scholarly journals Robust Super-Repellent Anisotropic Silica Films by Emulsion-Based Sol–Gel Growth

NANO ◽  
2018 ◽  
Vol 13 (01) ◽  
pp. 1850005 ◽  
Author(s):  
Yingyu Zhou ◽  
Hongling Chen

In this paper, anisotropic SiO2 with different morphologies were synthesized through an emulsion-based one-pot method by adding various silane coupling agents. Silane coupling agents affected the growth of silica nanostructures at the oil/water interfaces. Robust super-repellent film that showed great durability under different harsh conditions were obtained by bonding the self-assembled anisotropic silica nanostructures (ASN) film to substrate by the commercial acrylic adhesive. The film switched from superhydrophobic (157.1[Formula: see text] to superhydrophilic (0[Formula: see text] after being heat-treated at 500[Formula: see text]C. Further, silane treatment with addition of acid reduced the time of modification. Meanwhile, silane grafting density was improved and superhydrophobicity of calcinated ASN films was regenerated.

2017 ◽  
Vol 727 ◽  
pp. 353-358 ◽  
Author(s):  
Jian Hui Luo ◽  
Yuan Yang Li ◽  
Ping Mei Wang ◽  
Bi Bo Xia ◽  
Li Peng He ◽  
...  

Nano-silica was prepared using tetraethylorthosilicate (TEOS) as precursor by sol-gel technology based on stÖber method. These silica nanoparticals were further modified with silane coupling agents, i.e., Hexadecyltrimethoxysilane (HDTMS), dimethoxydiphenylsilane (DMMPS), to introduce organic functional groups on the surface of SiO2 nanoparticles. The Fourier transform-infrared (FTIR) spectra indicated that these silane coupling agents were anchored on the surface of silica particles. And the obtained organic–inorganic hybrid SiO2 particles showed an improvement in hydrophobicity, which can effectively inhibit these silica particles from aggregating.


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 444
Author(s):  
Raluca Somoghi ◽  
Violeta Purcar ◽  
Elvira Alexandrescu ◽  
Ioana Catalina Gifu ◽  
Claudia Mihaela Ninciuleanu ◽  
...  

Nanosized zinc oxide (ZnO) particles modified with different silane coupling agents (octyltriethoxysilane (OTES), octadecyltriethoxysilane (ODTES) and (3-glycidyloxypropyl)trimethoxysilane (GPTMS)) were synthesized in basic catalysis using the sol-gel method. The structure and morphology were characterized by dynamic light scattering (DLS), environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectroscopy (FTIR) for bonding characteristics. The final hybrid materials were deposited on three types of metallic substrates (aluminum (Al), copper (Cu) and zinc (Zn)) in order to obtain coatings with ultrahydrophobic and anti-corrosion properties. Water wettability was studied revealing a contact angle of 145° for the surface covered with ZnO material modified with ODTES. The water contact angle increased with the length of the alkyl chain supplied by the silica precursor. The anti-corrosive behavior of ZnO/silane coupling agents particles deposited on metallic substrates was studied by the linear polarization technique in neutral medium.


2000 ◽  
Vol 73 (3) ◽  
pp. 534-550 ◽  
Author(s):  
Shinzo Kohjiya ◽  
Yuko Ikeda

Abstract The use of the sol—gel process on general-purpose grade rubbers is reviewed in the absence or presence of silane coupling agents. The sol—gel reactions of tetraethoxysilane (TEOS) in epoxidized natural rubber (ENR), styrene—butadiene rubber (SBR) or butadiene rubber (BR) vulcanizates produced silica generated in situ. This silica was found to be a good reinforcing agent by investigating tensile and dynamic mechanical properties and morphology observation by transmission electron microscopy (TEM). The amount of silica formed was limited by the degree of swelling of the rubber vulcanizate by TEOS which was the precursor of the silica. However, the dispersion of silica generated in situ was better than conventionally added silica due to its formation in place. Also, it was noted that the diameter distribution of in situ silica was monodispersed. Silane coupling agents, such as mercaptosilane, aminosilane, and bis(3-triethoxysilylpropyl) tetrasulfide, were compounded in the vulcanizates and their effects on silica generated in situ were evaluated. Their effects were significant. The dispersion of the silica in the rubbery matrix became better and the particle size became smaller and monodispersed, as observed by TEM, which improved mechanical properties. The superior properties of silica generated in situ have been studied further to elucidate the mechanism of reinforcement.


2017 ◽  
Vol 54 (2) ◽  
pp. 341-344
Author(s):  
Anda Ionelia Mihai (Voicu) ◽  
Sorina Alexandra Garea ◽  
Eugeniu Vasile ◽  
Cristina Lavinia Nistor ◽  
Horia Iovu

The goal of this paper was to study the modification of porous clay heterostructures (PCHs) with various silane coupling agents. Two commercial coupling agents (3-aminopropyl-triethoxysilane (APTES) and 3-glycidoxypropyl-trimethoxysilane (GPTMS)) with different functional groups (amine and epoxy groups) were used as modifying agents for the PCHs functionalization. The functionalization of PCH with APTES and GPTMS was evaluated by Fourier transform infrared (FTIR) spectrometry, thermogravimetric analysis (TGA), X-Ray Diffractions (XRD) and BET Analysis. FTIR spectra of modified PCHs confirmed the presence of characteristic peaks of silane coupling agents. TGA results highlighted an increase of weight loss for the modified PCHs that was assigned to the degradation of silane coupling agents (APTES and GPTMS) attached to the PCHs. The XRD results showed that the structure of modified PCHs was influenced by the type of the silane coupling agent. The functionalization of PCHs with silane coupling agents was also confirmed by BET analysis. Textural parameters (specific surface area (SBET), total pore volume (Vt )) suggested that the modified PCHs exhibit lower values of SBET and a significant decrease of total pore volume than unmodified PCHs.


2021 ◽  
Vol 22 (1) ◽  
pp. 109-122
Author(s):  
S. Riaz ◽  
M. Ashraf ◽  
T. Hussain ◽  
M. T. Hussain ◽  
A. Younus ◽  
...  

Author(s):  
Xiaowei Zhang ◽  
Zilong Wang ◽  
Tianhao Li ◽  
Shengjie Zhu ◽  
Dunbo Yu ◽  
...  

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