scholarly journals High Loading Capacity and Wear Resistance of Graphene Oxide/Organic Molecule Assembled Multilayer Film

2021 ◽  
Vol 9 ◽  
Author(s):  
Li Chen ◽  
Gang Wu ◽  
Yin Huang ◽  
Changning Bai ◽  
Yuanlie Yu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Multilayer Films ◽  
Thickness Measurement ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Film Structure ◽  
Silicon Substrates ◽  
Water Contact ◽  
Macro Scale

Taking advantage of the strong charge interactions between negatively charged graphene oxide (GO) sheets and positively charged poly(diallyldimethylammonium chloride) (PDDA), self-assembled multilayer films of (GO/PDDA)n were created on hydroxylated silicon substrates by alternating electrostatic adsorption of GO and PDDA. The formation and structure of the films were analyzed by means of water contact angle measurement, thickness measurement, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Meanwhile, tribological behaviors in micro- and macro- scale were investigated by AFM and a ball-on-plate tribometer, respectively. The results showed that (GO/PDDA)n multilayer films exhibited excellent friction-reducing and anti-wear abilities in both micro- and macro-scale, which was ascribed to the special structure in (GO/PDDA)n multilayer films, namely, a well-stacked GO–GO layered structure and an elastic 3D crystal stack in whole. Such a film structure is suitable for design molecular lubricants for MEMS and other microdevices.

Bio-Inspired In Situ Fabrication of 11-Mercaptoundecanoic Acid Coating on Stainless Steel 304 for Corrosion Protection

2018 ◽  
Vol 913 ◽  
pp. 375-383
Author(s):  
Shuo Tian Sun ◽  
Yan Hua Lei ◽  
Tao Liu ◽  
Run Hua Fan ◽  
Shi Bin Sun
Keyword(s):  
Corrosion Protection ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Film Structure ◽  
Covalent Attachment ◽  
Water Contact ◽  
In Situ Fabrication ◽  
Corrosion Resistance Property

Bio-inspired in situ fabrication of 11-Mercaptoundecanoic Acid was proposed to prepare self-assembled coating of alkanethiolates on SS304 alloy. In this method, the SS304 was coated with a reactive biopolymer – Polydopamine (PDA) by dispersing them in a dopamine solution and mildly stirring at room temperature with subsequent covalent attachment of 11-Mercaptoundecanoic Acid molecules through the interaction between thiol groups and Polydopamine. The formation and surface structure of the coating were characterized by water contact angle measurement, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The electronic properties of such obtained functional film were studied by potentiodynamic polarization curve and EIS in 3.5% NaCl solution. Corrosion protection efficiency near 99 % was evaluated, and the excellent corrosion resistance property could be ascribed to the compact film structure and good seawater stability for modified SS304 surface, especially in limiting the infiltration of Cl-.

Effect of Plasma-Induced Polymerization on Contact Angle of Paper

2011 ◽  
Vol 396-398 ◽  
pp. 1619-1623
Author(s):  
Zhao Ping Song ◽  
Jun Rong Li ◽  
Hui Ning Xiao
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Polymer Grafting ◽  
Hydrophobic Property ◽  
Cellulose Fibres ◽  
Water Contact ◽  
X Ray ◽  
Factors Associated

Hydrophobic modification of cellulose fibres was conducted by plasma-induced polymer grafting in an attempt to increase the hydrophobicity of paper. Two hydrophobic monomers, i.e., butyl acrylate (BA) and 2-ethylhexyl acrylate (2-EHA) were grafted on cellulose fibres, induced by atmospheric cold plasma. Various influencing factors associated with the plasma-induced grafting were investigated, including the contact time and reaction temperature with monomers, and the dosage of monomers. Contact-angle measurement, infrared spectrum (IR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) were used to ascertain the occurrence of the grafting. The results showed that the hydrophobic property of the modified paper sheet was improved significantly after the plasma-induced grafting. The water contact angle on the surface of the paper reached up to higher than125°.

Fabrication of superhydrophobic cotton fabrics through wrapping silica with plasma-induced grafting polymerization

2017 ◽  
Vol 89 (3) ◽  
pp. 401-410 ◽  
Author(s):  
Yongqiang Li ◽  
Chao Zou ◽  
Jianzhong Shao ◽  
Ya’nan Li
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Cotton Fabric ◽  
Photoelectron Spectroscopy ◽  
Contact Angle Measurement ◽  
Cotton Fabrics ◽  
Angle Measurement ◽  
Water Contact ◽  
Washing Durability ◽  
Before And After

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°.

scholarly journals Fabrication and characterization of superhydrophobic and superlipophilic silica nanofibers mats with excellent heat resistance

2016 ◽  
Vol 52 (1) ◽  
pp. 87-92 ◽  
Author(s):  
S. Gao ◽  
H. Watanabe ◽  
K. Nakane ◽  
K. Zhao
Keyword(s):  
Contact Angle ◽  
Heat Resistance ◽  
Photoelectron Spectroscopy ◽  
Treatment Time ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
High Specific Surface Area ◽  
Water Contact ◽  
Water Filter ◽  
Silica Nanofibers

A kind of silica nanofibers (SNF) mats with superhydrophobicity and superlipophilicity as well as excellent heat resistance, had been prepared by modifying of 1, 1, 1, 3, 3, 3-hexamethyldisilazane on electrospun SNF mats. The effects of heat treatment time on properties of modified SNF mats were investigated by scanning electron microscopy, nitrogen absorption analysis, X-ray photoelectron spectroscopy, and contact angle measurement. With high specific surface area 240.1 m2/g, the optimal modified SNF mat approached water contact angle (WCA) 153.2? and fuel contact angle (FCA) 0?, furthermore, even after annealing by 450?C in air for 1h , WCA remained at 135.5? and FCA kept at 3.8?, which opened a new way to improve heat resistance of fuel-water filter paper.

scholarly journals Preparation and Characterization of a Hydrophilic Polysulfone Membrane Using Graphene Oxide

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 ◽  
...  
Keyword(s):  
Contact Angle ◽  
Graphene Oxide ◽  
Water Contact Angle ◽  
Water Flux ◽  
Feed Solution ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Inversion Method ◽  
Water Contact ◽  
Polysulfone Membrane

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.

Adsorption of Hyperbranched Polysiloxysilane Modified with Triethoxy Group onto the Silicon Wafer

2007 ◽  
Vol 19 (5-6) ◽  
pp. 700-710 ◽  
Author(s):  
Yasuko Yamada ◽  
Tomoyasu Hirai ◽  
Ryohei Kikuchi ◽  
Teruaki Hayakawa ◽  
Masa-Aki Kakimoto
Keyword(s):  
Contact Angle ◽  
Silicon Wafer ◽  
Photoelectron Spectroscopy ◽  
Dynamic Contact Angle ◽  
Dynamic Contact ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Wafer Surface ◽  
Water Contact ◽  
Silicon Wafer Surface

Triethoxysilyl functionalized hyperbranched polsiloxysilanes at the focal (FT-HBPSs) and terminal (TT-HBPSs) positions were synthesized to investigate adsorption behavior onto a silicon wafer surface. The surface of the silicon wafer adsorbed with the HBPSs was characterized by X-ray photoelectron spectroscopy, atomic force microscopy (AFM), static and dynamic water contact angle measurements. The AFM images indicated the formation size of dot-like structures were approximately 200 nm. The presence of vinyl terminal groups of FT-HBPSs permitted conversion of the surface from a non-polar hydrocarbon to a polar hydroxylated or carboxylated structures. After the polarity was changed, the surface properties were also studied using the above surface analysis techniques. The dynamic contact angle measurement indicated that the silicon wafer surface modified by FT-HBPSs was more hydrophilic in water than TT-HBPS. This behavior can be explained by the difference of connecting points between HBPS and the silicon wafer surface.

Metallization Process for Polydimethylsiloxane (PDMS) Rubber

2007 ◽  
Vol 1009 ◽  
Author(s):  
Stéphane Béfahy ◽  
Sami Yunus ◽  
Véronique Burguet ◽  
Jean-Sébastien Heine ◽  
Etienne Dague ◽  
...  
Keyword(s):  
Plasma Treatment ◽  
Photoelectron Spectroscopy ◽  
Soxhlet Extraction ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Oxygen Plasma Treatment ◽  
Water Contact ◽  
Electrical Failure ◽  
Static Water ◽  
Hydrophobic Recovery

AbstractA process to fabricate stretchable and adherent gold tracks on flat silicone rubber substrates is studied by X-ray photoelectron spectroscopy (XPS), static water contact angle measurement, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The process involves several steps: curing flat silicone substrate; removing uncured oligomers by hexane Soxhlet extraction; pre-stretching the substrate; activating the strained silicone surface by an oxygen plasma treatment; coating the strained substrate with 5nm titanium and 80nm gold layers by e-beam evaporation; and finally releasing the sample. The plasma treatment creates a thin brittle silica-like layer that temporarily increases the substrate's surface energy. Indeed the plasma treatment is followed by a hydrophobic recovery. As a consequence, the delay between plasma treatment and metal deposition has to be reduced as much as possible. The silica-like layer can be nicely observed after release. Its thickness is estimated to be around 20nm to 50nm. The entire process allows us to obtain stretchable metallized samples that remain conductive even after an excessive deformation leading to electrical failure.

Effects of Surface Treatments of Polycaprolactone Scaffolds on their Properties

2013 ◽  
Vol 747 ◽  
pp. 178-181 ◽  
Author(s):  
Wasana Kosorn ◽  
Boonlom Thavornyutikarn ◽  
Wanida Janvikul
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Alkaline Hydrolysis ◽  
Photoelectron Spectroscopy ◽  
Atomic Ratio ◽  
Contact Angle Measurement ◽  
Contact Angles ◽  
Angle Measurement ◽  
Water Contact ◽  
Oh Groups

Polycaprolactone (PCL) was surface modified with alkaline hydrolysis by NaOH and/or low pressure oxygen (O2) plasma treatment. The hydrolysis was conducted in two different stages: one was performed prior to PCL scaffold fabrication by a high pressure supercritical CO2 technique; the other was carried out after the fabrication. The resulting hydrolyzed PCL scaffolds, with pore sizes in the range of 150-250 μm, were denoted as pre-HPCL and post-HPCL, respectively. Both non-hydrolyzed and hydrolyzed PCL scaffolds were subsequently subjected to the plasma treatment, to further enhance the hydrophilicity of the scaffolds. The surface morphology, wettability and chemical composition of all PCL scaffolds were analyzed by scanning electron microscopy (SEM), water contact angle measurement, and X-ray photoelectron spectroscopy (XPS), respectively. It was found that the surface of the scaffolds turned from fairly smooth to highly rough after the hydrolysis and plasma treatment, particularly when both treatments were in use. The post-hydrolysis induced more surface roughness, compared to the pre-hydrolysis. In addition, the water contact angles on the scaffolds enormously reduced after the treatments; plasma treatment, however, showed a more prominent effect than the alkaline hydrolysis. Although expressing a zero-degree contact angle, the plasma-treated pre-HPCL scaffold was wetted more readily than the plasma-treated post-HPCL. These were in good agreement with the XPS results; interestingly, the plasma-treated pre-HPCL scaffold exhibited the greatest O/C atomic ratio among the PCL scaffolds. This indicated its highest extent of PCL chain oxidation, a degradation of ester groups into-COOH and-OH groups.

scholarly journals Silicalite-1 Layers as a Biocompatible Nano- and Micro-Structured Coating: An In Vitro Study on MG-63 Cells

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3583 ◽  
Author(s):  
Martina Doubkova ◽  
Ivana Nemcakova ◽  
Ivan Jirka ◽  
Vitezslav Brezina ◽  
Lucie Bacakova
Keyword(s):  
Photoelectron Spectroscopy ◽  
Chemical Properties ◽  
In Vitro Study ◽  
Ammonium Hydroxide ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Orthopaedic Implants ◽  
Water Contact ◽  
Physico Chemical

Silicalite-1 is a purely siliceous form of zeolite, which does not contain potentially harmful aluminum in its structure as opposed to ZSM-5 aluminosilicate types of zeolite. This paper reports on a study of a silicalite-1 film, deposited on a silicon Si(100) substrate, as a potential anti-corrosive and biocompatible coating for orthopaedic implants. Silicalite-1 film was prepared in situ on the surface of Si(100) wafers using a reaction mixture of tetrapropyl-ammonium hydroxide (TPAOH), tetraethyl-orthosilicate (TEOS), and diH2O. The physico-chemical properties of the obtained surface were characterized by means of X-ray photoelectron spectroscopy, water contact angle measurement, atomic force microscopy, and scanning electron microscopy. The biocompatibility was assessed by interaction with the MG-63 cell line (human osteosarcoma) in terms of cell adhesion, morphology, proliferation, and viability. The synthesized silicalite-1 film consisted of two layers (b- and a, b-oriented crystals) creating a combination of micro- and nano-scale surface morphology suitable for cell growth. Despite its hydrophobicity, the silicalite-1 film increased the number of initially adhered human osteoblast-like MG-63 cells and the proliferation rate of these cells. The silicalite-1 film also improved the cell viability in comparison with the reference Si(100) substrate. It is therefore a promising candidate for coating of orthopaedic implants.

scholarly journals Osteoinduction Evaluation of Fluorinated Hydroxyapatite and Tantalum Composite Coatings on Magnesium Alloys

2021 ◽  
Vol 9 ◽  
Author(s):  
Zheng Cao ◽  
Li Li ◽  
Linjun Yang ◽  
LiLi Yao ◽  
Haiyan Wang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Composite Coatings ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Implant Design ◽  
Water Contact ◽  
Thermal Synthesis ◽  
X Ray ◽  
Wide Range ◽  
Novel Strategy

Magnesium (Mg) alloys have a wide range of biomaterial applications, but their lack of biocompatibility and osteoinduction property impedes osteointegration. In order to enhance the bioactivity of Mg alloy, a composite coating of fluorinated hydroxyapatite (FHA) and tantalum (Ta) was first developed on the surface of the alloy through thermal synthesis and magnetron sputtering technologies in this study. The samples were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS) mapping, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and water contact angle measurement (WCA), which characterized the surface alternation and confirmed the deposition of the target FHA/Ta coating. The results of cell morphology showed that the MC3T3-E1 cells on the surface of Mg/FHA/Ta samples had the largest spreading area and lamellipodia. Moreover, the FHA coating endowed the surface with superior cell viability and osteogenic properties, while Ta coating played a more important role in osteogenic differentiation. Therefore, the combination of FHA and Ta coatings could synergistically promote biological functions, thus providing a novel strategy for implant design.

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