Facile Approach to Develop Hierarchical Roughness fiber@SiO2 Blocks for Superhydrophobic Paper

Abstract

Papers with nanoscaled surface roughness and hydrophobically modification have been widely used in daily life. However, the relatively complex preparation process, high costs and harmful compounds have largely limited their applications. This research aims to fabricate superhydrophobic papers with low cost and nontoxic materials. The surface of cellulose fibers was initially coated with a film of SiO2 nanoparticles via sol-gel process. After papermaking and subsequent modification with hexadecyltrimethoxysilane through a simple solution-immersion process, the paper showed excellent superhydrophobic properties, with water contact angles (WCA) larger than 150°. Moreover, the prepared paper also showed superior mechanical durability against 10 times of deformation. The whole preparation process was carried out in a mild environment, with no intricate instruments or toxic chemicals, which has the potential of large-scale industrial production and application.

Functionalized layered double hydroxides for innovative applications

“…To achieve oil removal from water, superhydrophobic and superoleophilic materials are commonly adopted. [275][276][277][278][279][280] Functionalized LDHs have been shown to offer novel opportunities as adsorbents for oil pollution remediation. 272,281,282 An LDH surface is inherently hydrophilic due to the abundant surface hydroxyl groups.…”

Cellulose and Its Nano-Derivatives as a Water-Repellent and Fire-Resistant Surface: A Review

“…Following surface chemistry development, hydrophobic and superhydrophobic surfaces have presented potential applications such as anti-cohesion, self-cleaning, liquid separation, and printing and re-printing, which are fascinating from both academic and industrial viewpoints [ 16 , 17 , 18 , 19 ]. Before considering the abovementioned surfaces in detail, the wetting behavior is explained by three different modules as follows [ 20 , 21 , 22 , 23 ]: Cassie and Baxter’s equation: cos θ = f 1 cos θ 1 + f 2 cos θ 2 where Sv , Sl , and lv are the surface tension between solid-vapor, solid–liquid and liquid–vapor phases, respectively; θ and θ * w are the contact angles exposed to a smooth and rough surface, respectively; r is defined as the roughness factor; f 1 , f 2 , θ 1 , and θ 2 are, respectively, the surface area fraction and contact angle for substrates 1 and 2, which are valid for a non-homogeneous surface.…”

“…Sustainable and bio-inspired materials can be applied as hydrophobic and superhydrophobic agents, which provide sufficient durability versus liquid droplets. As shown in Figure 1 , a hydrophobic surface presents a water contact angle of more than 90°, whereas a WCA of more than 150° represents a superhydrophobic surface [ 16 , 17 , 18 , 19 ].…”

“…Waterproof surfaces, due to their anti-adhesion and self-cleaning features, have great potential to be utilized for the preservation of ancient books and documents, as a coating layer in high-quality packaging, and pharmaceutical devices that are prone to infection, bacteria, and contaminated surfaces. Water-resistant papers have been investigated for security applications, especially currency notes, which are exposed to dust, microorganisms, and hand sweat, to increase the durability of banknotes against water and moisture [ 16 , 17 , 18 , 19 , 82 , 83 ]. Latthe et al [ 84 ] investigated the use of hydrophobic silica nanoparticles via spray coating for various surfaces such as wood, building walls, fabrics, and banknotes.…”

“…They observed a linear relationship between the concentration and water contact angle. Wang et al [ 16 ] coated a cellulosic surface with nano-silica particles via a sol-gel process, followed by impregnation in hexadecyltrimethoxysilane solution to obtain non-toxic, cost-effective, and superhydrophobic paper (WCA > 150°).…”