PAPER making! g! FROM THE PUBLISHERS OF PAPER TECHNOLOGY INTERNATIONAL ® Volume 9, Number 2, 2023
COATING “Improving the Optical Properties and Filler Content of White Top Testliners by Using a Size Press”, Mustafa Çiçekler, Tamer Sözbir & Ahmet Tutuş, acs Omega , 2023, 8, 23, 21000 – 21007. This study aims to investigate the impact of coating with ground calcium carbonate (GCC) on the optical properties and filler content of white top testliner (WTT) papers. The paper properties investigated include brightness, whiteness, opacity, color coordinates, and yellowness. The results showed that the amount of filler mineral used in the coating process significantly affected the optical properties of the paper. The use of 15% total solids of GCC in the coating suspension resulted in the highest level of whiteness and improved the brightness value by 6.8%. The use of 7% total solids of starch and 15% total solids of GCC reduced the yellowness index by 85%. However, the use of only 7 and 10% total solids of starch had an adverse effect on the yellowness values. The surface treatment led to a significant increase in the filler content of the papers, with a maximum of 23.8% achieved using a coating suspension with 10% total solids of starch solution, 15% total solids of GCC suspension, and 1% dispersant. The starch and GCC in the coating suspension were found to have a direct impact on the filler content of the WTT papers. The addition of a dispersant improved the uniform distribution of the filler minerals and increased the filler content of the WTT. The water resistance of WTT papers increases due to the use of GCC, while their surface strength remains at an acceptable level. The study demonstrates the potential benefits of the surface treatment in terms of cost savings and provides valuable information on the impact of the treatment on the properties of WTT papers. “Water and oil -resistant paper materials based on sodium alginate/hydroxypropyl methylcellulose/polyvinyl butyral/nano-silica with biodegradable and high barrier properties”, Ruifeng Zhu, Xiaoto ng Fu, Shengnan Jin, Rui Ma, Zhibin He, Dan Zhang & Zghu Long, International Journal of Biological Macromolecules , Vol.225, 15 Jan. 2023, pp.162-171. Despite many technical challenges in the development of safe and environmentally friendly food packaging paper materials with excellent water and oil resistance using simple methods, producing paper-based functional materials using bio- based polymers is currently an important topic in the food packaging industry. In this study, novel water and oil-resistant coatings for the paper were developed through the combination of sodium alginate (SA), hydroxypropyl methylcellulose (HPMC), polyvinyl butyral (PVB), and hydrophobic silica nanoparticles (HSNPs). To impart oil-repellency to paper, SA and HPMC were first mixed uniformly and coated on the base paper, which was pre-treated with calcium chloride solution. A compact and tough coating layer was formed on paper due to the hydrogen bonding between SA and HPMC molecules, and the crosslinking between SA and Ca2+ ions in the base paper. High water resistance of the paper was achieved through the coating of PVB and HSNPs on top of the coating of SA/HPMC. The final coated paper demonstrated outstanding oil resistance (kit rating: 12/12), water resistance (Cobb value: 4.23 g/m 2 ), low water vapor transmission rate (100 g/m 2 ·24 h), and improved mechanical properties. This fluorine-free, and biodegradable barrier paper will find excellent applications in the food packaging industry. “Chitosan coated papers as sustainable platforms for the development of surface - enhanced Raman scattering hydrophobic substrates”, Natercia C.T. Martins, Sara Fateixa & Tito Trindade, Journal of Molecular Liquids , Vol.375, 1 April 2023, 121388. Paper-based sensors for surface-enhanced Raman scattering (SERS) detection of water pollutants have gained much attention in the last decades. However, most of the fabricated paper-based SERS substrates still face some limitations regarding reproducibility and uniformity. In this work, we report the fabrication of hydrophobic paper-
Technical Abstracts
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