Preparation method of polypropylene super-hydrophobic surface with rolling angle controllable

Abstract

The invention belongs to the technical field of super-hydrophobic material preparation and relates to a preparation method of a polypropylene super-hydrophobic surface with the rolling angle controllable. The preparation method comprises the steps that a polypropylene aggregate mold is pressed into polypropylene sheets with the thickness being 10 micrometers to 2 centimeters through a press vulcanizer; 2-4 layers of the polypropylene sheets are stacked and pressed together in a die through the press vulcanizer; then the stacked and pressed polypropylene sheets are cooled to indoor temperature or transferred onto a curved die and attached to the curved die and then cooled to the indoor temperature; and finally the stacked and pressed polypropylene sheets are stripped by hands, pincers or a universal testing machine, and the polypropylene super-hydrophobic surface with the rolling angle controllable is obtained. The method is simple and feasible, the principle is scientific, the operation is easy and convenient, the preparation cost is low, the environmental friendliness is achieved, the prepared super-hydrophobic sheets and a container are quite high in contact angle, and the rolling angle is controllable.

Description

Technical field: [0001] The invention belongs to the technical field of superhydrophobic material preparation, and relates to a method for preparing a superhydrophobic surface of polypropylene with controllable rolling angle. Background technique: [0002] Hydrophobicity is one of the important characteristics of the material surface, which is determined by the chemical composition and micro-geometric structure of the surface. When a droplet comes into contact with a material surface, it either maintains the droplet shape or spreads to form a liquid film on the surface, a property usually measured by the water contact angle (WCA). Surfaces with a contact angle greater than 150° and a rolling angle less than 10° are generally referred to as superhydrophobic surfaces. The unique surface properties of superhydrophobic materials make them widely used in fields such as waterproof, antifouling, antifog, self-cleaning, fluid drag reduction, microfluidic chips, and antibacterial. ...

AI Technical Summary

Problems solved by technology

The rolling angle of the polypropylene surface is determined by the surface adhesion. Water droplets on the low-adhesion superhydrophobic surface are easy to roll and slide even with a slight inclination (<10°). The contact angle between the water droplet and the high-adhesion superhydrophobic surface is greater than In the case of 150°, tilting the surface by 90° or even 180°, water droplets still adhere to the surface. This property is used to manipulate droplets at the micron scale, which can be used in microfluidic systems, non-destructive transfer of liquids, and biotechnology. Playing a major role, Chinese patent CN101070408B discloses a superhydrophobic polypropylene film or block with controllable rolling angle and its preparation method. Polypropylene is dissolved in a solvent as a solution, and after shearing, heat treatment, cooling, phase separation / crystallization and solidification Forming, drying and other processes form a film or block with a crystalline network structure of different shapes. The minimum rolling angle of water droplets on the surface of the film or block can reach 0-1°, and the maximum can reach 90° or 180°. Rolling does not occur, and the contact angle between the surface of the film or block material and water is greater than 150°. The process of this method is complicated, the cycle is long, and the processes such as shearing and crystallization are difficult to control. The preparation process requires a large amount of organic solvents, which is difficult for large-scale production. Chinese patent CN101768396A discloses a blended modified polypropylene superhydrophobic coating or film and preparation method thereof with controllable rolling angle, the preparation process is similar to Chinese patent CN101070408B; Li Yupeng et al. 144) and Li Shengyao (Master's thesis of Dalian University of Technology, 2012) reported the superhydrophobic surface with controllable rolling angle obtained by oxygen capacitively coupled radio frequency plasma etching on the surface of polypropylene, by controlling the plasma treatment time, aging time and aging temperature , can obtain highly adhesive superhydrophobic surface and non-adhesive superhydrophobic surface, but plasma etching technology equipment is expensive, and the effect of polymer surface modification will obviously decay with time, and plasma technology is currently mainly used in laboratories small-scale experiments, there is still a considerable distance from large-scale production

In addition, there is no report on the green and simple preparation method of curved polypropylene superhydrophobic container.

[0005] In summary, superhydrophobic polypropylene surfaces with controllable rolling angles (from ultra-small rolling angles where water droplets are hardly stable to super-large rolling angles where water droplets do not roll when tilted by 90° or 180° on the surface) have been reported. However, the current method has problems such as cumbersome process, difficult control, long cycle, high cost and environmental pollution.

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