Synthesis, structure and properties of (4,4'-H₂bipy)[ZnBr₄]

1401-1405The compound [4,4ʹ-H₂bipy][ZnBr₄] (1) has been synthesized via hydrothermal reaction and exhibits an isolated structure based on discrete 4,4ʹ-H₂bipy moieties and tetrahedral metal(II) centre terminally coordinated by four bromide ions. The organic moieties and the inorganic complex dianions are linked via hydrogen bonds forming a sheet structure. Optical absorption spectrum shows a band gap of 3.13 eV, indicating 1 to be a wide gap semiconductor. Luminescent investigation reveals a strong emission in blue region, which may be originating from π→π* charge-transfer interaction of 4,4ʹ-H₂bipy. IR, powder X-ray diffraction (PXRD) and thermogravimetry-differential thermal analyses (TG-DTA) are also reporte

Synthesis, characterization and properties of polyaniline/expanded vermiculite intercalated nanocomposite

The synthesis characterization and conductivities of polyaniline/expanded vermiculite intercalated nanocomposite are presented in this paper. The conductive emeraldine salt form of polyaniline is inserted into the interlayer of expanded vermiculite to produce the nanocomposite with high conductivity. The structures and properties are characterized by transmission electron microscopy x-ray diffraction spectroscopy fourier transform infrared spectroscopy thermogravimetry analysis and by the measurements of conductivity and stability. The results show that an intercalated nanocomposite with high conductivity and stability is obtained. The synthesis conditions are optimized to obtain the highest conductivity which is 6.80 S cm−1

Hotspots, Frontiers, and Emerging Trends of Superabsorbent Polymer Research: A Comprehensive Review

<jats:p>Superabsorbent polymer (SAP) is a kind of functional macromolecule with super-high water absorption and retention properties, which attracts extensive research and has wide application, especially in the areas of hygiene and agriculture. With reference to the Web of Science database, the SAP research literature from 2000 to 2019 is reviewed both quantitatively and qualitatively. By examining research hotspots, top research clusters, the most influential works, the representative frontier literature, and key emerging research trends, a visual panorama of the continuously and significantly increasing SAP research over the past 2 decades was presented, and issues behind the sharp increase in the literature were discovered. The findings are as follows. The top ten keywords/hotspots headed by <jats:italic>hydrogel</jats:italic> highlight the academic attention on SAP properties and composites. The top ten research themes headed by <jats:italic>clay-based composites</jats:italic> which boast the longest duration and the strongest impact have revealed the academic preference for application rather than theoretical study. Academically influential scholars and research studies have been acknowledged, and the Wu group was at the forefront of the research; however, more statistically significant works have been less detected in the last 10 years despite the sharper increase in publications. <jats:italic>Hydrogel</jats:italic>, <jats:italic>internal curing</jats:italic>, and <jats:italic>aerogel</jats:italic> are both current advances and future directions.</jats:p&gt