Formula for preparing polyvinylidene fluoride and carbon nanotube composite film and preparation method of formula

Abstract

The invention relates to a formula for preparing a polyvinylidene fluoride and carbon nanotube composite film and a preparation method of the formula. The method comprises the following steps: 1, weighing a certain amount of MWCNTs, taking dimethylformamide (DMF) as a solvent, and carrying out ultrasound treatment on MWCNTs in DMF for 40 minutes to enable MWCNTs to be dispersed fully; 2, drying polyvinylidene fluoride (PVDF) powder in an oven for a period of time before use to remove water; 3, adding the PVDF powder in a MWCNTs / DMF system to prepare a casting solution, violently stirring in constant-temperature water bath at the temperature of 70 DEG C for 4 hours, and enabling the PVDF powder to be dissolved fully to obtain a uniform solution; 4, sealing the obtained casting solution, and leaving the casting solution standstill during the whole night at room temperature to remove foam; 5, scraping the film on a clean glass plate with a 300 mu m film scraping bar, soaking a liquid film, together with the glass plate, in distilled water bath after 1 minute, and washing the film with deionized water to remove a residual solvent after the film is cured and is stripped from the glass plate automatically; and 6, finally, soaking the film in the deionized water for 48 hours, then taking part of the film and naturally air-drying the film at room temperature to obtain the PVDF / MWCNTs composite film. The preparation method is simple, high in operability, low in energy consumption and low in pollution.

Description

technical field [0001] The invention relates to a film-making formula and a preparation method of polyvinylidene fluoride and carbon nanotube flat plate composite film. Background technique [0002] PVDF is a linear semi-crystalline polymer with a glass transition temperature (Tg) of about -39°C, a melting temperature (Tm) of about 160°C, and a thermal decomposition temperature of about 316°C. The linear macromolecular chain structure of PVDF is -CH 2 -CF 2 -, the polymer chain is surrounded by fluorine atoms and hydrogen atoms, so it has excellent chemical stability, thermal stability and mechanical stability, and has the characteristics of acid and alkali corrosion resistance, not easy to degrade, and easy to form a film. Due to -CH 2 -CF 2 The alternating arrangement of - produces polarity, so it can be dissolved in some common polar solvents, such as N, N-dimethylacetamide, nitrogen methyl pyrrolidone, dimethyl sulfoxide, N, N-dimethylformamide , which makes it an i...

AI Technical Summary

Problems solved by technology

However, there are still some problems that limit the further development and application of PVDF membranes, especially in the fields of water purification and separation, such as drinking water production, wastewater treatment, and biological separation.

The key problem is that the surface energy of PVDF is very low, resulting in poor membrane wettability and strong hydrophobicity.

When the treated aqueous solution contains natural organic matter and protein, since there is almost no hydrogen bond between the hydrophobic PVDF membrane and the water molecule in the boundary layer, the surface of the membrane is easy to adsorb protein or natural organic matter in the water, and the pores on the membrane surface If clogged, the water flux is reduced, reducing the service life of the membrane, resulting in more operating costs for replacement and maintenance of membrane modules

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