Low-density polyethylene super hydrophobic sheets/containers with controllable rolling angle and preparation method thereof

Abstract

The invention belongs to the technical field of super hydrophobic material preparation, and relates to low-density polyethylene super hydrophobic sheets / containers with controllable rolling angle and a preparation method thereof. The preparation method comprises the steps: firstly, carrying out mold pressing of low-density polyethylene granules into 10 [mu]m-2 cm low-density polyethylene sheets by a plate vulcanizing machine; overlaying 2-4 low-density polyethylene sheets together in a mold with the plate vulcanizing machine; then cooling the together-overlaid low-density polyethylene sheets to room temperature, or transferring to a curved-surface mold to be laminated with the curved-surface mold and then cooling to room temperature, stripping the together-overlaid low-density polyethylene sheets better with hands, an iron tong or a universal testing machine, and thus obtaining the low-density polyethylene super hydrophobic sheets / containers. The method is simple and feasible, scientific in principle, simple to operate, low in preparation cost and friendly to environment; and the prepared super hydrophobic sheets / containers have quite high water contact angle and have controllable rolling angle.

Description

Technical field: [0001] The invention belongs to the technical field of preparation of superhydrophobic materials, and relates to a low-density polyethylene superhydrophobic sheet / container with controllable rolling angle and a preparation method thereof. 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, microfluid...

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Problems solved by technology

[0003] Low-density polyethylene (LDPE) is a common thermoplastic, which is widely used in all aspects of production and life. The research on superhydrophobicity of LDPE has attracted much attention (references: QianfengXu, BikashMondal, AlanM.Lyons, ACS Appl. Mater. Interfaces, 2011, 3: 3508-3514; J. Fresnais, J.P. Chapel, F. Poncin-Epaillard, Surface & Coatings Technology, 2006, 200: 5296–5305; Steven M. Hurst, Bahador Farshchian, Junseo Choi, Jinsoo Kim, Sunggs A and S Park, Colloids : Physicochem.Eng.Aspects, 2012, 407:85–903; Zhang Chunyu, Cai Hongguang, Chen Bin, Dong Weimin, Mu Zhiyuan, Zhang Xuequan, Acta Catalytica Sinica, 2008, 29(1):1-3; Lin Feiyun, Feng Jie, Huang Mingda, Zhong Mingqiang, Journal of Functional Polymers, 2010,23(2):211-214; Feng Jie, Lin Feiyun, Zhong Mingqiang, Journal of Materials Science and Engineering, 2010,28(6):835-838), but the practical application The main reasons for the little progress are: First, many preparation methods involve specific equipment, special templates with micro-nano structures, harsh conditions and long periods, which are difficult to use for large-scale preparation of super-hydrophobic surfaces; Many methods require chemical modification with low surface energy substances, such as fluorine or silicon-containing compounds, which are expensive and increase product costs; third, many methods require a large amount of chemical reagents and solvents, which involve environmental and pollution issues; four There are very few reports on superhydrophobic low-density polyethylene with controllable rolling angle

Chinese patent CN102627799B discloses a super-hydrophobic low-density polyethylene film material and its preparation method. In this invention, the low-density polyethylene and nano-zinc oxide particles are evenly mixed to prepare a film by extrusion casting or calendering. Soak in acetic acid solution to fully dissolve the nano-zinc oxide particles, take them out and dry them to obtain a super-hydrophobic low-density polyethylene film. Zinc reaction removal; Chinese patent CN104387606A discloses a method for preparing low-density polyethylene superhydrophobic surface by candle burning method. The method coats hot-melt adhesive on the low-density polyethylene film, and then ignites the candle to make the candle produced by burning Dust is deposited on a low-density polyethylene film to prepare a super-hydrophobic surface. The preparation conditions of this method are harsh and the rolling angle of the surface cannot be adjusted; Chinese patent CN102909813A discloses a linear low-density polyethylene / linear low-density polyethylene, linear low-density polyethylene A method for preparing a superhydrophobic film of an ethylene / polypropylene blend. Although the method does not use a solvent or a template, steps such as preparing the blend and mixing are added, which increases the process and cost. The above-mentioned patents CN102627799B, CN104387606A, and CN102909813A all The roll angle cannot be regulated by experimental conditions

Li Yupeng et al. (Y.P.Li, S.Y.Li, W.Shi, M.K.Lei, Surface & Coatings Technology, 2012, 206: 4952–4958; Dalian University of Technology master's degree thesis, Li Shengyao, 2012; Dalian University of Technology master's degree thesis, Hao Yinhu, 2010) reported Oxygen capacitively coupled radiofrequency plasma etching was performed on the surface of low-density polyethylene to obtain a superhydrophobic surface with controllable rolling angle. By controlling the plasma treatment time, aging temperature and aging time, a highly adhesive superhydrophobic surface (contact angle: 151 °, rolling angle: the surface is inclined at 90° or even 180° and still adheres) and low-adhesion superhydrophobic surface (contact angle: ~153°, rolling angle: 3±0.4°), but plasma etching technology equipment is expensive, polymer The effect of surface modification will obviously attenuate over time, and plasma technology is currently mainly used in small-scale experiments in laboratories, and there is still a considerable distance from large-scale production

In addition, there is no report on the green, simple and low-cost preparation method of curved low-density polyethylene superhydrophobic container.

[0005] In summary, there are superhydrophobic low-density polyethylene surfaces with controllable rolling angles (from ultra-small rolling angles where water droplets can hardly be stabilized to super-large rolling angles where water droplets do not roll when they tilt 90° or 180° on the surface). reported, but the current method has problems such as cumbersome process, difficult control, long cycle, high cost and environmental pollution.

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