scholarly journals Superoleophobic micro-nanostructure surface formation of PVDF membranes by tannin and a condensed silane coupling agent

RSC Advances ◽  
2019 ◽  
Vol 9 (55) ◽  
pp. 32021-32026 ◽  
Author(s):  
Shuman Feng ◽  
Mu Li ◽  
Songfeng Zhang ◽  
Yaowen Zhang ◽  
Bing Wang ◽  
...  

A tannin-based hybrid coating was coated on the PVDF membrane surface through a simple one-step co-deposition of tannin and KH550.

2017 ◽  
Vol 20 (1) ◽  
pp. 99
Author(s):  
Alessandra Pereira Andrade ◽  
Angela Mayumi Shimaoka ◽  
Rubens Corte Real de Carvalho

Objective: The objective of this study was to evaluate the combination effect of surface treatments and bonding agents on bond strength of repairs on aged composite resin. Materials and Methods: One hundred twenty microhybrid composite units (Filtek Z250) aged in distilled at 37ºC water for six months were submitted to different surface treatment prior to resin repairs. Ten specimens were randomly divided into 12 groups: non-treated/no bonding agent (negative control), sandblasting /no bonding agent, silane/no bonding agent, non-treated/ etch-and-rinse; non-treated/one-step self-etch; non-treated/ two-step self-etch; sandblasting/etch-and-rinse; sandblasting/one-step self-etch; sandblasting/two-step self-etch; silane coupling agent/etch-and-rinse; silane coupling agent/ one-step self-etch; silane coupling agent/two-step self-etch. Microshear testing was performed to bond strength assessment. Results: Two-way ANOVA and Tukey’s test (α=0.05) demonstrated significant difference between the surface treatments and adhesive systems. Only no treated surface/etch-and-rinse group showed lower bond strength values when compared to other groups. Conclusion: The considered surface treatments were capable to increase the effectiveness of the repair in composite resin when using the adhesive etch-and-rinse.


2015 ◽  
Vol 34 (5) ◽  
pp. 663-670 ◽  
Author(s):  
Teerapong MAMANEE ◽  
Masahiro TAKAHASHI ◽  
Masatoshi NAKAJIMA ◽  
Richard M. FOXTON ◽  
Junji TAGAMI

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.


2005 ◽  
Vol 04 (01) ◽  
pp. 117-126
Author(s):  
N. L. MA ◽  
P. WU

Using density functional theory, we predicted the solution structure of the hydrolyzed 3–aminopropyltriethoxysilane (h–APS), which is a silane coupling agent commonly used in many industrial applications. We have located five stable minima on the potential energy surface of h–APS in which four of them are "neutral", and the remaining one is zwitterionic (dipolar) in nature. Our calculations suggested that the stability of the most stable form of h–APS in water (denoted as II_N) arose from strong intramolecular OH ⋯ N hydrogen bond. The least stable form is the zwitterionic form (I_ZW), which is estimated to be over 90 kJ mol -1 less stable than II_N. The factors governing the relative stabilities of different forms are discussed.


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