Study On The Controllable Design And Self-cleaning Performance Of ATO@HNTs/PVDF Coatings

Polyvinyl Chloride（PVC）is widely used in construction,automobile,packaging and other fields because of its excellent mechanical properties,good transparency and low cost.However,the surface of PVC film self-cleaning performance is insufficient,and there are problems such as sticky,electrostatic accumulation,when exposed to the outdoor environment for a long time,dust,organic matter and other pollutants once attached to the surface is difficult to clean,thereby shortening the service life of PVC film,resulting in a waste of resources.For a long time,PVDF coating has been used to improve the surface contamination of PVC film,but a single PVDF coating self-cleaning performance is limited,not enough to actively clean surface pollutants.Therefore,to solve the above problems,in this paper,stann-antimony oxide（ATO）was coated on the surface of alloxite nanotubes（HNTs）,and a multifunctional composite filler（ATO@HNTs）with both photocatalytic and conductive properties was prepared.Further,the surface modification of ATO@HNTs composite filler was carried out.Finally,the photocatalytic antistatic self-cleaning PVDF coating and photocatalytic superhydrophobic self-cleaning PVDF coating were prepared on the surface of PVC film.The main research contents of this paper are as follows:（1）Using HNTs as the carrier,ATO was coated on the surface of HNTs by chemical coprecipination method,and core-shell type nano-composite filler ATO@HNTs（AH）was obtained.The surface morphology,crystal structure,chemical valence state and optical properties of AH were analyzed.The growth mechanism of ATO on HNTs surface and the conduction and photocatalytic enhancement mechanism of AH were described.The results showed that when the coating rate of Sn O₂ was 75%,ATO uniformly coated HNTs,AH had low resistivity（200Ω·cm）and excellent photocatalytic performance,and the degradation rate of 100 mg/L Rhodamine B（Rh B）reached 96.02%after 90 min ultraviolet irradiation.（2）AH was modified by ethanolamine（MEA）to obtain MEA-AH（m AH）,and the chemical composition of m AH and its dispersion in PVDF coating were characterized.Then,m AH/PVDF coating was obtained by solution blending method,and coated on the surface of PVC membrane to obtain PVDF/m AH/PVC membrane with good photocatalytic and antistatic properties.The results showed that the dispersion of AH in PVDF was improved after ethanolamine modification,and the mechanical properties of PVDF were enhanced when m AH was 15%.The degradation efficiency of Rh B in PVC film reached 90.06%after 2 h,and the resistivity was reduced to below 10⁸Ωand had good photothermal stability.（3）Using 1H,1H,2H,2H-perfluoro-decyl triethoxysilane（PFDTES）as modifier,hydrophobic modification of AH and Ti O₂ was performed to obtain F-AH and F-Ti O₂,and the surface chemical structure and morphology of the composite filler were characterized before and after modification.Then,the micro-nano structure F-AH/F-Ti O₂-PVDF coating was constructed on the surface of PVC film by spraying method,and finally the photocatalytic superhydrophobic self-cleaning F-AH/F-Ti O₂-PVDF/PVC film was obtained.The results showed that PFDTES were successfully grafted on the surface of AH and Ti O₂.At the same time,when the mass ratio of F-AH to F-Ti O₂ was 1:1,F-AH/F-Ti O₂-PVDF coating constructed a micro-nano rough structure with low surface energy on the surface of PVC film.The surface water contact Angle reached 158°,the oil contact Angle reached 110°,and the UV photocatalytic degradation efficiency reached86.13%.Moreover,it has good superhydrophobic durability.After ultraviolet aging and acid-base corrosion,the surface water contact Angle can still be maintained above 150°.