Self-Assembly of Ternary Particles for Tough Colloidal Crystals with Vivid Structure Colors

Self-assembly of colloidal spheres is the most frequently used method for structural colors, but the chroma of the structural colors is usually so low that people cannot observe it under natural conditions. This paper presents a facile method for fabrications of vivid structural colors by doping carbon black into the self-assembly of colloidal polymer spheres and nanosilica particles. This approach can generate very gorgeous structural colors which can be very easily seen under natural conditions. The fabrication conditions for the self-assembly of composite dispersions of polymer/silica/carbon black were optimized to obtain colloidal crystals with vivid colors. Thus, robust mechanical properties, large-scale, and brilliant structural colors can guarantee the obtained crystal films to find practical applications, which are demonstrated by the fact that the successful applications of structural colors beautify the original simple and tedious surface of bamboo strand board (BSB)

INFLUENCE OF SOLVENT TREATMENT ON MOULD RESISTANCE OF BAMBOO

Bamboo timber is very vulnerable to mould fungi, a characteristic that is attributed to the rich sugar, starch, and protein present in bamboo. Solvents including cold water, hot water, benzene/ethanol, ethanol/ether, 1% NaOH, and 1% HCl can dissolve corresponding components from bamboo, which might be helpful to the resistance of bamboo against mould fungi. In order to study the relationship between surface nutrition and mildew of bamboo, mould resistances of bamboo blocks treated with different solvents were tested in the laboratory and field. Results showed that bamboo treated with cold water, hot water, benzene/ethanol or ethanol/ether had almost the same resistances with the controls against mould fungi, and the surfaces became covered with mycelium within 10 days in laboratory tests, and 5 weeks in field tests. 1% NaOH and 1% HCl were helpful to the mould resistance of bamboo, of which, 1% HCl treatments behaved the best, especially in the field tests

Self-assembly of colloidal spheres and application as solvent responding polymer film

It is the first time to fabricate and apply responsive colloidal crystal (CC) films on biocomposite material - bamboo strand board (BSB). The responsive film can be easily prepared directly through the self-assembly of soft colloidal polymer spheres containing hydrophilic monomers at ambient pressure and temperature without complicate equipment. In this approach, soft colloidal polymer spheres are synthesized by emulsion polymerization using polymerizable emulsifier. Then, the polymer latex is loaded onto the surface of BSB. The colloidal polymer spheres can directly self-assemble into a robust and transparent colloidal crystal (CC) film on BSB. Neither soft matrix nor posttreatment is needed. Compared with the traditional responsive CC, the polymer film on BSB not only had sensitive response behaviors but also had good reversibility and mechanical strength, which would provide a new method for fabrication and application of responsive CC. © 2012 Elsevier Inc.Financial supports of this research from the NSF (No. 30700628), Zhejiang innovative group (2010R50023) and talents foundation from Zhejiang Agriculture and Forestry University (2011FR041) are appreciated.Peer Reviewe