Fabrication of highly efficient ultraviolet absorbing PVDF membranes via surface polydopamine deposition

Abstract

Polydopamine (PDA) layers and particles self-polymerized by dopamine have ultraviolet (UV) absorbing property besides versatility and adhesive ability. Herein, a facile strategy for preparing poly(vinylidene fluoride) (PVDF) membrane coated with a thick PDA layer was developed to decrease UV transmittance through the surface modification of PVDF membrane. The PVDF membrane was modified by PDA deposition after pretreated with KOH/alcohol and KMnO 4 /KOH solution. Furthermore, we investigated the effect of coating conditions such as concentration of dopamine and Tris-HCl buffer solution, coating time, and temperature on the performance of membranes. The characterization results indicated that it is more conductive for PDA deposition on the surface PVDF-OH films than original PVDF films. Most importantly, UV transmittance of PVDF-OH film modified in dopamine solution under optimum condition for one time can decrease to as low as 0.122% at 320 nm, which showed excellent UV-shielding property.

Synthesis of carbon quantum dots to fabricate ultraviolet‐shielding poly(vinylidene fluoride) films

“…PVDF film was first treated with an alkaline solution to make the film more hydrophilic . The specific experimental steps and conditions were the same as the optimal one that was reported previously . The pretreated film was designated as PVDF‐OH.…”

“…To yield some new characteristics, many studies are still ongoing. However, there are very few studies on the preparation of ultraviolet (UV)‐absorbing PVDF films . PVDF has a high transmittance at 200–800 nm, so it shows no UV‐protecting performance.…”

“…dispersed ZnO nanoparticles into a PVDF substrate via a melt‐compounding method to improve the UV resistance of PVDF materials. In our previous work, three effective approaches were utilized to make UV‐absorbing PVDF films . The aim of this work is to fabricate a UV‐shielding top coat made of CQDs and PVA via a facile surface‐modification method.…”

“…However, there are very few studies on the preparation of ultraviolet (UV)-absorbing PVDF films. [21][22][23] PVDF has a high transmittance at 200-800 nm, so it shows no UVprotecting performance. Modified PVDF films with ultrahigh UVproof performance play a crucial role in protecting the underlying substrates of airship envelope materials, photovoltaic back sheets, and other outdoor composite materials from UV radiation.…”

“…In our previous work, three effective approaches were utilized to make UVabsorbing PVDF films. [21][22][23] The aim of this work is to fabricate a UV-shielding top coat made of CQDs and PVA via a facile surface-modification method. First, CQD particles were prepared by a simple and low-cost hydrothermal reaction.…”