PAPERmaking! FROM THE PUBLISHERS OF PAPER TECHNOLOGY Volume 7, Number 1, 2021
cooling the coating down from the molten state, the material forms a nanostructured superhydrophobic surface within seconds. This possibility of a fast thermally induced regeneration of nanoscale surface textures creates the potential to restore superhydrophobic coating properties even after mechanical damage caused, among others, by long Ǧ term use and complex processing and machining steps. Therefore, this coating material has great potential for engineering applications such as superhydrophobic wettability of paper surfaces. Depending on a particular application, there are different requirements for the interaction of paper with water. The highest possible water resistance, which is achieved by superhydrophobic properties, is a quality feature for a majority of paper products, such as packaging materials or novel construction materials, since the ingress of moisture is a major cause of paper damage. “ Surface coating of chitosan of different degree of acetylation on non-surface sized writing and printing grade paper”, Nishi Kant, Bhardwaja Yuvraj & Singh Negib, Carbohydrate Polymers , online, 117674. Chitosan is a renewable biopolymer which can be applied on the surface of writing and printing (W&P) grade paper to enhance its different properties. A variety of chitosan is available based on degree of acetylation (DA), molecular weight, viscosity, etc. DA has a profound effect on the performance of chitosan in many applications. Present study compared the performance of different DA chitosan for surface application of W&P grade paper. Chitosan samples of 23%, 16% and 6% DA were studied for their impact on various physical and surface properties of W&P grade paper. Surface coating of chitosan was done at 1.6 ± 0.2 g/m2 (lower dose) and 2.3 ± 0.3 g/m2 (higher dose) on W&P grade paper. Some properties including air permeance, TEA, showed considerable effect of DA in which high DA chitosan outperformed the low DA. Broadly, chitosan with different DA had varied impact on individual properties of paper. “ Developing bagasse towards superhydrophobic coatings”, Chengrong Qin, Wei Wang, Wei Li, Song Zhang & Zerong Li, Cellulose , 28, 3617 – 3630, (2021). Superhydrophobic surfaces have attracted great attention due to their interesting properties. The ever-increasing environmental concern accelerated the development of bio-based superhydrophobic coating materials. As a high-yield agricultural waste, bagasse is cheap, ready available, renewable and biodegradable. It would be an ideal raw material for the preparation of bio-based superhydrophobic coatings to further improve its application value. Although the hydrophobization of bagasse have been reported, the according works mainly focus on the reaction mechanism and/or their oil-absorption properties. As far as we know, the design of bagasse-based superhydrophobic coatings has been uncovered. Herein, mechanically pretreated bagasse was esterified with stearoyl chloride. Spray-coating the suspension of as-synthesized bagasse esters onto various substrates (glass slide, aluminum flake and filter paper), superhydrophobic surfaces were generated. SEM images in combination with the high-resolution C1s XPS deconvolution spectra implied that nano-structured bagasse esters were deposited on the synthesized micro-scaled esters, which was necessary for their superhydrophobicity. The as-prepared superhydrophobic surfaces exhibited good anti-fouling, oil absorption performance and high time/temperature/pH stability. This research would provide a novel perspective for the design of other bio-based superhydrophobic coatings. “ The Influence of Drying Conditions of Clay-Based Polymer Coatings on Coated Paper Properties ”, Petronela Nechita, Coatings , 11(1), 12, OPEN ACCESS. Coatings based on pigment and polymer binders are applied on paper surfaces to improve their surface, optical, and printing properties. Besides the coating composition, the structure and properties of the coated papers are influenced by the coating layer consolidation upon
Technical Abstracts
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