Microfluidic Synthesis Of High-Performance Monodispersed Chitosan Microparticles For Methyl Orange Adsorption

Dyestuff wastewater produced from chemical industry is a main and serious part causing water pollution. But because of its complex composition, poor biodegradability, treatment is at home and abroad recognized difficult. Current treatment is mainly adsorption process, this method still faced with poor reproducibility, irregular shape of the adsorbent, low capacity for the targeted pollutants, and adsorbent further cause environmental pollution. Droplet microfluidics is a new branch of technology in the field of synthetic materials in recent years. Microfluidic technology has the potential to prepare high monodispersed structure, structure of double and high order emulsion/particle and complex composition new materials full of combined functions. Therefore, the combination of microfluidic technology with environment-friendly material to seek new ways to develop and research new high-performance adsorbent work will have great significance.In this work, we used laser ablation and hot pressing sealing to prepare PMMA single emulsion microfludic chip. Also we selected good biocompatibility and environmental friendliness chitosan material and form emulsion in microfluidic chips combined with outside crosslinking reaction solidification. Thus prepared a high monodispersed and efficient adsorbent targeting for azo dye methyl orange. We also perform evaluation in its morphology, isothermal adsorption characteristics, adsorption kinetics and the environment variables. The results showed high sphericity of chitosan microspheres, particle size distribution and high monodispersity (CV=1.86%), which show good preparation repeatability. The isotherm fit with Langmuir-adsorption, the maximum adsorption capacity of up to 182mg/g, adsorption kinetics consistent with Pseudo-second-order model, and can be effectively reused even after several regenerations. On this basis, the above microsphere was used as nanometer TiO2 powder catalyst load, in order to prepare chitosan/TiO2 composite microspheres. Photocatalytic dye degradation experiments showed that this kind of composite microspheres can accelerate the dye decolorizing process by the combination of adsorption and photocatalytic, and this kind of chitosan/TiO2 composite microsphere can also achieve self-cleaning.