Surface Modification Of Glass Research Articles

Multifunctional hydrophobin-like protein (HFB-NJ1): A versatile solution for wastewater treatment

As wastewater contains a variety of contaminating bacteria and oily residues, there is an urgent need for environmentally safe bactericidal agents and surfactants which can be applied for wastewater treatment. The present study emphasizes on the potential of hydrophobin-like protein (HFB-NJ1) extracted from sporulating mycelia of Aspergillus sp. NJ1 for wastewater treatment. The purified HFB-NJ1, depicted the presence of one single protein band of molecular size approximately 11–12 kDa on silver-stained SDS-PAGE gel. HFB-NJ1 also presented properties such as surface modification of glass and stable emulsification of sunflower oil. HFB-NJ1 depicted exceptional antibacterial activity against bacterial pathogens such as Bacillus subtilis and Pseudomonas aeruginosa at low MIC of 0.5 μg/mL and 0.75 μg/mL respectively. Additionally, HFB-NJ1 depicted enhanced emulsification of various vegetable and petroleum-based oils (E24 > 80%). HFB-NJ1 effectively reduced gold ions, producing nanospheres with a size of 15.33 nm – a recognized antimicrobial agent. This study underscores the multifunctional attributes of HFB-NJ1, highlighting its efficacy in removing pathogenic bacteria, emulsifying organic compounds from wastewater, and demonstrating a reduction ability for nanoparticle synthesis.

Production of structured lipids via batch and continuous acidolysis of triglycerides using the hydration–aggregation-pretreated lipase loaded onto surface-modified glass bead supports

A commercial lipase from Rhizopus japonicus was activated and utilized for triglyceride (TG) modification for producing structured lipids via acidolysis of TGs and fatty acids. To activate the lipase, lipase powder was mixed with glass beads (GBs) in 1-dodecanol and then a buffer solution were added dropwise to form hydrated lipase aggregates. After removal of liquid phase in the mixuture, the residue consisting of hydrated lipases and GBs was lyophilized and then the hydration–aggregation-pretreated lipase loaded onto GBs was recovered. The acidolytic activity of the lipase was significantly enhanced after hydration–aggregation pretreatment, whereas untreated lipase exhibited little activity. The effects of the surface hydrophobicity, diameter, and amount of lipase loading on GBs on the acidolytic activity of the lipase were investigated. The optimal GBs and lipase loadings were 0.428 mm in diameter with a hydrophobic surface and 89.2 U/g-GB, respectively. Under these conditions, the lipase exhibited an 8-fold higher catalytic activity than that of the hydration–aggregation-pretreated lipase without GBs. Furthermore, continuous modification of olive oil with palmitic acid via acidolysis using the hydration–aggregation-pretreated lipase packed in a column reactor was achieved for 116 h. The half-life of the packed-bed reactor was 149 h.

UV emitting glass: A promising strategy for biofilm inhibition on transparent surfaces

Marine biofouling causes serious environmental problems and has adverse impacts on the maritime industry. Biofouling on windows and optical equipment reduces surface transparency, limiting their application for on-site monitoring or continuous measurement. This work illustrates that UV emitting glasses (UEG) can prevent the establishment and growth of biofilm on the illuminated surfaces. Specifically, this paper describes how UEGs are enabled by innovatively modifying the surfaces of the glass with light scattering particles. Modification of glass surface with silica nanoparticles at a concentration 26.5 μg/cm2 resulted in over ten-fold increase in UV irradiance, while maintaining satisfactory visible and IR transparency metrics of over 99 %. The UEG reduced visible biological growth by 98 % and resulted in a decrease of 1.79 log in detected colony forming units when compared to the control during a 20 day submersion at Port Canaveral, Florida, United States. These findings serve as strong evidence that UV emitting glass should be explored as a promising approach for biofilm inhibition on transparent surfaces.

Exploring the advancements in surface-modified bioactive glass: enhancing antibacterial activity, promoting angiogenesis, and modulating bioactivity

Exploring the advancements in surface-modified bioactive glass: enhancing antibacterial activity, promoting angiogenesis, and modulating bioactivity

Superior antibacterial surfaces using hydrophilic, poly(MPC) and poly(mOEGMA) free chains of amphiphilic block copolymer for sustainable use

Surface modification of electrically neutral hydrophilic polymers is one of the most promising methods for preventing biofouling and biological contamination by proteins and bacteria. Surface modification of inorganic materials such as silica-based glass can render them more durable and thus help in achieving the sustainable development goals. This study reports a novel method for the simple and effective surface modification of glass surfaces with amphiphilic block copolymers possessing the silane coupling segment composed of 3-(methacryloyloxy)propyltris (trimethylsilyloxy) silane and 3-methacryloxypropyltrimethoxysilane. The ability of hydrophilic segments composed of either 2-methacryloyloxyethyl phosphorylcholine (MPC) or poly(ethylene glycol) methyl ether methacrylate (mOEGMA) to prevent bacterial adhesion was investigated. The target block copolymers were prepared by reversible addition-fragmentation chain transfer polymerization and the monomer units of the hydrophilic segments were controlled to be either 120 or 160. The polymers were modified on the substrate by dip-coating. Contact angle measurements indicated that the block copolymer with the PMPC hydrophilic segment formed a hydrophilic surface without pre-hydration, while those with the PmOEGMA hydrophilic segment-coated surface became hydrophilic upon immersion in water. The block copolymer-coated surfaces decreased S. aureus adhesion, and a significant reduction was observed with the MPC-type block copolymer. The following surface design guidelines were thus concluded: (1) the block copolymer is superior to the random copolymer and (2) increasing the hydrophilic segment length further decreases bacterial adhesion.

Surface modification of bioactive glasses for successful incorporation with poly(lactic-co-glycolic acid) (PLGA)

SBF treatment of bioactive glass improved surface roughness and bonding, aiding integration with polymers in eco-friendly composite fabrication, potentially replacing silane agents.

Surface-Modified Electrospun Glass Nanofibers from Silane Treatment and Their Use for High-Performance Epoxy-Based Nanocomposite Materials.

As a new and promising reinforcing filler, electrospun glass nanofibers (EGNFs) have attracted attention in the field of polymer composite materials. However, the reinforcing effectiveness of surface-modified EGNFs using different silane coupling agents in epoxy resin is still not quite clear. In this research, a series of silane coupling agents with increasing chain lengths in the order of methyl trimethoxysilane (MTMS), (3-aminopropyl) triethoxysilane (APTES), (3-glycidyloxypropyl) trimethoxysilane (GPTMS), and dual silane coupling agent APTES-GPTMS were employed to carry out surface treatment on the EGNFs. The pristine and silane functionalized EGNFs were then incorporated into epoxy resin as reinforcing fillers at low loading levels, i.e., 0.25 wt.%, 0.5 wt.%, and 1 wt.%, and the mechanical properties of the resultant epoxy nanocomposites, including strength, stiffness, ductility, and toughness, were evaluated. A commercial product of glass nanoparticles (GNPs) was used as a control to compare the reinforcing effectiveness of the EGNFs and the GNPs. This study revealed that the EGNFs could provide significant reinforcing and toughening effects at ultra-low loading (0.25 wt.%) in epoxy nanocomposite materials. Furthermore, surface modification of the EGNFs with silane coupling agents with long chain lengths, e.g., by using dual silane coupling agents, APTES-GPTMS, could enhance the interfacial bonding between the EGNFs and the epoxy matrix and further increase the mechanical performance of the EGNF-reinforced epoxy nanocomposite materials. Through this research, we realized epoxy nanocomposite materials with much-improved mechanical properties, i.e., 37%, 24%, 18%, 57% improvement in strength, stiffness, ductility, and toughness, respectively, with respect to those of the cured neat epoxy material with an ultra-low loading (0.25 wt.%) of APTES-GPTMS-EGNFs. Our research paves the road for developing lighter and stronger epoxy nanocomposite materials with EGNFs.

Study on surface modification and optical properties of Nd-doped phosphate glass

Using laser neodymium glass (N31) as the substrate, through ion exchange and hydrogen reduction process, a high-efficiency light absorption layer was formed from the substrate around the glass. It has been discovered that increasing the ion exchange temperature and time enhanced the exchange depth of laser glass, but excessive temperature and prolonged time will lead to corrosion of laser glass. The experiment shows that the best exchange temperature is 460°C and the best exchange time is 720min. When the hydrogen pressure was 0.8MP, the reduction temperature was 480°C and the reduction time was 12000 min, the absorption rate of the sample at 1053nm was 95.8%.

Stable superhydrophobic coating on Zr-based bulk metallic glass exhibiting excellent antibacterial property and cytocompatibility

A central challenge in the study of clinical medicine is to reduce the infection rate of implants without affecting cell adhesion and reproduction. For the first time, we prepared a robust and stable superhydrophobic Zn/pDop/SA coating on Zr56Al16Co28 bulk metallic glass by electrodeposition that exhibits a maximum water contact angle of 158° and a sliding angle less than 1°. The growth of the coating micro-nano structure was controlled by changing the electrodeposition process parameters. The coating showed excellent antimicrobial adhesion properties in the environment to avoid bacteria adhesion and can transform from superhydrophobic to hydrophilic in body fluids to promote cell adhesion. The biodegradation of the Zn crystal structure was responsible for the hydrophobic transformation of the coating and the rough surface after biodegradation provided a point of adhesion for the cells. By designing a uniform crater structure on the substrate as an “armour” and co-depositing dopamine into the coating, the coating’s wear resistance was greatly improved. The superhydrophobic coating can maintain stable superhydrophobicity in high temperature environment, air and UV irradiation. This study opens new horizons for the surface modification of bulk metallic glass and promotes its application in the medical field.

Surface modification of silicate, borosilicate and phosphate bioactive glasses to improve/control protein adsorption: PART I

Bioactive glasses (BGs) are promising for bone tissue regeneration. BG composition can be tailored, according to the application of interest, and/or functionalized with organic molecules/biomolecules to improve their performances. However, despite the wide knowledge concerning BGs, their interaction with proteins, fundamental for controlling the fate of the implant, has not been deeply investigated yet. Controlling or predicting protein adsorption requires a full understanding of the materials surface physico-chemical properties. In this work, four different BGs (S53P4, B25, SCNB, PhGlass) were surface-modified by four different treatments: 72 h-soaking in TRIS, 72 h soaking in simulated body fluid, APTES grafting and quaternized APTES grafting. The surfaces were then characterized both untreated and after each treatment by contact angle, zeta potential analysis, X-ray photoelectron spectroscopy, Fourier Transform InfraRed–Attenuated Total Reflectance spectroscopy and Scanning Electron Microscopy and Energy Dispersive Spectroscopy. Inductively Coupled Plasma – Optical Emission Spectrometry was then performed to investigate the ion leaching. The aim of this study (Part I) is the physico-chemical characterization of BGs as a function of the implemented treatments, aiming to better understand how the superficial properties are successively affecting protein adsorption. Protein adsorption on untreated and treated BGs will be discussed in a following manuscript (Part II).

Antifouling superhydrophilic porous glass membrane based on sulfobetaine prepared by thiol−ene click chemistry for high-efficiency oil/water separation

Compared to superhydrophobic/superoleophilic membranes for high-efficiency oil/water separation, superhydrophilic membranes displaying underwater superoleophobic properties show improved antifouling performance. Nevertheless, superhydrophilic/underwater superoleophobic surfaces reported so far, in general, are susceptible to oil contamination. In addition, the tricky fabrication methods towards the superhydrophilic membranes also severely limit practical applications of such materials. Herein, we prepared novel superhydrophilic/underwater superoleophobic porous glass membranes with excellent oil fouling resistance via one-step in situ growth of silicone nanofilament network layers on the surface of sand particle-based sintered glass filters using vinyltrichlorosilane (VTCS) as a precursor, followed by grafting of a thiol-functionalized of sulfobetaine by thiol-ene click chemistry. The sulfobetaine-modified porous glass membranes showed excellent underwater superoleophobicity even for viscous crude oil. Besides, such surface-modified glass membranes exhibited high efficiency for the separation of various oil-water mixtures (>99.992%) and oil-in-water emulsions (>99.968%), even for those involved with viscous crude oil (99.982%). Owing to its superior antifouling properties, the sulfobetaine-modified glass membranes display excellent reusability for the separation of oil-water mixtures and oil-in-water emulsions. The outstanding advantages with characteristics of easy-to-fabricate, low-cost, excellent antifouling properties, and high separation performance enable the sulfobetaine-modified porous glass membranes with great potential for oily sewage treatment.

Surface modification of silicate, borosilicate, and phosphate bioactive glasses to improve/control protein adsorption: PART II

Bioactive glasses (BGs) are characterized by high biocompatibility and bioactivity and are particularly promising for bone tissue regeneration. Once implanted, the BGs interact with the environment and adsorb chemical moieties and biomolecules. Proteins in body fluids are critical for the success of implants, because the adsorption of specific proteins can either promote or inhibit the adhesion of surrounding tissue or other factors such as bacteria. Controlling protein adsorption by tailoring the surface properties of implanted biomaterials is fundamental. This can determine the fate of the implant. In the current study, four BG compositions (two silicates, one borosilicate, and one phosphate glass) and three model proteins (fibronectin, chimeric avidin, and streptavidin) were considered. Each BG was surface pretreated, and the adsorption of fluorescently labeled fibronectin, chimeric avidin, or streptavidin was monitored. Untreated surfaces were used as controls. The amount and spatial distribution of each protein were estimated by confocal microscopy in fluorescence modality, followed by protein clustering analysis. Although streptavidin was not adsorbed efficiently on any of the considered substrates, BGs were successfully coated with fibronectin and chimeric avidin. Both proteins showed different affinities and surface distributions as functions of the implemented pretreatment on each substrate.

Fatigue-Induced Surface Modification of Zr-Based Metallic Glass under Environmental Conditions.

Metallic glass (MG), an intrinsic heterogeneous structure at the atomic scale, is one of the promising engineering materials with intriguing physical properties. MG often suffers from the fatigue issue caused by the repetitive mechanical loading, but it is still elusive how the local heterogeneity evolves and affects the macroscale fatigue and deformation against bulky external stress. In this study, we investigate the fatigue effect in Zr-Cu-Al ribbon using a bending fatigue method. We used scanning probe microscopy (SPM) in parallel with X-ray diffraction and X-ray photoelectron spectroscopy to figure out the loading effect on the local heterogeneities. The spatially resolved SPM images show that there is a local fluctuation of mechanical and electrical properties on the fatigued side along with morphological deformation compared to the unloaded side. Approaching the broken edge where the fatigue failure occurs, the decaying tendency is not only more dominant but also accelerated by surface oxidation of the fatigued regions. Our study provides a useful guideline on how to monitor structural changes of MGs under fatigue conditions in service and will open a door toward commercialization of high-performance structural engineering materials.

Antibacterial effect of surface-modified Zr50Cu50 metallic glass

Zr-based metallic glasses generally have an amorphous zirconium oxide film that strongly inhibits further oxidation. However, surface defects may deteriorate the glass stability of the amorphous oxide film, leading to the formation of a thick natural oxide layer. In this study, we demonstrated that the change in the oxidation behavior of a melt-spun Zr50Cu50 metallic glass foil caused by the surface casting defects on its wheel side can lead to a dramatic improvement in antibacterial properties. The superior antibacterial properties of the wheel side was attributed to the metallic Cu islands exposed on the surface.

Laser based surface treatment of bioactive glass: Dependence on pulsed laser ablation

Experimental results and theoretical simulation of material ablation on nanosecond Nd:YAG laser irradiation of bioactive glass targets, is presented. The process of pulsed laser ablation critically affects both, laser based surface modification and pulsed laser deposition (PLD) of bioactive glass (BG). A thermal model based theoretical simulation has been carried out describing heat-transport, melting and vaporization of a laser irradiated BG target under near-threshold ablation conditions. Calculated mass ablation rate per laser pulse has been compared with our experimental observations over the average laser fluence of 0.5J/cm2 to 6J/cm2. With increasing laser fluence, possibility of material ablation approaching phase explosion has been discussed by comparing the calculated maximum temperature reached by the laser irradiated target and the estimated thermodynamic critical temperature for BG. Our investigations indicate that with average laser fluence restricted to ∼5 J/cm2 material ablation occurs largely via normal vaporization ensuring deposition of an uniform, homogeneous BG coating through PLD. Target surface temperatures estimated from our calculations also suggest that laser based surface modification of BG can be reproducibly carried out without causing target crystallization and surface damage through crater formation for irradiating laser fluence in the region of ∼ 5J/cm2.

Controlling Lengthscales in Water-Solvent Induced Self-Organized Dewetting of Thin Polystyrene Films by Modulating the Surface Properties of the Substrate

We report here a facile method of modulating the lengthscales of self-organized dewetting of polystyrene thin films by varying the extent of silane grafting on the substrate. The self-assembled monolayers (SAM) of octadecyltrichlorosilane (OTS) were grafted on glass substrates by exposing them to different doses of OTS vapors in a controlled, low pressure environment. Measurement of water contact angles on the modified glass surfaces showed that the contact angles could be continuously increased from 40° to 70° by increasing the time of exposure to the OTS vapors from a few minutes to several hours. Polystyrene (PS) thin films were spin coated on the modified glass substrates and water-solvent mixture induced dewetting of the PS thin films was carried out, where the dewetting kinetics depended on the spreadability of water on the surface. We observed a reduction in the length scales of the dewetting, i.e. the wavelength of instability (λ) and droplet size (d), by increasing the extent of OTS exposure. The λ for a 50 nm thick PS film decreased from 12 to 4 µm while the droplet diameter (d) also decreased, from 2.5 to 1.6 µm.

Glass Surface Modification Was Induced by the Combination of Coating Technology and Femtosecond Laser Assisted Chemical Etching

Due to its high hardness and high transmittance, ultra-white glass has a strong application prospect in the fields of optoelectronics industry and experimental instruments. However, because of its brittleness, it was still a difficult problem in the machining industry. Surface modification provides a basic research idea for ultra-white glass microstructure processing. An effective method to obtain surface modified area on ultra-white glass was presented. The modified zone on the surface of ultra-white glass was induced by the technique of coating and femtosecond laser-assisted chemical etching. The method combines vacuum coating with femtosecond laser irradiation. Next, the modified glass was processed with highly selective potassium hydroxide solution. In order to control the surface size more efficiently, the optimization experiment of laser parameters and chemical parameters on the machining process was carried out. The experimental results show that the method made the surface modification of ultra-white glass more easily and provides basic research for fabricating microchannels on the material.

Surface modification of glass fiber membrane via insertion of a bis(diarylcarbene) assisted with polymerization and cross-linking reactions

Glass Fiber (GF) membrane was modified using bis(diaryldiazomethane) derivatives with various terminal functionalities and characterized via multiple techniques including SEM, XPS, ATR-IR, proving successful modification and offering an alternative route to surface-modified glass materials. Significant changes in surface wetting were observed by successive functionalization of the GF surface. Surface modification was proposed to proceed through two independent mechanisms, the first being insertion via carbene into surface X-H (Si-O-H) bonds, while the second is polymerization by propagation of the carbene with active surface terminal amine functions; this is the first time that carbene-mediated polymerization at a modified surface has been identified. This latter process proceeds without catalysis by transition metals, and leads to encapsulation of the glass fibres. This approach is complementary to traditional silane coupling reagents, producing bis(diarylcarbene) (in short, biscarbene)-modified GF membrane in which surface physical and chemical properties have been modified independently of the bulk.

A cuvette-compatible Zn2+ sensing tool for conventional spectrofluorometers prepared by copolymerization of macrocyclic fluoroionophores on quartz glass surface

We report here the development of a surface-modified quartz glass sheet, which affords an opportunity for converting conventional spectrofluorometers to ion-selective optochemical sensors by placing it diagonally into a photometric cuvette. Moreover, we describe a generalizable technique, which allows the usage of any polymerizable ionophores for developing multiple-use fluorescent chemosensors of various selectivity. A fluorescent bis(acridino)-crown ether containing allyl groups was photocatalytically copolymerized with a methacrylate-acrylamide-based monomer mixture to obtain an ion-selective sensor membrane layer on the surface of the cuvette-compatible glass sheet. This glass membrane-based direct optode enabled the analysis of Zn2+ above a lower limit of detection of 2.2 × 10–7 mol·l−1 with an excellent reusability. Limiting factors, like pH and competing ionic or organic agents were thoroughly investigated. Moreover, spiked river-water samples were measured to demonstrate applicability. The proposed sensor placed in any conventional spectrofluorometer provides an innovative method for perturbation-free analysis of Zn2+ for all the chemists in need of a fast, easy-to-use, portable and regenerable analyzer without the requirement of an analyte-specific instrumentation.

Infrared Nanosecond Laser Texturing of Cu-Doped Bioresorbable Calcium Phosphate Glasses

The surface modification of bioactive glasses significantly impacts their performance for in-vivo biomedical applications. An affordable nanosecond pulsed laser surface-modification technique would provide great flexibility in applications such as cell scaffolding and fouling/anti-fouling engineered surfaces. This study reports on an infrared nanosecond laser modification technique we developed and applied to a Cu-doped bioresorbable calcium phosphate glass. With this technique, clean micro-protrusion features could be produced. By tuning the laser parameters such as the laser scan speed and average power, the width and height of the formed protrusions could be controlled. Finally, optimal laser parameters were defined to obtain complex surface textures without significant damage or thermal-stress-induced cracks. These results could provide effective aid for the affordable, fast, and selective surface texturing of metal-doped bioglasses, opening new possibilities in their application in the biological field.