Robust Superhydrophobic/Superoleophilic Filter Paper with TiO₂ Nanoparticles for Separating Oil–Water Mixtures and Surfactant-Stabilized Water–Oil Emulsions

Abstract

Superwetting materials for oil−water separation have attracted increasing research attention recently. Developing cost-effective and highefficiency filter materials to separate oil−water mixtures and stable water−oil emulsions is challenging. Herein, the TiO 2 nanoparticles were first hydrophobically modified using γ-aminopropyltriethoxysilane, and then polydimethylsiloxane was subsequently added to obtain a stable superhydrophobic coating. The superhydrophobic filter paper was obtained via roll coating. The water contact angle on the coated filter paper exceeded 152°, and the oil droplets were quickly absorbed by the coated filter paper. The superhydrophobic filter paper was used for separating various immiscible oil−water emulsions, with separation efficiencies of >99.5%. In addition, the synthesized filter paper can effectively separate various surfactant-stabilized water−oil emulsions. The separation efficiency was satisfactory even after 10 cycles. When the volume ratio of water in water−oil emulsions reached 20%, the separation efficiency exceeded 97.5%. The results indicate that the superhydrophobic/superoleophilic filter paper exhibits satisfactory oil−water separation ability and is environmentally friendly, cost effective, and easy to implement, making it suitable for continuous industrial production.

Preparation of superhydrophobic conductive micro/nano‐graphite/PDMS films on paper by simple spraying method

“…There are a large number of hydroxyl groups (OH) on the surface of the original filter paper, and because the filter paper has a certain rough structure, which leads to the original filter paper has a good hydrophilicity, 23 as shown in Figure 5a. Micro–nano graphite flake and PDMS were stirred and dispersed violently in absolute ethanol, and the graphite flake was coated with a certain amount of PDMS.…”

“…The PDMS in the coating thus showed a sudden change in the contact angle of the samples from 0 to6 h, and the contact angle of the coatings began to decrease slowly when heating was continued, as shown in Figure 7d. When the heat resistance test time exceeds 24 h, the coating loses its superhydrophobic properties, which may be due to the deformation of the substrate cellulose in a long period of high temperature leading to micro‐ and nanostructures on the surface of the coating, which further affects the contact angle and rolling angle changes of the superhydrophobic coating 23 . In summary, the superhydrophobic coating improves the comprehensive performance of the original filter paper, which can meet the use requirements in various harsh environments and further expand the application scenarios of filter paper.…”

Enhancing flame retardancy, thermal stability, and superhydrophobic of paper through Na₂O·nSiO₂ and PDMS modification

“…Its versatility nds applications in packaging, furniture, and other elds (Wen and Guo 2020; Zhang et al 2023). However, the inherent hydrophilicity and ammability stemming from natural cellulose bers limit its service life and potential applications (Li et al 2022).…”

Superhydrophobic Hexadecyltrimethoxysilane-Modified Fumed Silica Nanostructure/Poly(butyl methacrylate) Composite Thin Films via Aerosol-Assisted Deposition: Implications for Self-Cleaning Surfaces

“…Superhydrophobicity arises due to two important factors, namely, (1) surface chemistry and (2) surface nano- and microroughness. The careful control of these two parameters has enabled the development of artificial SH materials that have applications in, for example, self-cleaning surfaces, oil–water separation, and anti-fogging materials. − …”