Search

Natural fibers are available as an essential substitute for synthetic fiber in many applications. However, the sensitivity of Chinese Windmill Palm or Trachycarpus Fortune Fiber (TFF) to water causes low interfacial bonding between the matrix and the fiber and at the end reduces the mechanical properties of the composite product. Alkaline treatment improves mechanical properties and does not affect water absorption. Hence, additional treatment in the coating is required. This study uses alkaline treatment and coating modification using blended chitosan and Acrylated Epoxidized Soybean Oil (AESO). Blend coating between AESO and chitosan is performed to increase water absorption and mechanical properties. TFF water resistance improved significantly after the coating, with water absorption of the alkaline/blend coating-TFF of 3.98 % ± 0.52 and swell ability of 3.156 % ± 0.17. This indicated that blend coating had formed a cross-link of fiber and matrix after alkalization. Thus, the single fiber tensile strength increased due to the alkaline treatment, and water absorption decreased due to the coating. The combination of alkaline treatment and blend coating on TFF brings excellent properties, as shown by the increase in tensile strength in both single fiber test and composite., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Many naturally-derived organic coating has been proposed for corrosion protection of carbon steel, but its effectiveness is challenged by poor coating adhesion. In this work, chitosan was extracted from Nila tilapia fish scales and coated onto ASTM A36 carbon steel surface by using electrophoretic deposition (EPD) and dip coating (DC) techniques. The work aims at determining the coating technique and process parameters that result in effective corrosion protection of carbon steel in acid solution. The effectiveness of corrosion protection was determined by calculating inhibition efficiency from corrosion parameters obtained by polarization test and electrochemical impedance spectroscopy. Results showed that each coating technique provides different mechanism of corrosion protection. The DC-made coating showed a physisorption mechanism where the steel's corrosion rate increases as the temperature increased. The EPD-coated specimens demonstrated a chemisorption mechanism with its minor change in corrosion rates than those of DC-coated specimens. The DC technique resulted in a higher inhibition (73 %) efficiency and lower corrosion rate than that of EPD (41 %) with some degree of stability over increasing temperature. [ABSTRACT FROM AUTHOR]

A study on the effect of chitosan chelating agent on the formation of spinel LiMn2O4 using sol-gel method is reported. Chitosan was added into a precursor solution containing lithium and manganese ions and then was heated at 600 °C to form spinel LiMn2O4. Chitosan chelating agent performed better in precursor solution at pH 4 than at pH 8. X-ray diffraction demonstrated that samples prepared with chitosan resulted in higher weight percentage of spinel LiMn2O4 compared to samples prepared without chelating agent or with citric acid. Combination between chitosan and citric acid resulted in the highest weight percentage of spinel LiMn2O4 compared to other samples, amounted to 91%, with crystallite size of 47 nm. Scanning electron microscopy images showed that chitosan helps to direct the formation of pyramid-like structure and decrease the particles’ size and agglomeration. Chitosan was also employed as a template to obtain spinel LiMn2O4 with high surface area via formation of porous structure with the highest resulting surface area of 18 m2/g. [ABSTRACT FROM AUTHOR]