Effect of Resin Content on the Surface Wettability of Engineering Bamboo Scrimbers

Abstract

Bamboo scrimber refers to a lignocellulosic structural material, which is usually attacked by water, ultraviolet radiation and fungus. Surface coating is an effective way to protect it, and its coating properties depend on surface wettability. In this study, the surface wettability of bamboo scrimbers with varying resin content was investigated via the comprehensive analysis of surface roughness, surface contact angle, surface free energy, surface chemical composition and coating properties. The resultant scrimbers had a similar profile with low roughness. Their surface was hydrophilic, but the hydrophilicity decreased with the increase in resin content. High resin content gave rise to low total free energy, in which the Lifshitz–van der Waals component was dominant and it decreased with the increasing resin content. Meanwhile, the ratio of the electron-accepting component to the electron-donating component becomes higher. This was due to the decreasing hydrophilic groups (e.g., -OH and -COOH groups) and the increasing oxygen-free groups (e.g., C-H and -CH2 groups) on the scrimber surface. The resin content affected the adhesion by decreasing the surface wettability, but the coating adhesion still reached the level of 2 for all bamboo scrimbers. The results will provide a theoretical reference for the surface coating of bamboo scrimbers in the structural application for good coating durability.

Screening of Ionic Liquids against Bamboo Mildew and Its Inhibition Mechanism

“…However, bamboo and its products are highly susceptible to mildew growth caused by fungi such as Penicillium citrinum, Trichoderma viride, and Aspergillus niger in warm and humid environments. The factors contributing to bamboo mildew growth can be attributed to the high content of nutrients, such as starch, sugar, and protein, present in bamboo, which provide a suitable substrate for mildew growth [26,27], as well as the external environmental conditions of high humidity (≥93%) and temperature (20-30 • C), which favor mildew growth on bamboo surfaces [28,29]. Notably, the black spots resulting from mildew contamination are difficult to remove by conventional methods, resulting in significant economic losses and resource wastage [28,30].…”