TEOS/silane coupling agent composed double layers structure: A novel super-hydrophilic coating with controllable water contact angle value

2017 ◽  
Vol 185 ◽  
pp. 2209-2216 ◽  
Author(s):  
Hu Yan ◽  
Wang Yuanhao ◽  
Yang Hongxing
Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2254
Author(s):  
Adeleke A. Oyekanmi ◽  
N. I. Saharudin ◽  
Che Mohamad Hazwan ◽  
Abdul Khalil H. P. S. ◽  
Niyi G. Olaiya ◽  
...  

Hydrophilic behaviour of carrageenan macroalgae biopolymer, due to hydroxyl groups, has limited its applications, especially for packaging. In this study, macroalgae were reinforced with cellulose nanofibrils (CNFs) isolated from kenaf bast fibres. The macroalgae CNF film was after that treated with silane for hydrophobicity enhancement. The wettability and functional properties of unmodified macroalgae CNF films were compared with silane-modified macroalgae CNF films. Characterisation of the unmodified and modified biopolymers films was investigated. The atomic force microscope (AFM), SEM morphology, tensile properties, water contact angle, and thermal behaviour of the biofilms showed that the incorporation of Kenaf bast CNF remarkably increased the strength, moisture resistance, and thermal stability of the macroalgae biopolymer films. Moreover, the films’ modification using a silane coupling agent further enhanced the strength and thermal stability of the films apart from improved water-resistance of the biopolymer films compared to unmodified films. The morphology and AFM showed good interfacial interaction of the components of the biopolymer films. The modified biopolymer films exhibited significantly improved hydrophobic properties compared to the unmodified films due to the enhanced dispersion resulting from the silane treatment. The improved biopolymer films can potentially be utilised as packaging materials.


Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3956
Author(s):  
Jea Uk Lee ◽  
Jin-Yong Hong

The surface modification of recycled plastic film-based aggregates was investigated to improve the compatibility between the aggregates and a cement paste. Surface modification was performed using ultraviolet–ozone treatment (UV-O3), a silane coupling agent, O2 atmospheric pressure plasma, and acrylic binder coating methods. The surface properties of the modified aggregates were analyzed using a contact angle measuring instrument. The results revealed that for all surface modification methods, the contact angle decreased with an increase in the treatment time. According to the comparative evaluation results of the changes in the surface characteristics of the aggregates through various surface modification methods, the contact angle reduction rates were 58.9%, 51.4%, 25.5%, and 24.5% for the O2 atmospheric pressure plasma, the acrylic binder coating, the silane coupling agent, and the UV-O3 method, respectively. After 48 h, the contact angle had increased by 110.9%, 29.9%, 16.4%, and 5.9% for the O2 atmospheric pressure plasma, UV-O3, the silane coupling agent, and the acrylic binder coating, respectively. Namely, the surface modification using the acrylic binder coating method was found to be the most effective method in terms of the wettability increase effect and the long-term storage stability.


2012 ◽  
Vol 622-623 ◽  
pp. 420-425
Author(s):  
Alex Kwasi Kumi ◽  
Allan Chelashaw ◽  
Yu Mei Zhang ◽  
Li Feng Li

Ceramic coatings based on sol-gel method have increasingly gained much attention in recent times. In order to ascertain important experimental factors (variables) influencing surface properties, such as adhesion, pencil hardness and advancing contact angle (non-stick) of sol coatings, a 26-1-factorial screening design with six experimental variables, precursor mole ratio, low surface energy polymer concentration, silane coupling agent (SCA) concentration, silica nanoparticles concentration (SNP’s),curing temperature and three responses ( surface properties) were investigated. The results indicate that silane coupling agent concentration, SNP’s concentration and their interaction were the most significant experimental factors influencing advancing contact angle. None of the experimental factors studied were statistically significant with respect to hardness and adhesion.


2019 ◽  
Vol 48 (3) ◽  
pp. 237-242 ◽  
Author(s):  
Feilong Shi ◽  
Jia Xu ◽  
Zhanzhu Zhang

Purpose This study aims to prepare UV protection and hydrophobic fabric through modifying cotton fabric by graphene oxide and silane coupling agent. The graphene oxide and silane coupling agent (KH570) are anchored on the cotton fabric by a stable chemical bond. Design/methodology/approach Graphene oxide was prepared by modified Hummers method. The fabric sample was treated with graphene oxide and silane coupling agent KH570 using simple dipping-padding-drying method. The effects of the dosage of graphene oxide, silane coupling agent KH570 and curing temperature were determined by single variable experiment and orthogonal experiment, The UVA and UVB transmittances in ultraviolet light of the sample fabric were characterized, and the contact angle test method with water was used to indicate the hydrophobicity of the sample fabric. The structure and surface of the fabric were analyzed using Fourier-transform infrared spectroscopy and scanning electron microscopy. Findings The cotton fabric was successfully modified by graphene oxide and silane coupling agent KH570. Compared with the untreated fabric, the surface of the fabric was smooth, and there was no gap on the fiber. The graphene oxide, silane coupling agent KH570 and cotton fabric combined tightly. The UPF value of the modified fabric was 50+, and the contact angle reached 138.1°. It had excellent UV protection and hydrophobic properties. Research limitations/implications Although graphene oxide and silane coupling agents KH570 had successfully endowed the cotton fabric with good UV protection and hydrophobic properties, graphene oxide and silane coupling agent KH570 are expensive and used in large quantities. There are certain limitations in the actual life and production process. Practical implications After treating with silane coupling agent, the hydrophilic fabric treated with graphene oxide is being translated into hydrophobic, and graphene oxide bonded with cotton. The modified fabrics also have excellent UV protection. This fabric can be used for outdoor sports such as clothes and tents. Originality/value Cotton fabric treated with graphene oxide generally by simple dip-dry-cure method is hydrophilic and graphene oxide is easy to drop. The usage of silane coupling agent KH570 as a crosslinking agent to link graphene oxide and cotton fibers has not been reported yet. The modified fabrics have both UV protection and hydrophobic properties.


2013 ◽  
Vol 634-638 ◽  
pp. 3048-3051
Author(s):  
Zhong Yuan Wu ◽  
Liang Hu ◽  
Jia Xi Chen

Surface hydrophobic modification of T-ZnOw was experimented with silane coupling agent KH-570(gamma-(methylpropyl acyloxy)trimethoxysilane). It was shown by FT-IR that the whiskers was modified by silane coupling agents molecular compounded with the Zn-OH of whiskers. The effect of grafted modification with KH570 on hydrophobicity of T-ZnOw was characterized with dispersion stability test in an organic solvent and measuring the contact angle between the whiskers on distilled water. The results showed that surface treatment of T-ZnOw with KH570 improves hydrophobicity of whiskers simultaneously, and the modified whiskers have much slower settling rates than the pristine whiskers in the liquid paraffin. The contact angle between the modified whiskers with distilled water is 137.75 degrees, which is a significant increase.


2012 ◽  
Vol 583 ◽  
pp. 350-353 ◽  
Author(s):  
Hai Yun Jiang ◽  
Ruo Mei Wu ◽  
Chen Guo ◽  
Wei Li Zhang ◽  
Zhi Qing Yuan ◽  
...  

A superhydrophobic coating was prepared on the surface of aluminum alloy. The adherence and the hydrophobicity were observed by adherometer and optical contact angle meter, respectively. The affection of silane coupling agent KH550 was also investigated by the analysis of FTIR. The result indicated that the coating owns satisfactory adherence and the hydrophobicity. The treatment of KH550 increases the polar of the surface, which is responsible for the superior adherence. A similar micro-nano structure is mainly attributed to the hydrophobicity. When the density of PP-g-MAH is 1.7 % (mass ratio), the coating shows an optimum super-hydrophobicity and its water contact angles are at range of 163.0-163.9°.


2020 ◽  
Author(s):  
Muayad Al-shaeli ◽  
Stefan J. D. Smith ◽  
Shanxue Jiang ◽  
Huanting Wang ◽  
Kaisong Zhang ◽  
...  

<p>In this study, novel <a>mixed matrix polyethersulfone (PES) membranes</a> were synthesized by using two different kinds of metal organic frameworks (MOFs), namely UiO-66 and UiO-66-NH<sub>2</sub>. The composite membranes were characterised by SEM, EDX, FTIR, PXRD, water contact angle, porosity, pore size, etc. Membrane performance was investigated by water permeation flux, flux recovery ratio, fouling resistance and anti-fouling performance. The stability test was also conducted for the prepared mixed matrix membranes. A higher reduction in the water contact angle was observed after adding both MOFs to the PES and sulfonated PES membranes compared to pristine PES membranes. An enhancement in membrane performance was observed by embedding the MOF into PES membrane matrix, which may be attributed to the super-hydrophilic porous structure of UiO-66-NH<sub>2</sub> nanoparticles and hydrophilic structure of UiO-66 nanoparticles that could accelerate the exchange rate between solvent and non-solvent during the phase inversion process. By adding the MOFs into PES matrix, the flux recovery ratio was increased greatly (more than 99% for most mixed matrix membranes). The mixed matrix membranes showed higher resistance to protein adsorption compared to pristine PES membranes. After immersing the membranes in water for 3 months, 6 months and 12 months, both MOFs were stable and retained their structure. This study indicates that UiO-66 and UiO-66-NH<sub>2</sub> are great candidates for designing long-term stable mixed matrix membranes with higher anti-fouling performance.</p>


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