Monitoring of copper(II) ion is critical for water safety. Herein, a solid phase extraction (SPE) column filled with home-made sulfonated PS-DVB microspheres was adopted to eliminate interference from other co-existing ions. Meanwhile, 1-(2-pyridylazo)-2-naphthol (PAN) as colorimetric reactant was dispersed in polyvinyl butyral (PVB) and immobilized on the filter paper. The as-fabricated paper-based microfluidic analytical device (μPAD) combined with home-made SPE column was utilized for the selective and quantitative determination of copper(II) ion. The selectivity and sensitivity for copper(II) ion were significantly enhanced by SPE-combined μPAD. The sensor has a noticeable color change in the presence of copper(II) ion. The limit of detection was as low as 0.340 μM, which is much less than the drinking water guidelines in many countries and organizations. This technology is convenient and does not need any expensive instrumentation and professional skills. It is easily used to achieve rapid and on-site assessment of copper(II) ion in real-world situations.
Yuling Shi,Qing Liu,Qianqian Pan,Danlong Yang,Tao Wang
Polymer@metal core-shell microspheres are widely used in anisotropic conductive adhesives (ACAs). Styrene-divinylbenzene copolymer (PS-DVB) copper core-shell microspheres (PS-DVB@Cu) with high conductivity and anti-oxidation performance were successfully prepared by combining copper nanoparticles (Cu NPs) and electroless plating copper. The Cu NPs served as catalytic seeds, substituting noble metals to promote electroless deposition . Using environmentally benign ammonia borane as the reductant to replace toxic formaldehyde, the dense copper film was deposited on the surface of PS-DVB microspheres. The thickness of the Cu layer and bulk electrical resistivity of PS-DVB@Cu were tuned by controlling the concentration of the reducing agent. The minimum resistivity of PS-DVB@Cu was 3.27 × 10 −6 Ω·m and merely slightly changed in the air for two months. The prepared PS-DVB@Cu-based ACAs could be effectively applied to anisotropic conductive connections in small-scale circuits with satisfactory anisotropic conductivity.
Yufeng Shen,Huiliang Geng,Feifang Zhang,Zongying Li,Bingcheng Yang
A polyethyleneimine (PEI)-functionalized polymer substrate polar stationary phase was prepared for hydrophilic interaction chromatography (HILIC) by grafting PEI onto poly(styrene-divinylbenzene) (PS-DVB) microspheres. The phase shows a U-shape retention profile and it exhibits typical hydrophilic characteristic when the organic solvent fraction in the mobile phase is > 60%. Hydrogen bonding, anion exchange, and hydrophobic interaction are involved in the retention mechanism. Good separation and unique selectivity for acidic, basic and neutral polar analytes were achieved. It showed extremely low column bleed (comparable to that of blank) under gradient elution mode (even to 50% fraction of water) and wide pH tollerance range (at least 1–13).