基于坡缕石制备的稳定超双疏涂层

Preparation of Stable Superamphiphobic Coatings Based on Palygorskite

水、油接触角大于150°的超双疏表面,因其在防污、防粘、防腐、自清洁和管道运输等方面具有巨大的应用潜力而备受关注。但因为超双疏表面结构的脆弱性,目前制备出的超双疏涂层仍具有稳定性不足和价格高昂的问题。使用溶胶-凝胶法在坡缕石(palygorskite,pal)表面原位生长二氧化硅(SiO_(2))并进行氟化改性,制备高含氟量的pal@SiO_(2)-F填料,利用分层喷涂的方法将pal@SiO_(2)-F填料与聚二甲基硅氧烷(PDMS)结合,制备出具有超双疏性的PDMS/pal@SiO_(2)-F涂层。pal@SiO_(2)-F填料中氟元素含量达到了33.14%,涂层的水、白矿油接触角分别达到160°和158.2°。电镜观察发现,复合涂层表面的微米尺度pal颗粒与表面生长的SiO_(2)纳米突起堆积,共同构成双重粗糙结构。PDMS作为粘结剂,为涂层与基底提供稳定的结合力,pal颗粒为表面的纳米结构提供支撑,使涂层捕获的气膜能够稳定存在,涂层在经历白矿油浸泡和腐蚀测试后,仍表现出优异的拒液性,同时在自清洁测试中展现出优异的自清洁性和抗污性。PDMS/pal@SiO_(2)-F超双疏涂层凭借其独特的制备方法和性能及相对低廉的制造成本展示出广泛应用的潜力。

The challenges posed by liquid–solid infiltration phenomena,such as icing on transmission lines,corrosion on ship surfaces,blockage in oil pipelines,and fogging on car windows,significantly impact both industrial productivity and daily life.Inspired by the natural world,including lotus leaves,pitcher plants,and water striders,researchers have sought to develop biomimetic anti-wetting surfaces to address these issues.Superamphiphobic surfaces,characterized by water and oil contact angles exceeding 150°,have drawn considerable attention for their potential in anti-fouling,anti-sticking,anti-corrosion,self-cleaning,and pipeline transportation applications.However,the inherent fragility of the superamphiphobic surfaces'dual rough structure poses a significant challenge in creating durable superamphiphobic coatings.In this study,micron-sized irregular pal particles were utilized as precursors to develop pal@SiO_(2)-F fillers,with polydimethylsiloxane(PDMS)serving as the binder due to its outstanding bonding strength,corrosion resistance,and elasticity.A nano-scale SiO_(2)rough structure was in situ synthesized on the pal particles'surface through a modified sol-gel method.Subsequently,the pal@SiO_(2)particles underwent fluorination using 1H,1H,2H,2H-perfluorodecyltriethoxysilane(PFDTES)to create pal@SiO_(2)-F fillers with a high surface fluorine conten.Layered spraying of the binder and filler yielded PDMS/pal@SiO_(2)-F superamphiphobic coatings with exceptional stability.The surface morphology and chemical composition of the pal@SiO_(2)-F fillers were characterized using scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),Fourier transform infrared spectroscopy(FT-IR),and X-ray diffraction(XRD).The analyses showed that the originally smooth pal particles acquired notable nano-projections in the form of short rods,which interlocked to form numerous pores on the surface of the pal@SiO_(2)-F.The nano-protrusions on the pal particles are composed of amorphous silica,confirming successful in-situ growth of silica on the pal particle surfaces.The fluorine content in the pal@SiO_(2)-F filler reached 33.14%,illustrating effective grafting of high fluorine groups onto the pal@SiO_(2)particles.Surface structures of the PDMS/pal@SiO_(2)-F coatings,observed via SEM,reveal that micron-scale pal particles and SiO_(2)nano-protrusions on the pal surface collaborate to create a dual rough structure.PDMS serves as the binder,ensuring stable adhesion between the coating and substrate while supporting the micron-sized pal particles.This support enables the surface nanostructure to stably capture a gas film attributing to the coating’s adaptability across diverse environments.This adaptability is further bolstered by PDMS's chemical inertness and strong adhesion.In anti-wetting tests,the pal@SiO_(2)-F coating demonstrated remarkable repellency towards various liquids with surface tensions(γ≥30.7 mN/m)and maintained its superamphiphobicity through 50 cycles of white mineral oil immersion.After 12h immersion in NaOH,HCl,and NaCl solutions,the coatings displayed oil contact angles(OCA)greater than 130°and water contact angles(WCA)greater than 150°,retaining their superhydrophobicity and oleophobicity under corrosive conditions and effectively shielding the substrate from infiltration and corrosion.Self-cleaning tests further showcased the coatings'ability to shed water droplets,which removed sand from the surface without leaving residues,even at low inclination angles,highlighting the coatings'superior self-cleaning and anti-fouling properties.Consequently,the superamphiphobic coating,with its distinct features and cost-effective production method,holds potential for broad application in various fields.