PAPER making! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL Volume 6, Number 1, 2020
Correlation between the concentration and morphology of copper microparticles and their biocidal effect on paper sheets, P. Contreras et al, Cellulose (2020), online . In this study, different methods for incorporating mixed or laminar copper microparticles (CuMPs) during papermaking were evaluated to determine the optimum paper-making process and correlate particle concentration and shape with antimicrobial activity. The addition of CuMPs during the disintegration of dry pulp stage was observed to produce a paper with uniformly distributed CuMPs, as determined through optical microscopy and UV – Vis spectroscopy analyses by measuring absorbance spectra in different areas of papers. Determination of two indices related to the concentration and distribution of copper will allow to predict the copper content in other papers. CuMP-paper samples were evaluated for structural, optical, and mechanical strength properties according to paper industry standards. Quantitative analyses by atomic absorption showed that between 24 and 39% of CuMPs were embedded in the paper fibre, independent of particle type. Finally, antibacterial activity analyses were performed according to ISO 20645 and ISO 20743. The results showed that papers with 0.30 g of incorporated CuMPs have antimicrobial activity, independent of particle morphology, with effects observed towards Gram (+) and Gram (−) bacteria and fungus. Furthermore, the evaluation of antimicrobial activity at different times of exposure to the microorganisms showed differences in effects that were dependent on the shape of the CuMPs incorporated into paper, where laminar particles exerted a sufficient effect, while no or a slight effect was observed for mixed CuMPs against Aspergillus niger. Facile Fabrication of Transparent Paper with Tunable Wettability for Use in Biodegradable Substrate, Guodong Li et al, Sustainable Chem. Eng., Vol.8(5) . Transparent paper with excellent optical transmittance and mechanical stability shows potential for use in diverse applications as a substrate. Here, we reported a novel alkyd resin-impregnated cellulose transparent (ARICT) paper that exhibited good flexibility, adequate biodegradability, easy scale-up, and tailorable wettability. As the concentration of alkyd resin increased (5 – 15 wt %), the optical transmission of the cellulose paper increased from 70.7% to 93.5% at 550 nm, and its water contact angle increased from 9° to 91°. Furthermore, impregnating the cellulose paper with alkyd resin increased the surface smoothness, thermal stability, and toughness of the paper. After poly(3,4- ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) was coated on one side of the ARICT paper, a flexible single-sided conductive paper with high conductivity was obtained, while the other side retained high insulativity, suggesting that the ARICT paper was a promising substrate for the fabrication of a flexible electrode. Finally, the eco- friendly biodegradability was verified by subjecting the ARICT paper to fungal degradation over time. This study developed a new method for the fabrication of flexible and biodegradable substrates, enabling the development of disposable electronics. PACKAGING TECHNOLOGY Improving sizing performance of middle layer of liquid packaging board containing high-yield pulp, Fangdong Zhang et al, Cellulose (2020), online . As the important part of liquid packaging board, the middle layer is generally produced from a mixed pulp furnish by unbleached softwood kraft pulp and high-yield pulp (HYP). However, the addition of HYP would bring unsatisfactory properties (e.g. hydrophilicity) to liquid packaging board. Herein, in this study, the sizing performance of middle layer of liquid packaging board was evaluated by varying the kraft pulp to HYP ratios of middle layer, the dosage of sizing agent and cationic additives etc. It showed that the edge penetration value and Cobb value of middle layer illustrated a better liquid repellence with the addition of sizing agent. The improved sizing performance of the middle layer of liquid packaging board can be
Technical Abstracts
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