Surface Modification Of Glass Research Articles

Structural and compositional modification of a barium boroaluminosilicate glass surface by thermal poling

In addition to inducing second-order nonlinear properties, significant structural and compositional alteration can be imparted to glass surfaces during the process of thermal poling. In this work, we focus on how thermal poling affects a structurally complex, nominally alkali-free boroaluminosilicate display glass composition. We provide evidence for electrolysis of the glass network, characterized by the migration of both cations (Ba2+, Na+) and anions (O−, F−) towards opposing electrode interfaces. This process results in oxidation of the positively biased electrode and forms a network-former rich, modifier-depleted glass surface layer adjacent to the anodic interface. The modified glass layer thickness is qualitatively correlated to the oxidation resistance of the electrode material, while extrinsic ions such as H+/H3O+ at not found in the depletion layer to compensate for the migration of modifier cations out of the region. Rather, FTIR spectroscopy suggests a local restructuring of the B2O3–Al2O3–SiO2 network species to accommodate the charge imbalance created by the exodus of network-modifying cations, specifically the conversion of tetrahedral B(4) to trigonal B(3) as Ba or Na ions are removed from B-related sites in the parent network. The resultant poling-induced depletion layer exhibits enhanced hydrolytic resistance under acidic conditions, and the IR spectra are substantially unlike those produced by acid leaching the same glass.

Surface modification and bio-activation of bio-inert glasses through thermal oxidation

Bioactivity and bio-compatibility are inversely related to the mechanical and chemical stability of bio-glass. In this research, we suggest a new method of conferring bio-activity on bio-inert glass through the addition of a small amount of FeO and oxidizing annealing, that is, surface modification, without degrading mechanical and chemical durability. The surface of iron-bearing bio-inert glasses can be successfully modified to form a Na2O-rich and SiO2-depletion layer on the surface, which allows the bio-activation sites to form and grow hydroxycarbonate apatite (HCA) crystals. After immersion in a solution of simulated body fluid (SBF) the surfaces show the formation of HCA and silica gel layers. We suggest that glasses with 2.30≤network connectivity (NC)≤2.61 and up to Na2O/CaO=1.25 can be modified into a bio-active surface by heat-treatment in an oxidizing atmosphere near the glass transition temperature. The reaction of the modified surface with SBF followed a process similar to typical bioactive glass. The thickness of the HCA surface layer after immersion in SBF for 7days increased with a decrease in the Na2O/CaO ratio of the mother glasses. Inducing a bio-activity to bio-inert glasses with a high SiO2 content and good mechanical and chemical durability through thermal oxidation is a new method to produce a bio-active glass.

Clickable poly(ionic liquid)s for modification of glass and silicon surfaces

Covalent attachment of poly(ionic liquid)s (PILs) by click chemistry on glass or silicon (Si) surfaces was performed. Poly[1-(4-vinylbenzyl)-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] (polyVBBI+Tf2N−), and copolymers of polyVBBI+Tf2N− with fluorescein O-methacrylate were synthesized by conducting an atom transfer radical polymerization (ATRP) from initiators containing azide or thioacetate groups. The azide- and thiol-terminated PILs were then successfully grafted onto alkyne and alkene modified glass/Si wafers by thermal azide–alkyne cycloaddition and photoinitiated thiol-ene click reactions, respectively. The modified surfaces were characterized by contact angle measurements and ellipsometry. The fluorescent PIL functionalized surfaces showed strong fluorescence under UV irradiation. This procedure of tethering PILs to substrates also provides an easy way to change the surface hydrophilicity by replacing the anions in the grafted PILs. The present approach could be readily applied for surface modifications with other types of PILs or their copolymers to achieve different functionalities on various surfaces.

Effect of the type of fluorofunctional organosilicon compounds and the method of their application onto the surface on its hydrophobic properties

Different fluorofunctional organosilicon compounds were used for glass surface modification and the influence of their structure on the surface hydrophobic properties was investigated.

Adhesion enhancement for liquid silicone rubber and different surface by organosilane and Pt catalyst at room temperature

Surface modification of aluminum, glass, epoxy resin, polypropylene and polyethylene via corona discharge pretreatment and platinum catalyst addition to promote their adhesion with liquid silicone rubber is reported. The corona-pretreated substrate surface was silanized with vinyltrimethoxysilane to generate vinyl groups on the surface, which could be initiated by platinum catalyst to form vinyl radicals. Then, the vinyltrimethoxysilane modified substrate was dipped into platinum catalyst solution to introduce platinum on the vinyltrimethoxysilane surface. The modified aluminum surface was characterized by X-ray photoelectron spectroscopy (XPS). The strong adhesion property between liquid silicone rubber and different surface was achieved by introducing a small amount of vinyltrimethoxysilane and platinum catalyst, followed by curing at low temperature. XPS result indicated the formation of vinyltrimethoxysilane coating on aluminum surface. Peel strength for liquid silicone rubber/vinyltrimethoxysilane–platinum surface was over 3·2 kN/m compared to only 1·1 kN/m for liquid silicone rubber/vinyltrimethoxysilane–aluminum. The cohesive failure in the bulk of liquid silicone rubber was observed for liquid silicone rubber/vinyltrimethoxysilane–platinum surface. It is assumed that the cross-linking reactions between vinyl groups in the vinyltrimethoxysilane coating and unsaturated terminal group of liquid silicone rubber occur due to the existence of platinum catalyst.

Preparation and properties of fluorinated carboxylic acid/silica nanocomposite-encapsulated low molecular weight compounds

Perfluoro-2-methyl-3-oxahexanoic acid/silica nanocomposites [RF-CO2H/SiO2] were prepared by the sol–gel reaction of tetraethoxysilane in the presence of silica nanoparticles and the corresponding fluorinated carboxylic acid under alkaline conditions. RF-CO2H/SiO2 nanocomposites were found to exhibit no weight loss in proportion to the contents of fluorinated carboxylic acid in the composites even after calcination at 800 °C. The modified glass surface treated with the RF-CO2H/SiO2 nanocomposites was shown to give a good oleophobicity with superhydrophilicity imparted by fluorinated carboxylic acid in the composites. RF-CO2H/SiO2 nanocomposites were also applied to the encapsulation of a variety of low molecular weight aromatic and aliphatic compounds such as bisphenol AF [BPAF], bisphenol A [BPA], 4,4′-biphenol [BPOH], octafluoro-4,4′-biphenol [FBPOH], 4,4′-bis(triethoxysilyl)-1,1′-biphenyl [BTSBP], 3-(trihydroxysilyl)propane-1-sulfonic acid [THSP], α-cyclodextrin (α-CD), β-cyclodextrin (β-CD), and γ-cyclodextrin (γ-CD). Encapsulated aromatic compounds possessing acidic hydroxyl groups such as BPAF, BPA, and FBPOH in the RF-COOH/SiO2 nanocomposites were found to exhibit no weight loss corresponding to the contents of aromatic compounds in the composites even after calcination at 800 °C. On the other hand, encapsulated aromatic compounds possessing no acidic hydroxyl groups such as BTSBP and aliphatic compounds (THSP, α-, β-, and γ-CD) gave a clear weight loss corresponding to the contents of these compounds in the composites after calcination. In addition, the fluorinated silica nanocomposite-encapsulated these compounds were applied to the surface modification of glass to exhibit a good oleophobicity with superhydrophilicity imparted by fluorinated carboxylic acid on the surface.

Durable contact active antimicrobial materials formed by a one-step covalent modification of polyvinyl alcohol, cellulose and glass surfaces

In this work we have applied a direct covalent linkage of quaternary ammonium salts (QAS) to prepare a series of contact active antimicrobial surfaces based on widely utilized materials. Formation of antimicrobial polyvinyl alcohol (PVA-QAS), cellulose (cellulose-QAS) and glass (glass-QAS) surfaces was achieved by one step synthesis with no auxiliary linkers. The X-ray photoelectron spectroscopy (XPS) revealed tridentate binding mode of the antimicrobial agent. The antimicrobial activity of the prepared materials was tested on Bacillus cereus, Alicyclobacillus acidoterrestris, Escherichia coli and Pseudomonas aeruginosa. Active site density of the modified materials was examined and found to correlate with their antimicrobial activity. Stability studies at different pH values and temperatures confirmed that the linkage of the bioactive moiety to the surface is robust and resistant to a range of pH and temperatures. Prolonged long-term effectiveness of the contact active materials was demonstrated by their repeated usage, without loss of the antimicrobial efficacy.

Silane modification of glass and silica surfaces to obtain equally oil‐wet surfaces in glass‐covered silicon micromodel applications

Wettability is a key parameter influencing capillary pressures, permeabilities, fingering mechanisms, and saturations in multiphase flow processes within porous media. Glass‐covered silicon micromodels provide precise structures in which pore‐scale displacement processes can be visualized. The wettability of silicon and glass surfaces can be modified by silanization. However, similar treatments of glass and silica surfaces using the same silane do not necessarily yield the same wettability as determined by the oil‐water contact angle. In this study, surface cleaning pretreatments were investigated to determine conditions that yield oil‐wet surfaces on glass with similar wettability to silica surfaces treated with the same silane, and both air‐water and oil‐water contact angles were determined. Borosilicate glass surfaces cleaned with standard cleaning solution 1 (SC1) yield intermediate‐wet surfaces when silanized with hexamethyldisilazane (HMDS), while the same cleaning and silanization yields oil‐wet surfaces on silica. However, cleaning glass in boiling concentrated nitric acid creates a surface that can be silanized to obtain oil‐wet surfaces using HMDS. Moreover, this method is effective on glass with prior thermal treatment at an elevated temperature of 400°C. In this way, silica and glass can be silanized to obtain equally oil‐wet surfaces using HMDS. It is demonstrated that pretreatment and silanization is feasible in silicon‐silica/glass micromodels previously assembled by anodic bonding, and that the change in wettability has a significant observable effect on immiscible fluid displacements in the pore network.

Enhanced bone regeneration in rat calvarial defects implanted with surface-modified and BMP-loaded bioactive glass (13-93) scaffolds

The repair of large bone defects, such as segmental defects in the long bones of the limbs, is a challenging clinical problem. Our recent work has shown the ability to create porous scaffolds of silicate 13-93 bioactive glass by robocasting which have compressive strengths comparable to human cortical bone. The objective of this study was to evaluate the capacity of those strong porous scaffolds with a grid-like microstructure (porosity=50%; filament width=330μm; pore width=300μm) to regenerate bone in a rat calvarial defect model. Six weeks post-implantation, the amount of new bone formed within the implants was evaluated using histomorphometric analysis. The amount of new bone formed in implants composed of the as-fabricated scaffolds was 32% of the available pore space (area). Pretreating the as-fabricated scaffolds in an aqueous phosphate solution for 1, 3 and 6days to convert a surface layer to hydroxyapatite prior to implantation enhanced new bone formation to 46%, 57% and 45%, respectively. New bone formation in scaffolds pretreated for 1, 3 and 6days and loaded with bone morphogenetic protein-2 (BMP-2) (1μg per defect) was 65%, 61% and 64%, respectively. The results show that converting a surface layer of the glass to hydroxyapatite or loading the surface-treated scaffolds with BMP-2 can significantly improve the capacity of 13-93 bioactive glass scaffolds to regenerate bone in an osseous defect. Based on their mechanical properties evaluated previously and their capacity to regenerate bone found in this study, these 13-93 bioactive glass scaffolds, pretreated or loaded with BMP-2, are promising in structural bone repair.

Exploring the functionalization ratio of mesoporous silica glass with imidazolium entities on the synthesis of supported gold nanoparticles

This study describes the surface modification of porous Vycor glass® (PVG®) with ionic species based on 1-methyl-imidazolium groups, and the posterior utilization of the functional porous substrate to synthesize supported gold nanoparticles (Au NPs). The functionalization degree (amount of imidazolium groups per gram of PVG®) was successfully controlled by the concentration of the imidazolium-based alkoxysilane in the reaction media. The ion-exchange properties of the functional groups allowed an effective and homogeneous upload of AuCl4− throughout the monolithic PVG® structure, with subsequent conversion to Au NPs by thermal treatment at 823 K, which also eliminated the organic groups chemically bonded to the surface. The amount of adsorbed AuCl4− ions was shown to have influence on loading of the Au NPs while no size variation is observed, indicating that the porous environment of PVG® acts as a nanoreactor where the particles are formed in the confined space.

Coordination chemistry for antibacterial materials: a monolayer of a Cu2+ 2,2′-bipyridine complex grafted on a glass surface

A propyltrimethoxysilane-modified 2,2'-bipyridine ligand is synthesized and its acetonitrile solutions are used to prepare monolayers of the molecule on glass surfaces. Absorption and X-ray photoelectron spectroscopy demonstrate that the modified glass surfaces bind Cu(2+) with a 1:1 ratio with respect to the 2,2'-bipyridine moieties under the chosen preparative conditions, producing materials bearing 0.016 μg cm(-2) of copper. Although in trace amounts, the bound Cu(2+) cations exert a significant microbicidal effect against Escherichia coli and Staphylococcus aureus.

Main Challenges for High Performance NAS Battery: Materials and Interfaces

AbstractThe progress in the research work and real applications of sodium‐sulfur (NAS) battery in large scale energy storage is introduced. The key materials and interfaces of the battery, particularly the role of Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), are systematically reviewed. As the most important and difficult part, the high‐quality beta‐ alumina ceramic electrolyte tubes are prepared by a low‐cost solid state reaction process; their sealing performance and interfacial behavior with molten sodium and sulfur electrodes could be substantially improved by glass ceramic type sealants and surface modification, respectively. Combination of carbon and additives like SiO2 with different wetting behaviors for sulfur and the discharge product sulfides is shown to be significant in improving the electrochemical performances of NAS battery. Conductive ceramic coatings are developed as anti‐corrosion media of the current collector of sulfur electrode; this is identified as an effective route to protect the metal parts.

Effect of Surface Modification of Bioactive Glass on Properties of Poly-L-lactide Composite Materials

The 3-aminopropyltrimethoxysilane (APS) surface modification of sol-gel bioactive glass (BG) was performed to improve the phase compatibility between poly-L-lactide (PLLA) and BG. The composite based on PLLA and modified BG was fabricated by using hot pressing methods. The effects of APS modification on the morphology of BG and mechanical properties of the PLLA/BG composite were investigated. The results indicated that uniformly dispersed BG particles, without agglomeration, were obtained after surface modification. Furthermore, the bending strength, bending modulus, and shearing strength of PLLA/BG-APS composites were all higher than those of unmodified composites. However, the bending strength and shearing strength of PLLA/BG-APS composites significantly decreased with increasing BG content for all, whereas the bending modulus increased.

Static SIMS study on surfaces of chalcogenide glasses modified by an organic layer

Chalcogenide glasses are useful optic materials that find applications in infrared spectroscopy, sensors and thermal imaging. A route for direct surface modification of such glasses with organic layers has been investigated by static Time of Flight Secondary Ion Mass Spectrometry (ToF-SIMS). The GAS (germanium–arsenic–selenium) glasses are modified by deposition followed by UV-irradiation of disulfide- or/and silane-functionalized organic molecules. SIMS analysis shows the characteristic fragments of the grafted molecules and organic–inorganic fragments which prove unambiguously the binding mode to the surface: disulfides, after S–S cleavage, are linked to arsenic and selenium; triethoxysilanes bind exclusively to oxidized germanium. The successive grafting of disulfide and silane compounds on the same substrate (IG2 glass with 33% of Ge) affords a “mixed” organic layer on the glass surface. From water contact angle measurements and X-ray Photo-electron Spectroscopy (XPS), the coverage density is not significantly improved comparatively to the “non-mixed” layers. However, the grafting of both types of molecules allows to reach a more homogeneous coverage.

Surface modification of amorphous substrates by disulfide derivatives: A photo-assisted route to direct functionalization of chalcogenide glasses

A novel route for chalcogenide glass surface modification is disclosed. The formation of an organic monolayer from disulfide derivatives is studied on two different glasses of formula GexAsySez by water contact angle measurement, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy in attenuated total reflection mode (FTIR-ATR). The potential anchoring group is the disulfide functionality. Since thioctic acid derivatives absorb around 335nm, an irradiation step is included, in order to favor S–S disruption. Three types of disulfide compounds are grafted onto small glass breaks for contact angle and XPS analyses. The results show effective changes of surface state. According to contact angle measurement, the deposited organic layer functionalized by a small polyethylene glycol chain leads to a more hydrophilic surface, long alkyl chain or a perfluorinated carbon chain leads to a more hydrophobic surface. XPS shows the presence at the surface of an organic layer with sulfur and ethylene oxide chains, or augmentation of organic carbons or fluorine and CF bonds. The photo-assisted grafting of the disulfides onto an ATR prism made of chalcogenide glass shows that this surface modification process does not affect infrared transparency, despite UV treatment, and accurate structural analysis can be performed.

Creation of coating surfaces possessing superhydrophobic and superoleophobic characteristics with fluoroalkyl end-capped vinyltrimethoxysilane oligomeric nanocomposites having biphenylene segments

Fluoroalkyl end-capped vinyltrimethoxysilane oligomeric nanocomposites having biphenylene units [RF-(VM-SiO2)n-RF/Ar-SiO2] were prepared by the sol–gel reaction of the corresponding oligomer [RF-(VM)n-RF] with 4,4′-bis(triethoxysilyl)-1,1′-biphenyl [Ar-Si(OEt)3] under alkaline conditions. RF-(VM-SiO2)n-RF/Ar-SiO2 nanocomposites were applied to the surface modification of PMMA to exhibit not only a good oleophobicity imparted by fluorine but also a fluorescent emission ability on the surface. Methanol sol solutions of RF-(VM-SiO2)n-RF/Ar-SiO2 nanocomposites were effective for the surface modification of glass through the dipping technique to exhibit good oleophobicity with superhydrophobicity on the modified glass surface. On the other hand, 1,2-dichloroethane sol solutions enabled RF-(VM-SiO2)n-RF/Ar-SiO2 nanocomposites to exhibit both superhydrophobic and superoleophobic characteristics on the modified surface through dipping the glass in these sol solutions.

Plasma Beam Alignment of Liquid Crystals on the Bare Glass: Modification of Surface Chemical Composition

X-ray Photoelectron Spectroscopy was applied to study the chemical composition of the modified glass surfaces by the flux of accelerated Ar or Ar/H2 plasma in order to clarify mechanisms of liquid crystal (LC) alignment on these surfaces. It was established that the surface of prinstine glass exposed to air contains carbonaceous contamination layer consisting of about 50% of aliphatic/aromatic carbon and about 50% of C–O moieties of various types. Plasma processing results in partial ablation of this layer and modification of its chemical composition. This suggests that LCs are actually being aligned by the plasma modified carbonaceous layer rather than by a pure glass.

Surface-modified Tubular Glass Electrolyte for Portable Direct Methanol Fuel Cell

Abstract A fast-proton-conducting porous tubular glass electrolyte was prepared by surface modification of glass, and the direct methanol fuel cell performance of the glass electrolyte was measured. The glass electrolyte showed very low methanol permeability of 2.1 × 10−7 cm2 s−1 compared with the polymer electrolyte Nafion® (2.3 × 10−6 cm2 s−1). An open-circuit voltage of approximately 0.7 V was obtained at room temperature, which corresponds to 15 V when the tubes are stacked in a 6.5 cm3 portable cell.

Surface modification of silica glass by CHF 3 plasma treatment and carbon negative-ion implantation for cell pattern adhesion

We have investigated a method for the patterning of cell adhesion on a silica glass by using two-steps of surface modification processes of CHF 3 plasma treatment and negative-ion pattern implantation. For the first step, exposure of CHF 3 plasma to silica glass (SG) was used to obtain hydrophobic surface, leading to eliminate cell-adhesion property. After treatment with RF power of 20 W and exposure time of 120 s, the hydrophobicity was occurred from the increase in contact angle of SG from 43° to 88° and its reason based on XPS analysis was due to formations of C―F, C―F 2, and C―F 3 bonds, so-called fluorocarbonated bonds. Culture of mesenchymal stem cells (MSC) and rat adrenal pheochromocytoma cells (PC12h) showed the degradation of cell adhesion property on the plasma-treated SG surface. For the second step, carbon negative-ion implantation into the hydrophobic fluorocarbonated-SG surface was used to pattern the hydrophilic region, leading to enhance cell adhesion property. The contact angle of C-modified surface decreased to 76° at conditions of 15 keV and 1 × 10 15 ions/cm 2. XPS showed that the hydrophilicity was due to reduction of C―F x bonds and formation of C―O and C═O bonds. After 3 days culture of MSC and PC12h on the C-implanted surface of the plasma-treated SG, a fairly good adhesion patterning of both cells was obtained on the ion-implanted regions.

Electroless plating of copper on surface-modified glass substrate

This work focuses on developing a novel convenient method for electroless copper deposition on glass material. This method is relied on the formation of amino (NH2)-terminated film on the surface of glass substrate, by coating polyethylenimine (PEI) on glass matrix and using epichlorohydrin (ECH) as cross-linking agent. The introduced amino groups can effectively adsorb the palladium, the catalysts which could initiate the subsequent Cu electroless plating, onto the glass substrate surface. Finally, a copper film is formed on the palladium-activated glass substrate through copper electroless plating and the surface-coppered glass material is therefore acquired. X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscopy (SEM) images combined with energy diffraction X-ray (EDX) analysis demonstrate the successful copper deposition on the surface of glass substrate.