Preparation And Application Of Structure-tunable Superwetting Polystyrene And Its Composites

Superwetting materials have a wide range of applications in many fields due to their selective affinity for oil and water.It is one of the hot topics in current research.The chemical composition and microstructure of the surface are critical to the regulation of wettability,and determine the applications of superwetting materials.For this reason,low-surface-energy polystyrene and its composite materials were selected as the research object in this thesis,and their wettability was adjusted effectively through the variation in structure.Their applications in the fields of biological detection,micro-droplet transmission and oil/water separation were developed.The main research contents are as follows:1.The superhydrophobic polystyrene films with low water sliding angle were prepared by electrospinning.They are composed of "popcorn" micro/nano composite structure and nanofiber network.By using these films as the detection substrates,a new microdroplet detection technology for protein was developed,and rapidly qualitative and sensitively quantitative detection of bovine serum albumin was achieved.Superhydrophobic surface ensures the formation of spherical droplets,and the amount of sample to be measured was thus decreased from traditional hundreds of microliters to ten microliters,reducing the waste of the reagent effectively.Low water sliding angle is helpful to improve the operability of the droplets.The concentration of the droplets to be tested increased the detection sensitivity by 16 times.This microdroplet detection technology of protein has a certain degree of universality.This study provides new technical guidance for the highly sensitive detection of trace biological/chemical molecules.2.The superhydrophobic ZnO/polystyrene composite films were prepared by electrospinning.They have beads-on-string micro/nano composite structure.Their water sliding angles were adjusted in the range of 4-180° by virtue of the photocatalysis of ZnO.Based on this,the patterned water sliding angle was realized by controlling the photo-irradiation area,and the droplets were collected in specific areas.A superhydrophobic surface with water sliding angle gradient was obtained by synergistically controlling the time and area of photo-irradiation,and the droplets were transmitted in specific track.This study shows a broad application prospect in the fields of image encryption,information transfer and microfluidics.3.The silica/polystyrene composite films were prepared by electrospinning.They have porous beads-on-string micro/nano composite structure.The construction of porous structure contributed to the realization of superhydrophobic and superoleophilic properties due to the increasing surface roughness and the capillary force between oil and the films.Rapid oil/water separation can be achieved in eight seconds,and the oil sorption capability increased with the increase in viscosity of the oil.The maximum oil sorption capacity was up to 122.7 g/g,which is at a relatively high level in the related fields.These superhydrophobic-superoleophilic micro/nano composite films have shown great potential in rapid and efficient oil/water separation,and might be used to solve the environmental pollution problems caused by various spilled oils.