Modification Of Glass Research Articles

Dependency of the type of oxygen bonds on the roughness of classically manufactured fused silica surfaces

Glass polishing is a complex process where the formation of the final surface results from several quite different mechanisms – pure mechanical abrasion, wear-induced fretting, flow-induced surface smoothing, and glass modification and removal via chemical reactions. The aim of the study is thus to analyse the chemical composition and surface roughness throughout the entire classical optics manufacturing process of fused silica, which includes the production steps of cutting, grinding or lapping, and polishing, using X-ray photoelectron spectroscopy and atomic force microscopy. It is shown that the analytical results are in good accordance with the polishing theory initially suggested by Beilby, Bowden and Hughes in the 1920s and 1930s. The decomposition of the oxygen peak from the detail XPS spectra allowed a subdivision of Si–O bonds into silicon dioxide and silanol such as Si–OH or Si(OH)4, which enabled a direct correlation between the SiO2 and silanol concentration and the surface roughness occurring for the particular manufacturing steps.

From Localized Laser Energy Absorption to Absorption Delocalization at Volumetric Glass Modification with Gaussian and Doughnut-Shaped Pulses

Volumetric modification of transparent materials by femtosecond laser pulses is successfully used in a wide range of practical applications. The level of modification is determined by the locally absorbed energy density, which depends on numerous factors. In this work, it is shown experimentally and theoretically that, in a certain range of laser pulse energies, the peak of absorption of laser radiation for doughnut-shaped (DS) pulses is several times higher than for Gaussian ones. This fact makes the DS pulses very attractive for material modification and direct laser writing applications. Details of the interactions of laser pulses of Gaussian and doughnut shapes with fused silica obtained by numerical simulations are presented for different pulse energies and compared with the experimentally obtained data. The effect of absorbed energy delocalization with increasing laser pulse energy is demonstrated for both beam shapes, while at relatively low pulse energies, the DS beam geometry provides stronger local absorption compared to the Gaussian geometry. The implications of a DS pulse action for post-irradiation material evolution are discussed based on thermoelastoplastic modeling.

Nanosecond laser-induced filamentous modification in silicate glasses

Laser-induced filamentous modification (LIFM) has been extensively studied in transparent materials and is widely used for cutting and drilling with a high aspect ratio. However, the discussion focuses on the domain of ultra-short pulses recently, such as picosecond and femtosecond pulses. In this work, a LIFM by a short pulse in silicate glasses is demonstrated, and the physical mechanism is investigated. In the soda-lime glass, a filamentous modification with a length of >650 μm was introduced by a nanosecond pulse with an energy of 0.86 mJ. The average length of LIFM is positively correlated with the pulse energy but is not affected by the focus depth significantly. Furthermore, LIFM is also observed in borosilicate glass and K9 glass, but not in fused silica glass. Theoretical analysis shows that the contribution of the self-focusing and optical error to LIMB could be ignored in soda-lime glass. An improved Laser-induced moving breakdown (LIMB) model is proposed to describe LIFM by a nanosecond pulse, and the thermal explosion (TE) model is used to explain the micro-structures. High-density defects dominate the LIMB of nanosecond pulses in silicate glasses, which provide seed electrons for laser-induced ionization and induce a thermal explosion through enhanced absorption. The estimation result of the TE model shows that the final temperature of thermal plasma exceeds 1 × 105 K, resulting in micro-explosion and forming micro-voids and micro-crack clusters. Based on the principle of LIFM, stealth cutting was implemented by a high-frequency nanosecond laser in soda-lime glass with a thickness of 2 mm, and the cutting speed reaches 3000 mm/s.

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%.

Modification of Liquid Glasses Is a Key Factor in the Technology of Obtaining Hybrid Compositions and Coatings with Anticorrosive Properties

The aim of the work was to investigate the prospects of imparting valuable physical and chemical properties, such as corrosion resistance, impact and bending strength, adhesion and storage stability, to hybrid systems of potassium and sodium silicates by modification with organic compounds. Here, we present the results of worldwide activities of scientific teams studying the manufacturing technology of modified liquid glass anticorrosive coatings used in chemical, petrochemical industry and modern construction. The authors theoretically and economically justified and put into practice novel organic and inorganic compositions with increased viability. The durable and waterproof coatings with good adhesion to various substrates (non-ferrous metals, steel, plastered surface and wood) were obtained. The authors demonstrate the possibility of recycling of zinc-containing rongalite production wastes and sludge pastes of electrochemical productions containing alkali and alkaline-earth metal cations by including them into the composition instead of pigmenting solid-phase components. We propose a technological route for obtaining anticorrosion coatings to protect aluminum and its alloys operated in a zone of elevated (up to 673 K) temperatures.

Rapid quench piston cylinder apparatus: An improved design for the recovery of volatile-rich geological glasses from experiments at 0.5-2.5 GPa.

The accurate and precise determination of the compositions of silicate glasses formed from melts containing volatile components H2O and CO2 recovered from high-pressure, high-temperature experiments is essential to our understanding of geodynamic processes taking place within the planet. Silicate melts are often difficult to analyze chemically because the formation of quench crystals and overgrowths on silicate phases is rapid and widespread upon quenching of experiments, preventing the formation of glasses in low-SiO2 and volatile-rich compositions. Here, we present experiments conducted in a novel rapid quench piston cylinder apparatus on a series of partially molten low-silica alkaline rock compositions (lamproite, basanite, and calk-alkaline basalt) with a range of water contents between 3.5 and 10 wt%. Quench modification of the volatile-bearing silicate glasses is significantly reduced compared to those produced in older piston cylinder apparatuses. The recovered glasses are almost completely free of quench modification and facilitate the determination of precise chemical compositions. We illustrate significantly improved quench textures and provide an analytical protocol that recovers accurate chemical compositions from both poorly quenched and well-quenched silicate glasses.

Effect of Pulse Repetition Rate on Ultrafast Laser-Induced Modification of Sodium Germanate Glass

We report an unexpected pulse repetition rate effect on ultrafast-laser modification of sodium germanate glass with the composition 22Na2O 78GeO2. While at a lower pulse repetition rate (~≤250 kHz), the inscription of nanogratings possessing form birefringence is observed under series of 105-106 pulses, a higher pulse repetition rate launches peripheral microcrystallization with precipitation of the Na2Ge4O9 phase around the laser-exposed area due to the thermal effect of femtosecond pulses via cumulative heating. Depending on the pulse energy, the repetition rate ranges corresponding to nanograting formation and microcrystallization can overlap or be separated from each other. Regardless of crystallization, the unusual growth of optical retardance in the nanogratings with the pulse repetition rate starting from a certain threshold has been revealed instead of a gradual decrease in retardance with the pulse repetition rate earlier reported for some other glasses. The repetition rate threshold of the retardance growth is shown to be inversely related to the pulse energy and to vary from ~70 to 200 kHz in the studied energy range. This effect can be presumably assigned to the chemical composition shift due to the thermal diffusion of sodium cations occurring at higher pulse repetition rates when the thermal effect of the ultrashort laser pulses becomes noticeable.

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.

A facile finger-paint physical modification for bilateral electrode/electrolyte interface towards a stable aqueous Zn battery

Since the electrode/electrolyte interface (EEI) is the main redox center of electrochemical processes, proper manipulation of the EEI microenvironment is crucial to stabilize interfacial behaviors. Here, a finger–paint method is proposed to enable quick physical modification of glass–fiber separator without complicated chemical technology to modulate EEI of bilateral electrodes for aqueous zinc–ion batteries (ZIBs). An elaborate biochar derived from Aspergillus Niger is exploited as the modification agent of EEI, in which the multi–functional groups assist to accelerate Zn2+ desolvation and create a hydrophobic environment to homogenize the deposition behavior of Zn anode. Importantly, the finger–paint interface on separator can effectively protect cathodes from abnormal capacity fluctuation and/or rapid attenuation induced by H2O molecular on the interface, which is demonstrated in modified MnO2, V2O5, and KMnHCF–based cells. The as–proposed finger–paint method opens a new idea of bilateral interface engineering to facilitate the access to the practical application of the stable zinc electrochemistry.

In-situ study of phase changes in glass by impedance spectroscopy and scaling

Transformation in “evolving glass” in ion-conducting silicate glasses, glass ceramics or ceramics containing an intergranular glass is studied by in-situ impedance spectroscopy and scaling laws. Approaches are developed to scale frequency-dependent electrical conductivity and dielectric properties of multiphase ion-conducting materials to derive temperature-independent information on bulk phases and interfaces in presence. A material's scaled electric conductivity provides a unique response over a range of temperature, if the material remains unaltered, but changes, once modifications in the material occur. Therefore, impedance spectroscopy in combination with scaling can be used for tracking modifications in structure, organization, chemistry and microstructure in “evolving (ion-conducting) glass”.In a first part of this work, our approach is validated through application to stable silicate glasses and glass ceramics. Then “evolving glass” is studied in bulk glasses and ceramics with intergranular glass. Examples include ceramming of glass under formation of a glass ceramic, glass-glass phase separation, modification of intergranular glass in ceramics as result of chemical reactions or melt corrosion.Our approach allows to determine onset of phase separation, nucleation or reaction with high precision. It further reveals that nucleation in our exemplary lithium aluminum silicate glass starts with formation of interfaces (phase separation) prior to forming a well-organized crystal lattice. During phase separation in glass, early capacitive contributions in the impedance spectra indicate that the formation of glass-glass interface precedes the compositional changes in the bulk glass.Impedance of refractories is monitored during thermal treatments or corrosion in glass melt at temperatures up to 1600 °C, and glass characteristics of refractories with glass content as low as 3% are extracted. Conductivity and/or level and/or interconnectivity of the refractory's glass are shown to change during thermal treatments due to reactions between glass and crystalline refractory phases, due to phase transformation or, in case of melt corrosion, due to melt infiltration and ion exchange with the melt.In-situ tracking of impedance and application of scaling laws is shown to be able to reveal changes in bulk glass and intergranular glass.

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).

WAYS FOR IMPROVEMENT THE OSTEOPLASTIC MATERIALS FOR DENTISTRY. Review

Relevance. Bone-graft materials are widely used in health care and dentistry in particular. The use of osteoplasty techniques in the oral cavity has an increased risk of contamination of the operating field with opportunistic and pathogenic microflora. A number of improvements in such materials have the potential to be used in the treatment of dental diseases.
 Objective: to analyze current publications devoted to the improvement of bone gratf materials that are used in health care and can be used in dentistry.
 Methods. An analysis of data obtained during an information search in the online databases "PubMed", "SciELO", "Medcape" and "Science of Ukraine: access to knowledge" was carried out using the keywords "osteoplasty", "bone substitute materials", " bone defects".
 Results: Despite the predominance in clinical practice of the use of osteoplastic materials of animal origin, the development and improvement of artificial materials looks promising. Such directions can be the improvement of composite materials based on hydrophilic gels which are able to be resorbed in the human body. Modification of ceramic materials and biological glass, improvement of their osteoconductive properties. Inclusion of antibiotics and antiseptics to osteoplastic materials. Inclusion of natural and recombinant biological growth factors in the composition of bone substitute materials. Transformation of osteoplastic material into a system of controlled long-term emission of antibiotics, antiseptics and biological growth factors.
 Conclusions: Modern osteoplastic materials used in dentistry are mainly high-tech medical products that continue to be improved. The creation of artificial and composite materials with additional antiseptic, antibacterial, osteoinductive and biological properties opens the way to improving the methods of dental treatment and osteoplasty for the needs of dentistry.

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.

Large field‐of‐view holographic imager with ultra‐high phase sensitivity using multi‐angle illumination

Quantitative phase imaging and holography allow highly sensitive detection of phase changes, for example of surface non-uniformities or refractive index (RI) structures in the volume of a sample. For many applications, wide field-of-view (FoV) and high phase sensitivity are required. Lens-free interferometric microscopy can operate over a wide FoV and volume, but with the drawbacks of low axial resolution and poor optical sectioning, which comes with increased noise from out-of-focus planes. In this work, we propose and demonstrate a novel implementation of lens-free phase imaging with phase-shifting interferometry and multi-angle illumination that enhances axial resolution and image quality, enabling ultra-high phase sensitivity with optical path difference (OPD) background root-mean-square (RMS) noise of 0.2 nm, while operating over a wide FoV (>10 mm²). As a prototypical application, we demonstrate imaging of 10 nm thin transparent glass structures, and of 3D laser-written structures of RI modifications in glass over a large volume (>10 mm³), where the location of features along the z-axis can be determined with 3x higher accuracy compared to an on-axis illumination. The technology is particularly suitable for large-scale analysis and characterization of structures on the surface or embedded in transparent materials.

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.

Precisely Tuning the Pore-Wall Surface Composition of Bioceramic Scaffolds Facilitates Angiogenesis and Orbital Bone Defect Repair.

Orbital bone damage (OBD) may result in severe post-traumatic enophthalmos, craniomaxillofacial deformities, vision loss, and intracranial infections. However, it is still a challenge to fabricate advanced biomaterials that can match the individual anatomical structure and enhance OBD repair in situ. Herein, we aimed to develop a selective surface modification strategy on bioceramic scaffolds and evaluated the effects of inorganic or organic functional coating on angiogenesis and osteogenesis, ectopically and orthotopically in OBD models. It was shown that the low thermal bioactive glass (BG) modification or layer-by-layer assembly of a biomimetic hydrogel (Biogel) could readily integrate into the pore wall of the bioceramic scaffolds. The BG and Biogel modification showed appreciable enhancement in the initial compressive strength (∼30-75%) or structural stability in vivo, respectively. BG modification could enhance by nearly 2-fold the vessel ingrowth, and the osteogenic capacity was also accelerated, accompanied with a mild scaffold biodegradation after 3 months. Meanwhile, the Biogel-modified scaffolds showed enhanced osteogenic differentiation and mineralization through calcium and phosphorus retention. The potential mechanism of the enhanced bone repair was elucidated via vascular and osteogenic cell responses in vitro, and the cell tests indicated that the Biogel and BG functional layers were both beneficial for in vitro osteoblastic differentiation and mineralization on bioceramics. Totally, these findings demonstrated that the bioactive ions or biomolecules could significantly improve the angiogenic and osteogenic capabilities of conventional bioceramics, and the integration of inorganic or organic functional coating in the pore wall is a highly flexible material toolbox that can be tailored directly to improve orbital bone defect repair.

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.

Induced linear and nonlinear optical modifications of nickel cadmium borosilicate glass by sunlight irradiation

Herein, we investigate the impacts of sunlight on different optical parameters of borosilicate glasses containing nickel, barium, and cadmium oxides. We studied the influence of sunlight on the optical band gap (Eg), Urbach energy (EU), refractive index (n), and nonlinear refractive index (n2) at different times of irradiations; t = 0, 40, 60, and 120 min. The absorbance of all glass samples showed a decreasing behavior, particularly in the ultraviolet (UV) range. The reduction in the UV absorption band at around 307 nm is ascribed to the photo-reduction of Fe3+ to Fe2+, producing a decrease in the amount of Fe3+ in the glass samples. The percents of changes for the studied optical parameters such as Eg, EU, n, and n2 are insignificant (<10%), confirming the glasses' stability under the effect of solar irradiation. The good stability of the investigated glasses makes them good candidates for optical applications, especially those exposed repeatedly to sunlight, such as smart windows and solar cell panels.

Thermal and structural modification in transparent and magnetic gallogermanate glasses induced by Gd2O3

A series of new transparent and magnetic barium gallogermanate glasses in the system ( x ) Gd 2 O 3 – (100- x ) [20BaO−15Ga 2 O 3 −65GeO 2 ] with x = 0, 8, 14, 18, 22 and 25 mol% were synthesized. Their thermal, structural and magnetic properties were characterized. Based on the differential scanning calorimetry results, one determined the composition domain exhibiting the highest thermal stability toward crystallization and provided a detailed experimental fabrication method for the production of optical fibers. The local glass structure investigated using combined Raman and Infrared vibrational spectroscopies shows a progressive depolymerization of the 3D glass germanate network accompanied with an increase of non-bridging oxygens when increasing the Gd 2 O 3 content. The incorporation of gadolinium ions tends to extend the IR transmission window. Thanks to the magnetic susceptibility measurements, the paramagnetic behavior was evidenced, and increases with the Gd 3+ content. The combination of the optical, thermal and magnetic properties of Gd 2 O 3 gallogermanate glasses as well as their ability to be shaped into optical fibers make them promising materials for their integration in MIR functional optical components. • Novel transparent and magnetic glasses in the system Gd 2 O 3 – BaO − Ga 2 O 3 − GeO 2 were synthesized by melt-quenching method. • Investigation of thermal, structural and magnetic properties. • Fabrication of paramagnetic fibers was demonstrated using preform-to-fiber approach. • The paramagnetic behavior was evidenced using the magnetic susceptibility measurements.

Effect of Dolomite Addition on the Structure and Properties of Multicomponent Amphibolite Glasses.

The structure and properties of the glass can be modified by introducing appropriate additives. Dolomite is one of the primary raw materials modifying the properties of glass, in which the essential component is calcium-magnesium double carbonate CaCO3∙MgCO3. The paper presents the research results on glasses obtained by smelting pure amphibolite and amphibolite modified with 10 and 20% dolomite additives. The raw material used was mined in the Poland region of Lower Silesia. The glass melting process was carried out in an electric furnace at 1450 °C for 2 h. The structure and properties of the glasses and crystallization products were determined by Differential Scanning Calorimetry (DSC), X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy—Energy Dispersive Spectroscopy (SEM-EDS). Viscosity and Vickers microhardness were also measured. It was found that the modification of amphibolite glass by adding dolomite affects the glasses’ properties and structure. The research results determined the effect of dolomite addition on the properties of alumino-silicate glasses in terms of the mineral fibre products used in the construction industry.