Characterisation of surface properties of chemical and plasma treated regenerated cellulose fabric

2012 ◽  
Vol 82 (20) ◽  
pp. 2078-2089 ◽  
Author(s):  
Zdenka Peršin ◽  
Alenka Vesel ◽  
Karin Stana Kleinschek ◽  
Miran Mozetič
Keyword(s):  
Plasma Treatment ◽  
Surface Properties ◽  
Photoelectron Spectroscopy ◽  
Research Work ◽  
Contact Angles ◽  
Alternative Activation ◽  
Oxygen Plasma Treatment ◽  
Regenerated Cellulose ◽  
Water Contact ◽  
Chemical Treatments

The aim of this research work was to study the surface properties and sorption characteristics of differently treated regenerated cellulose fabrics. Surface modifications of viscose, modal and lyocell samples caused by using standard chemical pre-treatment procedures were compared to an alternative activation procedure by applying low pressure oxygen plasma treatment. The elemental chemical composition of the modified fabric surfaces was investigated using X-ray photoelectron spectroscopy (XPS), while hydrophilic/hydrophobic properties were evaluated by determining the water contact angles, as well as thoroughly analysed using Owens–Wendt surface energy (SFE) and surface polarity investigations. Standard chemical and also plasma treatments changed the surface chemistry of cellulose. Bleaching and alkaline treatments increased the surface carboxylic acid content by approximately 4.8% while plasma treatment increased it by approximately 9.7%. As a consequence, higher hydrophilicity arises as proved by water contact angle decrease; i.e. 24% (61°) after standard chemical treatments and 70% (20°) after plasma treatment. Both chemical treatments increase the SFE and polar components, while the reduction of dispersive components was less pronounced. The oxygen activation treatment has the greatest influence on the SFEs of the samples as well as on polarity of the samples.

scholarly journals Surface Properties of Pine Scrimber Panels with Varying Density

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 397 ◽  
Author(s):  
Jinguang Wei ◽  
Qiuqin Lin ◽  
Yahui Zhang ◽  
Wenji Yu ◽  
Chung-Yun Hse ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Properties ◽  
Photoelectron Spectroscopy ◽  
Lower Surface ◽  
Contact Angles ◽  
High Density ◽  
Water Contact ◽  
Change Rate ◽  
Hydrophilic Material ◽  
Wood Grain

Coating quality for scrimber products against exterior conditions is largely dependent on the surface properties. The wettability, morphology, and chemical composition of pine scrimber surfaces were investigated to better understand the surface properties. The scrimber was found to be a hydrophilic material because the water contact angles were less than 90°. The panels with a density of 1.20 g/cm3 had the largest angle change rate (k = 0.212). As the panel density increased, the instantaneous contact angle of each test liquid (i.e., water, formamide, and diiodomethane) on the panels decreased, and so did surface free energy. Panels with higher density showed lower surface roughness. Surface roughness across the wood grain was greater than that along the grain. SEM observations showed the high-density panels had a smoother surface with fewer irregular grooves in comparison with the low-density panels. X-ray photoelectron spectroscopy (XPS) analysis indicated that more unoxygenated groups appeared on the surface of high-density panels.

Diamond-Like Carbon Films for Silicon Passivation in Microelectromechanical Devices

1995 ◽  
Vol 383 ◽  
Author(s):  
M. R. Houston ◽  
R. T. Howe ◽  
K Komvopoulos ◽  
R. Maboudian
Keyword(s):  
Contact Angle ◽  
Surface Properties ◽  
Photoelectron Spectroscopy ◽  
Microelectromechanical Systems ◽  
Adhesion Force ◽  
Contact Angles ◽  
Vacuum Arc ◽  
Diamond Like Carbon ◽  
Adhesion Forces ◽  
Water Contact

ABSTRACTThe surface properties of diamond-like carbon (DLC) films deposited by a vacuum arc technique on smooth silicon wafers are presented with specific emphasis given to stiction reduction in microelectromechanical systems (MEMS). The low deposition temperatures afforded by the vacuum arc technique should allow for easy integration of the DLC films into the current fabrication process of typical surface micromachines by means of a standard lift-off processing technique. Using X-ray photoelectron spectroscopy (XPS), contact angle analysis, and atomic force microscopy (AFM), the surface chemistry, microroughness, hydrophobicity, and adhesion forces of DLC-coated Si(100) surfaces were measured and correlated to the measured water contact angles. DLC films were found to be extremely smooth and possess a water contact angle of 87°, which roughly corresponds to a surface energy of 22 mJ/m2. It is shown that the pull-off forces measured by AFM correlate well with the predicted capillary forces. Pull-off forces are reduced on DLC surfaces by about a factor of five compared to 10 nN pull-off forces measured on the RCA-cleaned silicon surfaces. In the absence of meniscus forces, the overall adhesion force is expected to decrease by over an order of magnitude to the van der Waals attractive force present between two DLC-coated surfaces- To further improve the surface properties of DLC, films were exposed to a fluorine plasma which increased the contact angle to 99° and lowered the pull-off force by approximately 20% over that obtained with as-deposited DLC. The significance of these results is discussed with respect to stiction reduction in micromachines.

scholarly journals Adhesion to Bile Drain Materials and Physicochemical Surface Properties of Enterococcus faecalis Strains Grown in the Presence of Bile

2002 ◽  
Vol 68 (8) ◽  
pp. 3855-3858 ◽  
Author(s):  
Karola Waar ◽  
Henny C. van der Mei ◽  
Hermie J. M. Harmsen ◽  
John E. Degener ◽  
Henk J. Busscher
Keyword(s):  
Surface Properties ◽  
Enterococcus Faecalis ◽  
Photoelectron Spectroscopy ◽  
Surface Protein ◽  
Lower Surface ◽  
Contact Angles ◽  
Surface Proteins ◽  
Water Contact ◽  
Zeta Potentials ◽  
Aggregation Substance

ABSTRACT The aim of this study is to determine whether growth in the presence of bile influences the surface properties and adhesion to hydrophobic bile drain materials of Enterococcus faecalis strains expressing aggregation substance (Agg) or enterococcal surface protein (Esp), two surface proteins that are associated with infections. After growth in the presence of bile, the strains were generally more hydrophobic by water contact angles and the zeta potentials were more negative than when the strains were grown in the absence of bile. Nitrogen was found in lower surface concentrations upon growth in the presence of bile, whereas higher surface concentrations of oxygen were measured by X-ray photoelectron spectroscopy. Moreover, an up to twofold-higher number of bacteria adhered after growth in bile for E. faecalis not expressing Agg or Esp and E. faecalis with Esp on its surface. E. faecalis expressing Agg did not adhere in higher numbers after growth in bile, possibly because they mainly adhere through positive cooperativity and less through direct interactions with a substratum surface. Since adhesion of bacteria is the first step in biomaterial-centered infection, it can be concluded that growth in bile increases the virulence of E. faecalis.

The Effects of Surface Modifications on Tin-Doped Indium Oxide Films: Optoelectrical, Wettability and XPS Investigations

2008 ◽  
Vol 373-374 ◽  
pp. 718-721
Author(s):  
Zhi You Zhong ◽  
Feng Lou Sun
Keyword(s):  
Free Energy ◽  
Sheet Resistance ◽  
Surface Properties ◽  
Surface Free Energy ◽  
Indium Oxide ◽  
Photoelectron Spectroscopy ◽  
Surface Modifications ◽  
Optical Transmittance ◽  
Contact Angles ◽  
Oxygen Plasma Treatment

Surface modifications were performed on the tin-doped indium oxide (ITO) substrates for optoelectronic devices, using the different processing techniques. The effects of modification methods on the surface properties of ITO substrates were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), ultraviolet-visible (UV-vis) spectrophotometer, standard goniometry and four-probe meter, respectively. The surface free energy as the sum of the dispersion and polar components was evaluated from the measured contact angles using the Owens-Wendt approach. Experimental results demonstrate that except the optical transmittance of the ITO, the surface properties including the stoichiometry, morphology, wettability and sheet resistance of the ITO substrates strongly depend on the modification methods. Compared with the other treatments, the oxygen plasma treatment increases the oxygen concentration and decreases the carbon concentration, reduces the surface roughness and the sheet resistance, and enhances the surface free energy and the polarity, and thereby more effectively improves the surface properties of ITO substrates.

Surface Modification of Chitosan Membranes by Oxygen Plasma Treatment

2009 ◽  
Vol 610-613 ◽  
pp. 1259-1262 ◽  
Author(s):  
Na Ru Zhao ◽  
Ying Jun Wang ◽  
Li Ren ◽  
Xiao Feng Chen
Keyword(s):  
Contact Angle ◽  
Plasma Treatment ◽  
Water Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Oxygen Plasma ◽  
Chamber Pressure ◽  
Oxygen Plasma Treatment ◽  
Water Contact ◽  
Plasma Irradiation ◽  
Chitosan Membranes

Chitosan membranes were prepared by solvent cast method. In order to increase cell adhesion of the chitosan membranes, oxygen plasma treatment was applied to improve the hydrophilicity of the surface of chitosan membranes. The surface properties were characterized by scanning electron microscopy (SEM), contact angle analyzer, X-ray photoelectron spectroscopy (XPS). The effects of exposure time, plasma generating power, and chamber pressure on water contact angle of the chitosan membranes were investigated. The water contact angle of chitosan membranes decreased from 94.1° to 49.2° after plasma treatment. Which suggested the surfaces became more hydrophilic. XPS analysis showed that the oxygen content and the ratio of O/C increased markedly after oxygen plasma treatment. Furthermore, it was found that C-H bonds were broken with oxygen plasma treatment. C-OH group had been increased after plasma irradiation.

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 Apparent Surface Free Energy of Polymer/Paper Composite Material Treated by Air Plasma

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Konrad Terpiłowski
Keyword(s):  
Surface Roughness ◽  
Free Energy ◽  
Plasma Treatment ◽  
Surface Properties ◽  
Surface Free Energy ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Air Plasma ◽  
Surface Plasma ◽  
Composite Surface

Surface plasma treatment consists in changes of surface properties without changing internal properties. In this paper composite polymer/paper material is used for production of packaging in cosmetic industry. There are problems with bonding this material at the time of packaging production due to its properties. Composite surface was treated by air plasma for 1, 10, 20, and 30 s. The advancing and receding contact angles of water, formamide, and diiodomethane were measured using both treated and untreated samples. Apparent surface free energy was estimated using the hysteresis (CAH) and Van Oss, Good, Chaudhury approaches (LWAB). Surface roughness was investigated using optical profilometry and identification of after plasma treatment emerging chemical groups was made by means of the XPS (X-ray photoelectron spectroscopy) technique. After plasma treatment the values of contact angles decreased which is particularly evident for polar liquids. Apparent surface free energy increased compared to that of untreated samples. Changes of energy value are due to the electron-donor parameter of energy. This parameter increases as a result of adding polar groups at the time of surface plasma activation. Changes of surface properties are combination of increase of polar chemical functional groups, increase on the surface, and surface roughness increase.

scholarly journals P4VP Modified Zwitterionic Polymer for the Preparation of Antifouling Functionalized Surfaces

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 706 ◽  
Author(s):  
Chaoqun Wu ◽  
Yudan Zhou ◽  
Haitao Wang ◽  
Jianhua Hu
Keyword(s):  
Photoelectron Spectroscopy ◽  
Cell Attachment ◽  
Raft Polymerization ◽  
Polymer Brush ◽  
Contact Angles ◽  
Polymerization Process ◽  
Water Contact ◽  
Zwitterionic Polymers ◽  
Ito Glass ◽  
Zwitterionic Polymer

Zwitterionic polymers are suitable for replacing poly(ethylene glycol) (PEG) polymers because of their better antifouling properties, but zwitterionic polymers have poor mechanical properties, strong water absorption, and their homopolymers should not be used directly. To solve these problems, a reversible-addition fragmentation chain transfer (RAFT) polymerization process was used to prepare copolymers comprised of zwitterionic side chains that were attached to an ITO glass substrate using spin-casting. The presence of 4-vinylpyridine (4VP) and zwitterion chains on these polymer-coated ITO surfaces was confirmed using 1H NMR, FTIR, and GPC analyses, with successful surface functionalization confirmed using water contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) studies. Changes in water contact angles and C/O ratios (XPS) analysis demonstrated that the functionalization of these polymers with β-propiolactone resulted in hydrophilic mixed 4VP/zwitterionic polymers. Protein adsorption and cell attachment assays were used to optimize the ratio of the zwitterionic component to maximize the antifouling properties of the polymer brush surface. This work demonstrated that the antifouling surface coatings could be readily prepared using a “P4VP-modified” method, that is, the functionality of P4VP to modify the prepared zwitterionic polymer. We believe these materials are likely to be useful for the preparation of biomaterials for biosensing and diagnostic applications.

scholarly journals Synthesis of amphiphilic ABA triblock oligomer via ATRP and its surface properties

2017 ◽  
Vol 95 (5) ◽  
pp. 605-611 ◽  
Author(s):  
Lei Wang ◽  
Shaoqing Wen ◽  
Zhanxiong Li
Keyword(s):  
Photoelectron Spectroscopy ◽  
Microphase Separation ◽  
Gel Permeation Chromatography ◽  
Contact Angles ◽  
Chemical Compositions ◽  
Water Contact ◽  
Force Microscopy ◽  
Atomic Force ◽  
Poly Ethylene ◽  
Magnetic Resonances

A series of novel amphiphilic ABA-type poly(tridecafluorooctylacrylate)-poly(ethylene glycol)-poly(tridecafluorooctylacrylate) (henceforth referred to as p-TDFA-PEG-p-TDFA) triblock oligomers were successfully synthesized via atom transfer radical polymerization (ATRP) using well-defined Br-PEG-Br as macroinitiator and copper as catalyst. The block oligomers were characterized by Fourier transform infrared (FTIR) spectroscopy and 1H and 19F nuclear magnetic resonances (NMR). Gel permeation chromatography (GPC) showed that the block oligomers have been obtained with narrow molecular weight distributions of 1.22–1.33. X-ray photoelectron spectroscopy (XPS) was carried out to confirm the attachment of p-TDFA-PEG-p-TDFA onto the silicon substrate, together with the chemical compositions of p-TDFA-PEG-p-TDFA. The wetabilities of the oligomer films were measured by water contact angles (CAs). Water CAs of p-TDFA-PEG-p-TDFA film were measured and their morphologies were tested by atomic force microscopy (AFM). The result showed that the CAs of the oligomer films, which possess fluoroalkyl groups assembled on the outer surface, increase after heating due to the migration of fluoroalkyl groups and the resulted microphase separation of the p-TDFA-PEG-p-TDFA.

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