			Home About us Contact

Surface Treatment (surface + treatment)

Distribution by Scientific Domains

Polymers and Materials Science	49%
Medical Sciences	22%
Physics and Astronomy	8%
Chemistry	6%
Life Sciences	5%
Engineering	5%

Distribution within Polymers and Materials Science

General & Introductory Materials Science	32%
Polymer Science & Technology General	24%
Ceramics	8%

Selected Abstracts

Anode Interfacial Tuning via Electron-Blocking/Hole-Transport Layers and Indium Tin Oxide Surface Treatment in Bulk-Heterojunction Organic Photovoltaic Cells

ADVANCED FUNCTIONAL MATERIALS, Issue 4 2010
Alexander W. Hains
Abstract The effects of anode/active layer interface modification in bulk-heterojunction organic photovoltaic (OPV) cells is investigated using poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and/or a hole-transporting/electron-blocking blend of 4,4,-bis[(p -trichlorosilylpropylphenyl)-phenylamino]biphenyl (TPDSi2) and poly[9,9-dioctylfluorene- co - N -[4-(3-methylpropyl)]-diphenylamine] (TFB) as interfacial layers (IFLs). Current,voltage data in the dark and AM1.5G light show that the TPDSi2:TFB IFL yields MDMO-PPV:PCBM OPVs with substantially increased open-circuit voltage (Voc), power conversion efficiency, and thermal stability versus devices having no IFL or PEDOT:PSS. Using PEDOT:PSS and TPDSi2:TFB together in the same cell greatly reduces dark current and produces the highest Voc (0.91,V) by combining the electron-blocking effects of both layers. ITO anode pre-treatment was investigated by X-ray photoelectron spectroscopy to understand why oxygen plasma, UV ozone, and solvent cleaning markedly affect cell response in combination with each IFL. O2 plasma and UV ozone treatment most effectively clean the ITO surface and are found most effective in preparing the surface for PEDOT:PSS deposition; UV ozone produces optimum solar cells with the TPDSi2:TFB IFL. Solvent cleaning leaves significant residual carbon contamination on the ITO and is best followed by O2 plasma or UV ozone treatment. [source]

Bonding to Zirconia Using a New Surface Treatment

JOURNAL OF PROSTHODONTICS, Issue 5 2010
Moustafa N. Aboushelib DDS
Abstract Purpose: Selective infiltration etching (SIE) is a newly developed surface treatment used to modify the surface of zirconia-based materials, rendering them ready for bonding to resin cements. The aim of this study was to evaluate the zirconia/resin bond strength and durability using the proposed technique. Materials and Methods: Fifty-four zirconia discs were fabricated and divided into three groups (n = 18) according to their surface treatment: as-sintered surface (control group), airborne-particle abrasion (50-,m aluminum oxide), and SIE group. The zirconia discs were bonded to preaged composite resin discs using a light-polymerized adhesive resin (Panavia F 2.0). The zirconia/resin bond strength was evaluated using microtensile bond strength test (MTBS), and the test was repeated after each of the following intervals of accelerated artificial aging (AA): thermocycling (10,000 cycles between 5 and 55°C), 4 weeks of water storage (37°C), and finally 26 weeks of water storage (37°C). Silver nitrate nanoleakage analysis was used to assess the quality of zirconia/resin interface. A repeated measures ANOVA and Bonferroni post hoc test were used to analyze the data (n = 18, ,= 0.05) Results: There were significant differences in the MTBS values between the three test groups at each of the test intervals (p < 0.001). AA resulted in reduction in the bond strength of the as-sintered and the particle-abraded groups (5.9 MPa and 27.4, MPa, respectively). Reduction in the bond strength of these groups was explained by the observed nanoleakage across the zirconia/resin interface. The bond strength of the SIE specimens was stable after completion of AA (51.9 MPa), which also demonstrated a good seal against silver nitrate penetration across the zirconia/resin interface. Conclusion: SIE established a strong, stable, and durable bond to zirconia substrates. Conservative resin-bonded zirconia restorations are now possible using this new technique. [source]

Effect of Net Fiber Reinforcement Surface Treatment on Soft Denture Liner Retention and Longevity

JOURNAL OF PROSTHODONTICS, Issue 4 2010
MPhil, Muhanad M. Hatamleh BSc
Abstract Purpose: To evaluate shear bond strength of Molloplast-B soft liner attached to different acrylic surfaces (smooth, rough, and Sticktech net fiber-reinforced interfaces) after 3000 thermal cycles. Materials and Methods: Sixty-nine specimens were fabricated by attaching Molloplast-B soft liner to acrylic bases of three interfaces (n= 23); smooth (Group 1, control), rough (Group 2), and Sticktech net fiber-reinforced interface (Group 3). The specimens underwent 3000 thermocycles (5 and 55°C) before being subject to a shear bond test at 2 mm/min crosshead speed. Debonding sites were investigated using an optical microscope at 40× magnification. Bond failures were categorized as adhesive, cohesive, or mixed. Results: Mean (SD) bond strength values (MPa) were: 0.71 (0.15); 0.63 (0.07); and 0.83 (0.12) for smooth, rough, and fiber-reinforced acrylic interfaces, respectively. The mean values were analyzed using one-way ANOVA and Bonferroni post hoc test for pairwise comparisons (p, 0.05). The net fiber-reinforced acrylic interface exhibited a statistically significantly higher bond strength value when compared to smooth and rough acrylic interfaces (P= 0.003 and P= 0.000, respectively). Modes of failure were mainly cohesive (91%), followed by mixed failures (9%). Conclusions: Molloplast-B exhibited a stronger bond to StickTech Net fiber-reinforced surfaces when compared to smooth and rough acrylic interfaces after thermocycling. This may enhance prosthesis serviceability during clinical use. [source]

Surface Treatment of Templates for Fabrication of Reticulated Porous Ceramics

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2007
Xi-peng Pu
Before impregnation of the organic templates with an aqueous ceramic slurry, the templates were treated using silica sol. The surface morphology, elasticity of the templates, and the solid loading were studied. After the treatment, the coherence between the template and the slurry was significantly optimized, and the surfaces of the templates were uniformly covered by slurry. The elasticity of the templates was also increased. Consequently, the loading content increased considerably. [source]

Generation of Thin Surface Plasma Layers for Atmospheric-Pressure Surface Treatments

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2004
ernák
Abstract Thin layers of atmospheric-pressure non-equilibrium plasma can be generated by pulse surface corona discharges and surface barrier discharges developing on the treated surfaces or brought into a close contact with the treated surfaces. Plasma sources based on these discharge types have the potential of meeting the basic on-line production requirements in the industry and can be useful for a wide range of surface treatments and deposition processes including continuous treatment of textiles. Comparing with atmospheric pressure glow discharge sources, the potential advantages of these plasma sources include their simplicity, robustness, and capability to process in a wide range of working gases. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Cell Proliferation of Human Fibroblasts on Alumina and Hydroxyapatite-Based Ceramics with Different Surface Treatments,

INTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 2 2010
Juliana Marchi
Biocompatibility is an important characteristic of dental implant material, and in vitro tests are required to elucidate the interaction between these materials and human tissues. Cell proliferation assays were done with fibroblasts plated on the surface of alumina and hydroxyapatite sintered samples, each with a different surface treatment (sintered, rectified, or polished). After 1, 2, and three days, the samples were prepared for scanning electron microscopy observations. The data were compared by analysis of variance followed by Tukey's test. It was concluded that neither the hydroxyapatite or alumina substrate is cytotoxic, and hydroxyapatite is more biocompatible than alumina. [source]

Antiadhesion Surface Treatments of Molds for High-Resolution Unconventional Lithography,

ADVANCED MATERIALS, Issue 23 2006
J. Lee
A new strategy to achieve antiadhesion surface coatings is introduced. The approach, which uses molds coated in a thin film of poly(dimethylsiloxane) (PDMS, see figure) to achieve the antiadhesive surfaces, is applicable to virtually any type of mold material due to the use of silane chemistry and the low surface energy of PDMS. This allows simple and rapid replication of high complexity, high-aspect-ratio nanostructures with excellent replication fidelity. [source]

Large Bore Catheters with Surface Treatments versus Untreated Catheters for Vascular Access in Hemodialysis

ARTIFICIAL ORGANS, Issue 7 2004
Rolf Bambauer
Abstract:, Infection, thrombosis, and stenosis are among the most frequent complications associated with blood-contacting catheters. Complications resulting from infection remain a major problem for hemodialysis catheters, with significant numbers of catheters being removed due to catheter-related sepsis. Numerous strategies have been employed to reduce the occurrence of infection and im-prove long-term outcomes, with varying degrees of success. The most important is the careful and sterile handling by the attending staff of the catheters during hemodialysis treatments to minimize or stop a microbial colonization of the skin and the catheter. Another approach is coating the external surface of the catheters with substances which are antibacterial like silver and/or substances with low thrombogenicity like silicone. This investigation reviews results of animal and clinical experiments conducted to assess the efficacy and biocompatibility of silver and silicone coated dialysis catheters. It is concluded that silver coatings can reduce bacterial colonization and occurrence of infection associated with these devices. The catheters employing ion implantation of silicone rubber showed low thrombogenicity. Results of the studies indicate that ion beam based processes can be used to improve thrombus and infection resistance of blood contacting catheters. A new development is the microdomain structured surface (PUR-SMA coated catheters). Preliminary results with these catheters are very encouraging. [source]

INFLUENCE OF WASHING TREATMENT ON NATIVE MICROFLORA AND ESCHERICHIA COLI POPULATION OF INOCULATED CANTALOUPES

JOURNAL OF FOOD SAFETY, Issue 1 2001
DIKE O. UKUKU
ABSTRACT The influence of chlorine or hydrogen peroxide treatment on populations of Escherichia coli 25922 on the external surface of inoculated cantaloupe was investigated. Surface treatment with 70% EtOH, followed by immersion in 108 CFU/mL E. coli inoculum deposited an average of 4.4 log10CFU/cm2 cell population on the cantaloupe surface. The efficncy of washing inoculated cantaloupe was dependent on storage interval between inoculation and treatment. Dipping the cantaloupes in solutions containing 1000 mg/L chlorine or 5% peroxide for 5 min, within 24 h of inoculation, caused a 2 log10 CFU/cm2 reduction of the indigenous surface microflora and a 3,4.0 log10 CFU/cm2 reduction in E. coli. The efficacy was less when the interval between inoculation and treatment exceeded 24 h. Chlorine appeared in be a better antimicrobial agent than hydrogen peroxide against F. coli ATCC 25922 inoculated on cantaloupe surfaces while hydrogen peroxide was better in reducing surface microflora of cantaloupe. [source]

Effects of methoxyfenozide on Lobesia botrana Den & Schiff (Lepidoptera: Tortricidae) egg, larval and adult stages

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 11 2005
Francisco-Javier Sáenz-de-Cabezón Irigaray
Abstract The effect of the non-steroidal ecdysone agonist methoxyfenozide was evaluated against different developmental stages of the grape berry moth, Lobesia botrana Dennis & Schiffermuller (Lep, Tortricidae). Methoxyfenozide administered orally reduced the fecundity and fertility of adults treated with 1, 5 and 10 mg litre,1; longevity was not affected. An LC50 value of 4.5 mg litre,1 was obtained when applied to eggs of less than 1 day old. Surface treatment was more effective than when applied by spraying. Administered into the diet, methoxyfenozide had a larvicidal effect; older larvae were more susceptible than younger larvae, with LC50 values of 0.1 mg litre,1 for L1, 0.04 for L3 and 0.02 for L5. Larvae treated with sub-lethal doses throughout their lives did not emerge as adults at the highest doses (0.08, 0.04, 0.02 and 0.01 mg litre,1), with 65% and 40% emergence occurring for the lowest (0.005 and 0.0025 mg litre,1). Mortality occurred only in the larval stage. Copyright © 2005 Society of Chemical Industry [source]

Surface treatment of GaN and InN using (NH4)2Sx

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003
T. Maruyama
Abstract The effects of (NH4)2Sx treatment on GaN and InN surfaces were investigated by X-ray photoelectron spectroscopy. It was found that native oxide layers were removed from nitride surfaces by HCl and (NH4)2Sx treatments and that S-terminated surface layers were formed. In addition, the S-terminated layer on the GaN surface was removed by H* irradiation. The usefulness of the combination of (NH4)2Sx treatment and post H* irradiation was shown. [source]

New composites with high thermal conductivity and low dielectric constant for microelectronic packaging

POLYMER COMPOSITES, Issue 2 2010
Wei Ling
Three composites based on cyanate (CE) resin, aluminum nitride (AlN), surface-treated aluminum nitride [AlN(KH560)], and silicon dioxide (SiO2) for microelectronic packaging, coded as AlN/CE, AlN(KH560)-SiO2(KH560)/CE, and AlN-SiO2/CE composite, respectively, were developed for the first time. The thermal conductivity and dielectric constant of all composites were investigated in detail. Results show that properties of fillers in composites have great influence on the thermal conductivity and dielectric constant of composites. Surface treatment of fillers is beneficial to increase the thermal conductivity or reduce dielectric constant of the composites. Comparing with binary composite, when the filler content is high, ternary composites possess lower thermal conductivity and dielectric constant. The reasons leading to these outcomes are discussed intensively. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers [source]

Surface treatments of indium-tin oxide substrates for polymer electroluminescent devices

PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 15 2006
Z. Y. Zhong
Abstract In this work, three different sets of processing techniques (wet, dry, and combined treatments) were utilized to modify the surfaces of indium-tin oxide (ITO) substrates for polymer electroluminescent devices (PELDs), and the influence of surface treatments on the surface properties of ITO substrates were investigated by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), contact angle, and four-point probe. The surface energies of ITO substrates were also calculated from the measured contact angles. Experimental results show that the surface properties of the ITO substrates strongly depend on the surface treatments. Oxygen plasma treatment effectively improves the ITO surface properties since plasma decreases the surface roughness and sheet resistance, improves the surface stoichiometry and wetting. Furthermore, the PELDs with the differently treated ITO substrates as hole-injecting electrodes were fabricated and characterized. We observe that the optical and electrical characteristics of devices are greatly influenced by the surface treatments on ITO substrates. Oxygen plasma treatment decreases turn-on voltage, increases brightness and efficiency, and thereby improves the device performance of PELDs. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Effect of root surface treatment with propolis and fluoride in delayed tooth replantation in rats

DENTAL TRAUMATOLOGY, Issue 6 2008
Jéssica Lemos Gulinelli
Nevertheless, an extended extraoral period damages the periodontal ligament and results in external root resorption. The purpose of this study was to assess by histologic and histometric analysis, the influence of propolis 15% (natural resinous substance collected by Apis mellifera bees from various plants) and the fluoride solution used as root surface treatment on the healing process after delayed tooth replantation. Thirty Wistar (Rattus norvegicus albinus) rats were submitted to extraction of their upper right incisor. The teeth were maintained in a dry environment for 60 min. After this, the pulp was extirpated and the papilla, enamel organ and periodontal ligament were removed with scalpel. The teeth were divided into three experimental groups: Group I , teeth immersed in 20 ml of physiologic saline; Group II , teeth immersed in 20 ml of 2% acidulated phosphate sodium fluoride; Group III , teeth immersed in 20 ml of 15% propolis. After 10 min of immersion in the solutions, the root canals were dried and filled with calcium hydroxide paste and the teeth were replanted. The animals were euthanized 60 days after replantation. The results showed that similar external root resorption was seen in the propolis and fluoride groups. Teeth treated with physiologic saline tended to have more inflammatory root resorption compared with those treated with fluoride or propolis. However, the comparative analysis did not reveal statistically significant differences (P > 0.05) between the treatment modalities when used for delayed tooth replantation. [source]

Mechanical removal of necrotic periodontal ligament by either Robinson bristle brush with pumice or scalpel blade.

DENTAL TRAUMATOLOGY, Issue 6 2007
Histomorphometric analysis, scanning electron microscopy
Abstract,,, One of the important factors accounting for successful delayed replantation of avulsed teeth is seemingly the type of root surface treatment. Removal of necrotic cemental periodontal ligament remnants may prevent the occurrence of external root resorption, which is the major cause of loss of teeth replanted in such conditions. The purpose of this study was to compare the efficacy of two mechanical techniques for removal of root-adhered periodontal ligament. Preservation or removal of the cementum layer concomitantly with these procedures was also assessed. Forty-five roots of healthy premolars extracted for orthodontic purposes were selected. After extraction, the teeth were kept dry at room temperature for 1 h and then immersed in saline for rehydration for an additional 10 min. Thereafter, the roots were assigned to three groups, as follows: group 1 (control) - the cemental periodontal ligament was preserved; group 2 - removal of the periodontal ligament by scraping root surface with a scalpel blade (SBS); group 3 - periodontal ligament remnants were removed using a Robinson bristle brush at low-speed with pumice/water slurry (RBP). The specimens were analysed histomorphometrically and examined by scanning electron microscopy. The quantitative and qualitative analyses of the results showed that the RBP technique was significantly more effective than the SBS technique for removal of the periodontal ligament remnants adhered to root surface. Both techniques preserved the cementum layer. [source]

Evaluation of Thin Film Titanium Nitride Electrodes for Electroanalytical Applications

ELECTROANALYSIS, Issue 10 2007
Carolina Nunes, Kirchner
Abstract Titanium nitride is a hard and inert conducting material that has yet not been widely used as electrode material for electroanalytical applications although there are highly developed protocols available to produce well adherent micro and nanostructured electrodes. In this paper the possibilities of using titanium nitride thin films for electroanalytical applications is investigated. Scanning electrochemical microscope (SECM) was used for analysis of the redox kinetics of a selected fast redox couple at thin films of titanium nitride (TiN) in different thicknesses. The investigation was carried out by approaching an amperometric ultramicroelectrode (UME) to the TiN film while the soluble redox couple (ferrocenemethanol/ferrociniummethanol) served as mediator in a SECM configuration. The substrate was biased at a potential so that it rereduces the species being produced at the UME, thus controlling the feedback effect. Normalized current,distance curves were fitted to the theoretical model in order to find the apparent heterogeneous standard rate constant (k°) at the sample. The data are further supported by structural investigation of the TiN films using scanning force microscopy and X-ray photoelectron spectroscopy. It was found that the kinetics are little influenced by prolonged storage in air. The heterogeneous standard rate constants in 2,mM ferrocenemethanol were (0.73±0.05)×10,3,cm s,1 for 20,nm TiN thin layer, (1.5±0.2)×10,3,cm s,1 for 100,nm TiN thin layer and (1.3±0.2)×10,3,cm s,1 for 300,nm TiN thin layer after prolonged storage in air. Oxidative surface treatment (in order to remove organic adsorbates) decreased the kinetics in agreement with a thicker oxide layer on the material. The results suggest that their direct use for amperometric detection of reversible redox systems in particular at miniaturized configurations may be advantageous. [source]

Electrokinetic instability effects in microchannels with and without nanofilm coatings

ELECTROPHORESIS, Issue 24 2008
Lung-Ming Fu
Abstract This paper presents a parametric experimental investigation into the electrokinetic instability (EKI) phenomenon within three different types of microfluidic device, namely T-type, cross-shaped, and cross-form with an expansion configuration. The critical electric field strength at which the EKI phenomenon is induced is examined as a function of the conductivity ratio, the microchannel width, the expansion ratio, and the surface treatment of the microchannel walls. It is found that the critical electric field strength associated with the onset of EKI is strongly dependent on the conductivity ratio of the two samples within the microfluidic device and reduces as the channel width increases. The surfaces of the microchannel walls are coated with hydrophilic or hydrophobic organic-based spin-on-glass (SOG) nanofilms for glass-based microchips. The experimental results indicate that no significant difference exists in the critical electric field strengths in the hydrophilic or hydrophobic SOG-coated microchannels, respectively. However, for a given conductivity ratio and microchannel width, the critical strength of the electric field is slightly lower in the SOG-coated microchannels than in the non-coated channels. In general, the results presented in this study demonstrate the potential for designing and controlling on-chip assays requiring the manipulation of samples with high conductivity gradients, and provide a useful general reference for avoiding EKI effects in capillary electrophoresis analysis applications. [source]

A parylene-based dual channel micro-electrophoresis system for rapid mutation detection via heteroduplex analysis,

ELECTROPHORESIS, Issue 18 2008
Sertan Sukas
Abstract A new dual channel micro-electrophoresis system for rapid mutation detection based on heteroduplex analysis was designed and implemented. Mutation detection was successfully achieved in a total separation length of 250,,m in less than 3,min for a 590,bp DNA sample harboring a 3,bp mutation causing an amino acid change. Parylene-C was used as the structural material for fabricating the micro-channels as it provides conformal deposition, transparency, biocompatibility, and low background fluorescence without any surface treatment. A new dual channel architecture was derived from the traditional cross-channel layout by forming two identical channels with independent sample loading and waste reservoirs. The control of injected sample volume was accomplished by a new u-turn injection technique with pull-back method. The use of heteroduplex analysis as a mutation detection method on a cross-linked polyacrylamide medium provided accurate mutation detection in an extremely short length and time. The presence of two channels on the microchip offers the opportunity of comparing the sample to be tested with a desired control sample rapidly, which is very critical for the accuracy and reliability of the mutation analyses, especially for clinical and research purposes. [source]

Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration

EUROPEAN JOURNAL OF ORAL SCIENCES, Issue 5 2010
Andy C. Ritts
Ritts AC, Li H, Yu Q, Xu C, Yao X, Hong L, Wang Y. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration. Eur J Oral Sci 2010; 118: 510,516. © 2010 Eur J Oral Sci The objective of this study was to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces used for composite restoration. Extracted unerupted human third molars were prepared by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated using a non-thermal atmospheric argon plasma brush for various periods of time. The molecular changes of the dentin surfaces were analyzed using Fourier transform infrared spectrophotometry/attenuated total reflectance (FTIR/ATR), and an increase in the amount of carbonyl groups was detected on plasma-treated dentin surfaces. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars and analyzed using tensile testing. Student,Newman,Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s of plasma treatment. However, the bonding strength to plasma-treated inner dentin did not show any improvement. It was found that plasma treatment of the peripheral dentin surface for up to 100 s resulted in an increase in the interfacial bonding strength, while prolonged plasma treatment of dentin surfaces (e.g. 5 min) resulted in a decrease in the interfacial bonding strength. [source]

Silver Surface Iodination for Enhancing the Conductivity of Conductive Composites

ADVANCED FUNCTIONAL MATERIALS, Issue 16 2010
Cheng Yang
Abstract The electrical conductivity of a silver microflake-filled conductive composites is dramatically improved after a filler surface treatment. By a simple iodine solution treatment, nonstoichiometric silver/silver iodide nanoislands form on the silver filler surface. Evidence of the decrease of surface silver oxide species is provided by TOF-SIMS and the redox property of the nanoclusters is studied using cyclic voltammetry and TOF-SIMS depth profile analyses. The redox property of the nanoclusters on silver flakes helps enhance the electrical conductivity of the conductive composites. The electrical resistivity of the improved conductive composites is measured by four-point probe method; the reliability of the printed thin film resistors is evaluated by both the 85 °C/85% relative humidity moisture exposure and the ,40 , 125 °C thermal cycling exposure. The conductive composite printed radio frequency identification (RFID) antennas with 27.5 wt% of the modified silver flake content show comparable performance in the RFID tag read range versus copper foil antennas, and better than those commercial conductive adhesives that require much higher silver content (i.e., 80 wt%). This work suggests that a surface chemistry method can significantly reduce the percolation threshold of the loading level of the silver flakes and improve the electrical conductivity of an important printed electronic passive component. [source]

Silver Surface Iodination for Enhancing the Conductivity of Conductive Composites

Effect of reline material and denture base surface treatment on the impact strength of a denture base acrylic resin

GERODONTOLOGY, Issue 1 2010
Luciano Elias Da Cruz Perez
doi:10.1111/j.1741-2358.2009.00292.x Effect of reline material and denture base surface treatment on the impact strength of a denture base acrylic resin Objective:, In this study, the effect of relining and surface treatment on the impact strength (IS) of a heat-polymerising denture base acrylic resin (Lucitone 550-L) was evaluated. Materials and methods:, Rectangular bars of L were made (60 × 6 × 2 mm) and relined (2 mm) with the relining resins Ufi Gel Hard (UH) and Tokuso Rebase Fast (TR). Specimens relined with L and intact L, TR and UH specimens were also made (60 × 6 × 4 mm), for comparison. Before relining, the L surface was left untreated or wetted with methyl methacrylate monomer and/or the bonding agents (BA) supplied by manufacturers of the reline resins. V-notches were machined at the midpoint of the length of all specimens. The notches were made either across the width (Nw) or across the thickness of the specimens (Nth). The Charpy impact test was performed using a 0.5-J pendulum, which had been specially designed and constructed. Data were analysed separately for each notch position using one-way analysis of variance and Tukey honestly significant difference post - hoc test (p = 0.05). Results:, The IS of L was similar to that of L/L. For the Nw notch, treating the denture base L with TR BA and relining with TR reline material produced the highest IS. Conclusion:, The IS of specimens made from heat polymerising acrylic resin Lucitone 550 was increased after relining using the hard chairside reline resin TR with its proprietary BA. [source]

Orders-of-Magnitude Reduction of the Contact Resistance in Short-Channel Hot Embossed Organic Thin Film Transistors by Oxidative Treatment of Au-Electrodes,

ADVANCED FUNCTIONAL MATERIALS, Issue 15 2007
B. Stadlober
Abstract In this study we report on the optimization of the contact resistance by surface treatment in short-channel bottom-contact OTFTs based on pentacene as semiconductor and SiO2 as gate dielectric. The devices have been fabricated by means of nanoimprint lithography with channel lengths in the range of 0.3,,m,<,L,<,3.0,,m. In order to reduce the contact resistance the Au source- and drain-contacts were subjected to a special UV/ozone treatment, which induced the formation of a thin AuOx layer. It turned out, that the treatment is very effective (i),in decreasing the hole-injection barrier between Au and pentacene and (ii),in improving the morphology of pentacene on top of the Au contacts and thus reducing the access resistance of carriers to the channel. Contact resistance values as low as 80,,,cm were achieved for gate voltages well above the threshold. In devices with untreated contacts, the charge carrier mobility shows a power-law dependence on the channel length, which is closely related to the contact resistance and to the grain-size of the pentacene crystallites. Devices with UV/ozone treated contacts of very low resistance, however, exhibit a charge carrier mobility in the range of 0.3,cm2,V,1,s,1,<,,,<,0.4,cm2,V,1,s,1 independent of the channel length. [source]

Microfluidics: Surface-Treatment-Induced Three-Dimensional Capillary Morphogenesis in a Microfluidic Platform (Adv. Mater.

ADVANCED MATERIALS, Issue 47 2009
47/2009)
The cover shows confocal images of 3D sprouting into matrix material in microfluidic channels. Roger Kamm and co-workers report on p. 4863 that robust induction of realistic angiogenesis into the 3D matrix material under simultaneous imaging and a stably controlled concentration gradient of chemoattractants can be achieved. The formation of a 3D vascular network is demonstrated to be a direct consequence of surface treatment of the region of the device-containing matrix material. [source]

Surface-Treatment-Induced Three-Dimensional Capillary Morphogenesis in a Microfluidic Platform

ADVANCED MATERIALS, Issue 47 2009
Seok Chung
Robust induction of realistic angiogenesis into a 3D matrix material under simultaneous imaging and a stably controlled concentration gradient of chemoattractants is presented. The formation of a 3D vascular network is demonstrated to be a direct consequence of surface treatment of the region of the device-containing matrix material. [source]

Cell Proliferation of Human Fibroblasts on Alumina and Hydroxyapatite-Based Ceramics with Different Surface Treatments,

Improved Stirling engine performance through displacer surface treatment

INTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 3 2010
Halit Karabulut
Abstract This study intended to improve the performance of the beta-type Stirling engine, being developed by the authors for solar energy and low-grade heat sources, by means of displacer surface treatments. Three different displacers were manufactured and tested where one of them was without any surface treatment, other was zirconium coated with 0.15,mm thickness, and the other was helically knurled with 0.30,mm track depth. Because of good thermo-physical properties, helium was used as the working fluid. The heat was supplied by an LPG burner. Tests were conducted at 360±10°C hot end temperature. The highest engine power was obtained with knurled displacer as 250,W at 545,rpm speed and corresponding to this power 4.38,Nm torque was obtained. This was followed by coated and smooth displacers. Power increments provided by the knurled displacer are 40 and 60% compared with the zirconium-coated and untreated displacers. Increments of knurled displacer's torque compared with that of coated and untreated displacers are 13 and 30%, respectively. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Self-Assembled Silica Photonic Crystal as a Liquid-Crystal Alignment Layer and its Electro-optic Applications in Fabry,Perot Cavity Structures,

ADVANCED MATERIALS, Issue 19 2004
Y. Ha
Microgrooves on self-assembled photonic-crystal (PC) films align liquid crystals (LCs) without any additional rubbing or surface treatment. Nematic (see Figure and inside cover) or twisted-nematic LCs can be formed, depending on the relative orientation of the microgrooved films. A LC Fabry,Perot (FP) cavity was fabricated using these PC films, and electro-optic tuning of FP cavity modes is demonstrated. [source]

Adhesion of Staphylococcus aureus and Staphylococcus epidermidis to the Episkin® reconstructed epidermis model and to an inert 304 stainless steel substrate

JOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2004
G. Lerebour
Abstract Aims:, The aim of this study was to evaluate the respective influence of the physicochemical interactions and the roughness involved in the first part of the biological substrate biocontamination. Methods and Results:, Therefore we compared the bioadhesion results obtained on the biological model substrate (Episkin®) and on a commonly employed inert substrate (AISI 304 stainless steel), frequently used either in dermatology or in development of medical devices. The two studied strains presented different characteristics, both physicochemical and microbiological. Staphylococcus epidermidis, a relatively hydrophobic bacteria capable of exchanging interactions which are principally of the van der Waals type, adhered more to 304 steel than to the surface of reconstituted skin. As for S. aureus, an essentially basic, hydrophilic bacteria, was more adherent to Episkin® (a bipolar, hydrophilic substrate) than to stainless steel (a unipolar, basic, hydrophilic substrate). Conclusions:, In the absence of electrostatic interactions, the adhesion of substrate-dependent bacteria to the surface of reconstituted skin was dependent upon the balance between ,LW, ,+ and ,,. Significance and Impact of the Study:, Consequently, so as to restrict microbial adhesion and reduce adhesive binding between micro-organisms and the surface of the skin, it would be preferable to render this substrate hydrophobic and apolar through the use of appropriate surface treatment. [source]

Calcium-phosphate surface coating by casting to improve bioactivity of titanium

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 5 2001
Taiji Sohmura
Abstract In order to improve the bioactivity of titanium, an original surface treatment was attempted with the use of a casting technique was attempted. Pure titanium was cast into a special graphite mold in which the cavity wall was coated with hydroxyapatite (HA) powder. According to analyses of X-ray diffraction and EDX, the existence of HA and CaO and uptake of Ca and P on the surface of the titanium castings were identified. By immersing the specimen in Hank's solution, the concentrations of Ca and P on the surface increased with immersion time, and the formation of a thin layer with characteristics of spherical HA precipitates was observed after 1 week. The concentrations of Ca and P elements and the Ca/P ratio on the HA layer increased with immersion time. The formation of the HA layer on the titanium cast by this treatment was significantly accelerated compared with pure titanium. The present surface treatment of Ti is expected to improve early bone fixation of Ti implants. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res (Appl Biomater) 58: 478,485, 2001 [source]