). The results obtained from UV-vis spectroscopy and CV show that the sensitivity of enzymatically synthesized water-soluble poly(aniline-co-AB) for various saccharides was improved significantly compared to the chemically synthesized counterpart. A possible mechanism for the sensitive detection of sugar molecules by boronic acid is proposed on the basis of UV-vis and IR spectrophotometry, and four-point probe conductivity measurements.