Hao Jia,Xiong Jing,Wenhui Su,Huimin Yang,Shaohui Fan,Yutong Sun
Bamboo is a sustainable and environment-friendly polymer. In order to investigate the effect of photoaging on the service-life of bamboo, ultraviolet aging (UV-aging), light-avoidance −90 %RH (AL-90 %RH), light-avoidance (AL) and control were continuously monitored for 26 weeks under four kinds of light conditions. The surface color, micro-morphology and surface interfacial composition of comparing various bamboo samples during storage. The results showed that the total color difference for the cortex (9.758 ± 0.712) and pith (1.325 ± 0.075) under AL conditions were lower than the other three sets of storage conditions, and L* values were reduced by 56.42 % and 53.73 %, respectively. In addition, microflora and grooves were formed on the surface of bamboo stored under AL-90 %RH conditions. Meanwhile, catheters were the main channels for the propagation of mycelium in bamboo. Moreover, the Cox/unox value (an oxygenated to unoxygenated carbon ratio of 0.964) increased sharply under these conditions. UV-aging destroyed the texture and structure of bamboo tissue cells and surfaces, degraded the surface lignin content by 18.89 %, and exposed more observable hemicellulose and cellulose functional groups, thus increasing the carbon binding energy and becoming more difficult to degrade. Finally, the Long Short-Term Memory (LSTM) neural network model was used to predict the fading of the surface color and the volatile compounds after aging, and different photoaging color indication systems were established. Exploring the aging mechanism of bamboo during storage is important for promoting the development of bamboo industry and replacing plastic products, and helping in determine the practical applications of the proposed strategies, their economic benefits and limiting of bamboo photodegradation under optimal warehousing conditions. This meet the current requirements of sustainable development by preserving bamboo resources and use instead renewable resources for both environmental and economic benefit.
Hydrophobic metallic coatings have garnered significant scientific and industrial interest due to their exceptional mechanical durability and extensive application potential. A critical yet not fully understood phenomenon associated with certain metallic surfaces is the spontaneous and reversible transition from an initial hydrophilic state to a hydrophobic state over time. This study aims to elucidate the physicochemical mechanisms underlying the time-dependent wettability transition. The Ni based alloy coating, characterized by an intricate, rough hierarchical structure, was successfully fabricated on 304 stainless steel (SS) substrates through electrodeposition. The temporal evolution of the coating's wetting behavior was systematically monitored, confirming a transition from hydrophilicity to hydrophobicity following aging in ambient air. To disentangle the underlying factors contributing to this phenomenon, plasma cleaning was employed to systematically remove adsorbed airborne hydrocarbons from the coating surface. Comparative X-ray photoelectron spectroscopy (XPS) analysis of the surfaces before and after plasma treatment revealed a substantial reduction in the atomic ratio of airborne hydrocarbon groups (from 79.2 % to 62.7 %), accompanied by a notable increase in lattice oxygen content. These findings demonstrate that the observed wettability transition is a multifaceted process arising from synergistic effects involving both physical adsorption of environmental hydrocarbons and concurrent chemical changes occurring on the coating surface. The interaction between adsorbed hydrocarbon molecules and lattice oxygen has been identified as a key driver for the gradual evolution of surface wettability. Collectively, these insights enhance the understanding of dynamic interfacial behaviors exhibited by metallic coatings and establish a fundamental theoretical framework for rational design and optimization of stable hydrophobic metallic surfaces.
危险品化学品经营许可证（带存储）