Monitoring morphology development and evolution within block copolymer microparticles dispersed in supercritical CO2 using in situ SAXS.

A facile and versatile strategy to fabricate macro- and mesoporous block copolymer microparticles with bespoke characteristics using supercritical CO2.

(2017) Synthesis of polymeric microcapsules by interfacial-suspension cationic photopolymerisation of divinyl ether monomer in aqueous suspension. Polymer Chemistry .

Generally, the analysis of metal ions uses expensive and tedious techniques and involving complicated devices. Here, we developed a colorimetric-based detection of metal ions using green-synthesized of PVA-stabilised silver nanoparticles (AgNPs), which is simple and low cost. The linearity and sensitivity of AgNPs in detecting metal ions were determined from the absorbance and shifting of local surface plasmon resonance (LSPR) band in the visible range. The detection was carried out on Cu(II), Pb(II), Cd(II), Zn(II), and Mn(II). The most sensitive response was obtained on Cu(II) ions, among the five ions tested. The response showed a good linearity (R2 = 0.9886) in the range of 0.2-1.4 ppm of Cu(II). Meanwhile, the sensitivity on Cu(II) resulted in the limit of detection and the limit of quantitation of 0.1609 mg.L−1 and 0.5179 mg.L−1, respectively.

Contamination of the environment by hazardous metal ions has been a major environmental issue for the past several decades. Among several hazardous metals, mercury ion (Hg(II)) is of particular concern as its compounds are extremely toxic. Hence, developing detection methods for traces of Hg(II) ions in aquatic systems is critical for mercury pollution mitigation. One method that can be used to monitor Hg(II) in aquatic systems is colorimetry-based method which is simple, rapid, and low-cost, yet selective and sensitive. The method can be conducted by applying the Localized Surface Plasmon Resonance phenomenon of metal nanoparticles, such as silver nanoparticles. There are non-Hg(II) ions in the aquatic environment that can interfere the measurements. Thus, a selective method is needed to obtain a valid measurement result. Here, we introduced silver nanoparticles-chitosan (AgNPs-Ch) synthesized by chemical reduction as a selective probe of Hg(II) in an aqueous solution. The AgNPs-Ch was synthesized from silver nitrate at 80°C using trisodium citrate and chitosan as reducing agent and stabilizer, respectively. The synthesized nanoparticles were spherical with an average size below 15.0 nm. Moreover, the AgNPs-Ch was selective for Hg(II) with a linearity of 0.9556 in the concentration range of 1 - 5 ppm and was able to detect the ion down to 1.33 ppm.