Surface hydrophilizing modification of polytetrafluoroethylene/glass fiber fabric through oxidant-induced polydopamine deposition

2019 ◽  
Vol 50 (3) ◽  
pp. 364-379
Author(s):  
Yanfen Zhou ◽  
Liang Jiang ◽  
Zhiqing Jiang ◽  
Shaojuan Chen ◽  
Jianwei Ma

This paper reports surface hydrophilizing modification of polytetrafluoroethylene/glass fiber fabric by employing bio-inspired polydopamine functionalization. The modification process was accelerated by introducing sodium periodate (NaIO4) as oxidant. Surface morphology and chemical composition of the modified polytetrafluoroethylene/glass fiber fabric were characterized by using scanning electron microscopy, atomic force microscopy (AFM), and Fourier transform infrared spectroscopy, respectively. Hydrophilicity of the polytetrafluoroethylene/glass fiber fabric was investigated through water contact angle measurement. It was found that polydopamine successfully deposited on the surface of polytetrafluoroethylene/glass fiber fabric and the uniformity of the polydopamine coating increased with increasing modification time. Water contact angle of polytetrafluoroethylene/glass fiber fabric decreased after polydopamine modification and reached 29° when the sample was treated for 120 min, indicating an improved hydrophilic performance. The formed polydopamine coating was also demonstrated to have reliable chemical and mechanical stability.

2020 ◽  
Vol 1010 ◽  
pp. 602-607
Author(s):  
Maizlinda Izwana Idris ◽  
Mohammed Firdaus Adzhari ◽  
Siti Natrah Abdul Bakil ◽  
Tee Chuan Lee ◽  
Mohamad Ali Selimin ◽  
...  

This work focuses on the fabrication of film based on natural biopolymers for wound healing application. Alginate and chitosan were choosen because of their oustanding properties such as biocompatible, hydrophilic and non-toxic. Earlier, the biopolymer film was fabricated by using alginate 1% wt and chitosan 1% wt. solutions at volume ratios of 99:1 and 97:3. Next, the biopolymer film solution was cross-linked with 1M CaCl2.2H2O for two hours and later dried for 24 hours at room temperature. Then, the surface properties of the prepared biopolymer films were characterised via Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM) and contact angle measurement. It was observed that the surface of the biopolymer film became rougher as the volume of the chitosan increases. This condition was confirmed with average surface roughness, RA for biopolymer film with ratio of 97:3 resulted in higher values. Also it was found that the surface of biopolymer films were hydrophilic after the contact angle was less than 90°. This can be concluded that the biopolymer based on alginate/chitosan is a promising candidate for wound healing materials particularly with good surface properties for faster healing process at the wound areas.


Langmuir ◽  
2007 ◽  
Vol 23 (13) ◽  
pp. 6875-6878 ◽  
Author(s):  
Michael Taylor ◽  
Andrew J. Urquhart ◽  
Mischa Zelzer ◽  
Martyn C. Davies ◽  
Morgan R. Alexander

2014 ◽  
Vol 680 ◽  
pp. 93-96
Author(s):  
Muhammad Hafiz Ab Aziz ◽  
Zaliman Sauli ◽  
Vithyacharan Retnasamy ◽  
Wan Mokhdzani Wan Norhaimi ◽  
Steven Taniselass ◽  
...  

This paper reports on the contact angle measurement analysis on a glass based surface for anodic bonding process cleaned by three distinct cleaning processes. The three types of glass based surface used were silica, pyrex, and soda lime glass. The three cleaning solutions tested in this experiment were RCA, piranha and acetone. Water Droplet Test (WDT) was done to analyze the contact angle of micro droplet on sample surface. It can be done by dropping a droplet of water in constant volume at the fixed height and angle. Only RCA process constantly decreases the contact angle value after cleaning. The compilations of data strongly proved that all samples become hydrophilic after RCA cleaning process. The solid surface is considered hydrophilic when water contact angle is smaller than 90°, and hydrophobic profile if the water contact angle is larger than 90°. Samples which undergo piranha and acetone cleaning did not prove any characteristic of hydrophilic or hydrophobic surface after cleaning.


2017 ◽  
Vol 89 (3) ◽  
pp. 401-410 ◽  
Author(s):  
Yongqiang Li ◽  
Chao Zou ◽  
Jianzhong Shao ◽  
Ya’nan Li

Cotton fabric is commonly used in daily life, but it is easily wetted and contaminated by liquid. Herein, we present a simple and environmentally friendly plasma technology for hydrophobic modification of cotton fabric. In order to endow superhydrophobicity to cotton fabric, helium plasma inducing graft polymerization of 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (D4Vi) was utilized to wrap SiO2 particles on cotton fabrics. Cotton fabrics were successively dipped in silica sol and D4Vi, then treated by plasma. Cotton fabrics before and after modification were characterized by using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and water contact angle measurement. The experimental results showed that the cotton-SiO2-D4Vi consisted of nanoscale SiO2 protrusions and low-surface-energy film polymerized by D4Vi. In addition, the one wrapped SiO2 of 161 nm presented excellent hydrophobicity, washing durability, and repellency toward different types of liquids with a water contact angle of 152°.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Hoan Thi Vuong Nguyen ◽  
Thu Hong Anh Ngo ◽  
Khai Dinh Do ◽  
Minh Ngoc Nguyen ◽  
Nu Thi To Dang ◽  
...  

In general, the polysulfone (PSf) membranes are popular choices for water treatment because they have high thermal stability and good chemical resistance. On the other hand, the filtration capacity of the polysulfone membrane is limited because of its low water flux and poor antifouling ability, which are caused by the low surface hydrophilicity of the membranes. In this research, blending of graphene oxide (GO) or graphene oxide-titanium dioxide (GO-TiO2) mixture into the polysulfone matrix had been carried out through the phase inversion method to enhance the hydrophilic and antifouling properties. Methods such as energy-dispersive X-ray spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, and water contact angle measurement were used to examine the surface properties of the prepared membranes. Experimental results have led to a conclusion that graphene oxide can be stabilized into prepared membranes, and then, by reducing the water contact angle values, the surface of these membranes becomes hydrophilic, which increases the permeability and the water flux of methylene blue from the aqueous feed solution, improving the membrane’s antifouling resistance.


Author(s):  
D. F. Lim ◽  
X. F. Ang ◽  
J. Wei ◽  
C. M. Ng ◽  
C. S. Tan

In this article, a self-assembled monolayer (SAM) is applied onto the copper surface in an attempt to lower the required bonding temperature. Alkane-thiol with 6-carbon chain length is used and tested for bonding experiment. The adsorption of SAM is confirmed by the sharp rise of the water contact angle measurement and the reduced in the surface roughness. Next, the desorption of SAM is done at a high temperature anneal (<300°C) in an inert ambient and its properties are characterized by the water contact angle measurement and XPS. It is found that the water contact angle measurement decreases sharply close back to the contact angle of the pure blanket copper surface after annealing of SAM. The XPS results also show the ability of SAM in protecting Copper surface from oxidation. Finally, shear test is performed on Cu-Cu structures bonded at low temperature (250°C) in order to verify the SAM behavior in protecting the copper surface from oxidation and enhancement for bonding. The wafer pairs with and without SAM are intentionally exposed in clean room environment for few days. The bonded pieces are diced and subject to shear stress and results show that with SAM protection, shear strength is improved due to the enhancement in grain growth as a result of cleaner surface.


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