Glass Addition Research Articles

Two-step sintering technique of LATP ceramic electrolyte with enhanced key parameters

A new preparation technique of Li1.3Al0.3Ti1.7(PO4)3 (LATP) ceramics is focused on optimisation of weight fractions of LATP glass additives into green ceramic powder followed by enhanced two-step sintering to improve key parameters of relative density and ionic conductivity of LATP solid-state electrolyte (SSE) pellets. The LATP SSE has been obtained with the relative density and ionic conductivity of (96.3±0.2)% and (8.0±0.2)×10−4 S/cm, respectively, after pre-annealing at 570°C for 6 h and sintering at 900°C for 6 h of mixed glass and ceramic powders with an optimal weight ratio of 5%/95%. Notably, the Li||LATP||Li symmetric cell using such LATP SSE could maintain voltage stability for 300 h, and the Li||LATP||NCM111 full cell exhibits good cycling performance over 100 cycles with capacity above 100 mAh/g (capacity retention of 79.1%). The proposed simple technique seems to be effective to improve the relative density and ionic conductivity thus acclerating the development of all-solid-state lithium metal battery.

Analysis of the Mechanical Properties of Concrete Blocks Reinforced With Glass Particles and Recycled Paper: A Sustainable Approach

The materials to produce concrete blocks (sand, gravel, and cement) are limited resources that are becoming scarce over time due to their increasing demand in construction. On the other hand, the waste of glass and paper is progressively increasing without being fully utilized through recycling. Therefore, the objective of this scientific research is to evaluate the influence on the mechanical properties of masonry concrete blocks made with recycled glass and paper particles. Likewise, the sample was non-probabilistically selected for convenience, consisting of 192 concrete blocks manufactured with additions of 3% (2% glass particles and 1% recycled paper), 6% (4% glass particles and 2% recycled paper), and 9% (6% glass particles and 3% recycled paper), as well as concrete blocks manufactured without additions. According to the results obtained, at 3%, 6%, and 9% addition of glass and paper particles, the absorption decreased by 4.94%, 3.398%, and 3.52% respectively. However, the warping increased between 1.7mm and 1.8mm, while the compressive strength (f'c) increased to 75kg/cm2, 82kg/cm2, and 77kg/cm2, respectively. Similarly, the axial compressive strength (f'm) increased to 91.22kg/cm2, 94.45kg/cm2, and 92.80kg/cm2, and the diagonal compressive strength (V'm) increased by 8.90kg/cm2, 9.70kg/cm2, and 9.70kg/cm2. Nevertheless, the manufacturing cost of masonry units showed a progressive reduction with the amount of glass + paper addition, amounting to 0.57 USD, 0.55 USD, and 0.53 USD. It was also determined that the optimal addition of these materials in the concrete mix in terms of cost and strength is 9% (glass + paper), resulting in compressive strengths of 77kg/cm2, 92.8kg/cm2, and 9.70kg/cm2, with a cost of 0.53 USD per unit. In conclusion, it can be affirmed that adding glass and recycled paper particles in the production of concrete blocks for use in load-bearing masonry walls positively influences the physical and mechanical properties of the blocks. Additionally, it allows for a reduction in manufacturing costs, leading to significant savings for builders.

Samarium-modified PLZST-based antiferroelectric energy storage ceramics for low-temperature sintering in reducing atmosphere

The energy storage properties of pure PLZST-based antiferroelectric ceramics are excellent; however, the high sintering temperature renders them unsuitable for co-firing with copper inner electrodes as MLCC dielectric materials. The proven BASK glass additive was employed in this study to lower the sintering temperature of PLSZT ceramics, while simultaneously doping Sm3+ ions to enhance their sintering performance under reducing atmospheres. The precise evaluation process confirmed that the addition of glass effectively reduced the sintering temperature to 1040 °C. Furthermore, the defect association of Sm3+ doping hindered the formation of oxygen vacancies, facilitated ceramic grain growth, and significantly enhanced insulation resistivity. Consequently, an ultrahigh recoverable energy density (Wrec) of 5.19 J/cm3 with a high energy storage efficiency (η) of 94.5% are achieved at an electric field of 430 kV/cm. Moreover, the AFE ceramics possess excellent discharge energy storage properties with a high discharge energy density (Wd) of 4.26 J/cm3 and a large power density (Pd) of 139 MW/cm3.

Bioprinting with adipose stem cells and hydrogel modified with bioactive glass

Bioprinting research is focused on utilizing growth factors and multiple cell types to create clinically relevant three-dimensional (3D) tissue models using hydrogels. Rheological and biological challenges are two main factors that limit the creation of extrudable bioactive hydrogels. In this study, we investigate incorporation of fast dissolving and bioactive borate glass in different weight to volume percentages (0.075 to 0.6%) to alginate-gelatin (1:1) hydrogel to improve rheological properties and enable bioprinting with bioactive glass. The addition of glass improved the stiffness of the hydrogel. Human adipose-derived mesenchymal stem cells (ASCs) were uniformly mixed in this bioink at 1 × 106 cells/mL concentration, and spheroid specimens were cultured in both static and dynamic culture conditions. Grid-shaped scaffolds measuring ~18 × 18 × 1 mm3 were fabricated with the viable glass concentrations, and ASC viability was evaluated using Live/Dead assay. Despite immediate toxicity, an increased viability after 7 days with 0.15 w/v % or less borate glass content demonstrated the potential in utilizing highly resorbable calcium-releasing biomaterials such as bioactive glasses to modify hydrogels suitable for bioprinting cellularized 3D structures.

Improving the Energy Storage Performance of Barium Titanate-Based Ceramics through the Addition of ZnO-Bi2O3-SiO2 Glass

Lead-free ceramics with excellent energy storage performance are important for high-power energy storage devices. In this study, 0.9BaTiO3-0.1Bi(Mg2/3Nb1/3)O3 (BT-BMN) ceramics with x wt% ZnO-Bi2O3-SiO2 (ZBS) (x = 2, 4, 6, 8, 10) glass additives were fabricated using the solid-state reaction method. X-ray diffraction (XRD) analysis revealed that the ZBS glass-added ceramics exhibited a perovskite structure, with the maximum relative density achieved at x = 6. The average grain size reduced obviously as the glass additive wt% increased. Also, the dielectric constant decreased and the breakdown strength increased with increases in the glass additives. The optimal energy storage density of 1.39 J/cm3 with an energy storage efficiency of 78.3% was obtained at x = 6 due to high maximum polarization and enhanced breakdown strength. The results demonstrate that this material is a potential candidate for high-pulse-power energy storage devices.

Influence of bioactive glass addition on the machinability, mechanical and biological response of Mg-PSZ-based biocomposites

The incorporation of bioactive glass (BG) into zirconia-based composite materials shows a feasible option to enhance the biological properties, reduce the sintering temperature, and resist the transformation of the tetragonal phase of zirconia. In this present work, the bioceramic composites, having the general formula [(100-x) (8 Mg-PSZ) – x (13–93 BG)] where x = 0 to 25 wt%, have been prepared and evaluated the effect of BG amounts on the machinability, mechanical and biological behavior of the composite material. The machining experiment is performed on an abrasive air jet machine (AAJM), and machinability is evaluated in the form of material removal rate (MRR), surface roughness (SR), and mechanics of material erosion (MME) at room temperature. The machinability results show that MRR decreases with enhancing the BG contents, and the SR follows the opposite trend of MRR. The MME indicates that the material is removed from the surface mainly due to the erosion crater and brittle fracture. Further, mechanical properties are evaluated, and it is found that the inclusion of BG frits and sintering temperature is substantially associated with the relative densities and the mechanical characteristics. Adding BG reinforcements increases the mechanical characteristics at lower sintering temperatures (1250 °C) while reducing the mechanical characteristics except hardness at higher sintering temperatures (1350 °C). Elastic modulus decreases with the addition of BG content up to 15 wt%; after that, it slightly increases up to 25 wt%. The in-vitro bioactivity and bio-degradation are tested in simulated body fluid (SBF), and both are increased by enhancing the BG contents up to 25 wt%. The in-vitro cell culture is performed on the MG-63 cell line. The biocompatibility increases with BG concentration (up to 25 wt%). Based on experimental results, it may be concluded that 8 Mg-PSZ/13-93BG bioceramic composites may be a potential choice for biomedical applications.

Regulation of the antibiotic elution profile from tricalcium phosphate bone cement by addition of bioactive glass

This work aimed at tailoring of different properties of antibacterial drug delivery Ca-phosphate cements by incorporation of bioactive glass (BG). The cements were prepared from beta-tricalcium phosphate cement (β-TCP) and BG based on 50 SiO2—20 CaO—15 Na2O—7 B2O3—4 P2O5—4 Al2O3 wt% with different percentages of BG [5, 10, 15, and 20% (w/w)]. The composite cements were characterized by XRD, FTIR, and TEM. Moreover, in vitro bioactivity and biodegradation were evaluated in the simulated body fluid (SBF) at 37 °C. In addition, physical properties and mechanical strength were determined. Also, the effect of glass addition on the drug release profile was examined using gentamicin. Finally, the antimicrobial activity was studied against Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumonia bacteria, one unicellular fungal strain (Candida albicans), and one multicellular fungal strain (Mucor racemosus). The results showed that after soaking in SBF, the compression strength values ranged from 14 to 36 MPa, the bulk densities and porosities were within 1.35 to 1.49 g/cm3 and 51.3 to 44.71%, respectively. Furthermore, gentamicin was released in a sustained manner, and BG decreased the released drug amount from ~ 80% (in pure β-TCP) to 47–53% in the composite cements. A drug release profile that is sustained by all samples was achieved. The antimicrobial test showed good activity of gentamicin-conjugated cements against bacteria and fungi used in this study. Additionally, cytotoxicity results proved that all samples were safe on MG-63 cells up to 50 µg/mL with no more than 7–12% dead cells. From the view of the physico-mechanical properties, bioactivity, biodegradation, and drug release rate, 20BG/β-TCP sample was nominated for practical bone grafting material, where it showed appropriate setting time and a relatively high mechanical strength suitable for cancellous bone.

Natural Polymers with Bioactive Glass Additives for Bone Regeneration: Chemistry and Trends

Abstract: Natural polymers, such as chitosan (CH) and gelatine (GE), have a wide range of uses in biological environments. This is primarily attributed to their biocompatibility and the body’s recognition of them being as “self” as opposed to “foreign”. These polymers provide a dynamic and cell-friendly interaction environment which is a crucial factor for tissue repair and regeneration. Bone regeneration is a highly intricate multistep process involving a plethora of biomolecules, signalling pathways, and stages in cellular activity. Critically-sized bone defects do not regenerate without an implant due to the cessation of the cellular stimulus associated with new bone formation. Therefore, natural polymers have been combined with bioactive glasses (BGs) to provide a biocompatible delivery matrix and to stimulate bone formation via the release of osteogenic ions from the BG particles. The addition of BG particles in natural polymers has been shown not only to result in an osteogenic response at a cellular level but also result in per se formation of hydroxyapatite (HA) on implant surfaces and regeneration of new bone in vivo. This review discusses the recent trends over the last decade in this field, keeping a focus on the chemistry and properties of CH and GE composites containing a bioactive glass additive.

Addition of Bioactive Glass Decreases Setting Time and Improves Antibacterial Properties of Mineral Trioxide Aggregate.

This study aimed to assess the effect of addition of bioactive glass (BG) on the setting time and antibacterial activity of mineral trioxide aggregate (MTA) against Enterococcus faecalis (E. faecalis). In this in vitro study, BG was synthesized by the sol-gel technique and added to MTA powder in certain ratios. Three groups of specimens were fabricated from pure MTA, MTA mixed with 10wt% BG, and MTA mixed with 20wt% BG. The setting time of specimens was measured according to ISO9917-2007. Direct contact test was used to assess the antimicrobial activity of the three groups against E. faecalis. Data were analyzed by repeated measures ANOVA (alpha = 0.05). Addition of BG (in both concentrations) to MTA decreased its setting time and improved its antibacterial activity against E. faecalis (p < 0.05). By an increase in concentration of BG (20%), the antimicrobial activity further improved (p < 0.05). Addition of BG to MTA in 10wt% and 20wt% concentrations decreased its setting time and improved its antibacterial activity against E. faecalis.

Glass modified Na0.5Bi0.5TiO3-based energy-storage ceramics for high-temperature applications at low/moderate electric fields

An innovative optimizing strategy via glass addition is proposed to lower sintering temperature through liquid sintering, which in turn triggers refined grains and boosts breakdown strength.

Low permeability sealing materials based on sewage, digestate and incineration industrial by-products in the final landfill cover system

This study explores repurposing municipal solid waste from the sewage, digestate, and incineration industries as landfill-sealing materials, aligning with circular economy principles. The main materials include digested sewage sludge (DSS), pretreated digested sewage sludge (PDSS), and digestate sludge (DS), with biomass bottom ash (BBA) and Al-anodizing waste (AAW) introduced as additives, complemented by 1.5 wt% water glass to enhance the sealing performance. The research evaluates the characteristics of the various treated and sourced sludges and additives, assessing their influence on water permeability, reaction products and the environmental consequences. Results demonstrate the achievement of low permeability in the sludge-based sealing materials, with optimal performance observed in the specimens prepared with DSS and AAW (k value = 3.78 ×10−12 m/s). Thermal Pressure Hydrolysis pre-treatment in sewage plants reduces the organic content in PDSS, resulting in a slight increase in permeability. DS-based specimens exhibit higher permeability due to their relatively lower organic content in DS. Gypsum is the primary reaction product attributed to leachable sulphate in BBA and AAW. Water glass addition in BBA-modified specimens promotes silica gel formation, while AAW effectively reduces matrix permeability as an externally added gel-like substance. Additionally, heavy metals (As, Pb and Cr) derived from the by-products are effectively immobilized in the sealing materials owning to the coagulation effect of organic matter in the sludge and sulphates in the products. Overall, this novel approach to landfill sealing materials exhibits promising applications in the Netherlands, offering cost savings and reduced environmental impact by recycling industrial by-products.

Metal-Organic Framework Glass as a Functional Filler Enables Enhanced Performance of Solid-State Polymer Electrolytes for Lithium Metal Batteries.

Polymers are promising candidates as solid-state electrolytes due to their performance and processability, but fillers play a critical role in adjusting the polymer network structure and electrochemical, thermal, and mechanical properties. Most fillers studied so far are anisotropic, limiting the possibility of homogeneous ion transport. Here, applying metal-organic framework (MOF) glass as an isotropic functional filler, solid-state polyethylene oxide (PEO) electrolytes are prepared. Calorimetric and diffusion kinetics tests show that the MOF glass addition reduces the glass transition temperature of the polymer phase, improving the mobility of the polymer chains, and thereby facilitating lithium (Li) ion transport. By also incorporating the lithium salt and ionic liquid (IL), Li-Li symmetric cell tests of the PEO-lithium salt-MOF glass-IL electrolyte reveal low overpotential, indicating low interfacial impedance. Simulations show that the isotropic structure of the MOF glass facilitates the wettability of the IL by enhancing interfacial interactions, leading to a less confined IL structure that promotes Li-ion mobility. Finally, the obtainedelectrolyte is used to construct Li-lithium iron phosphate full batteries that feature high cycle stability and rate capability. This work therefore demonstrates how an isotropic functional filler can be used to enhance the electrochemical performance of solid-state polymer electrolytes.

INVESTIGATION OF THE EFFECT OF WINDOW SHADES TYPE ON THE OTTV IN U COLLEGE BUILDING OF BANDUNG STATE POLYTECHNIC

The U building is the college building for the Department of Refrigeration and Air Conditioning, Bandung State Polytechnic. However, during the afternoon teaching, the third floor is often complained of feeling hot and disrupting the teaching and learning process. This is caused by the size of the window on the third floor is too large and does not use any shade. This research was conducted to determine the OTTV value of the existing U Building and then investigate the potential for improving the OTTV value by changing window glass materials or adding shading such as window film. This study used primary and secondary data collection methods. The primary data consisted of: building dimensions, glass dimensions, door dimensions, ambient temperature, inside temperature, wall and glass surface temperatures, and glass types. Meanwhile, some secondary data, namely building U as built drawings, wall specifications, and glass specifications used. It was found that the existing OTTV value of the Lecture U Building reached 39.78 W/m2 where this value was above the SNI 03-6389 2011 standard. By investigating the installation of shading such as window film and double glass it was possible to minimize the building's OTTV value to 36.78 W/m2 for window film and 33.86 W/m2 for the addition of double glass accompanied by window film.

Modulation of optical oxygen sensitivity of H2(TPP) by using Eu3+, Gd3+ and Yb3+ ions doped silicate-based bioactive glass powders immersed in simulated body fluid

Improving the performance of optical oxygen sensors can be accomplished by adding additives to the composition comprising an oxygen-sensitive probe encapsulated in a polymeric matrix. In this study, to advance the oxygen sensing ability, free meso-tetraphenyl porphyrin (H2(TPP)) was chosen as a luminophore. The sol-gel based 13–93 bioactive glass powders (BG) co-doped with ytterbium (Yb3+), gadolinium (Gd3+), and europium (Eu3+) and immersed in simulated body fluids (SBF) were also used as additives. After being immersed in SBF, bioactive glasses containing Eu3+, Gd3+, and Yb3+ were found to be able to convert hydroxyapatite corresponding to in vitro bioactivity tests. The optimum additive concentration for all glass samples is 3 wt%, based on photoluminescence-based properties. The luminescence dye was incorporated into poly(trimethylsilylpropyne) [poly(TMSP)] matrices in the form of a thin film along with bioactive glass additives to improve oxygen sensitivity. Emission-based intensity values of all porphyrin complexes have been followed as a signal drop during oxygen sensing measurements. The H2(TPP) along with the additive of BG:Eu3+ showed a 6.88 fold of I0/I ratio compared to the undoped and Gd3+ and Yb3+-doped BG forms in terms of the relative signal change. Large Stoke's shift (Ksv) values, high luminescence abilities, and linear spectral response make them promising candidates as oxygen sensing agents. It was concluded that prepared bioactive glass powders are suitable to use as additive materials for improving the oxygen sensitivity of meso-tetraphenyl porphyrin dye.

Temperature-stable Ba0.8Sr0.2CuSi2O6 microwave dielectric ceramics for LTCC application achieved with the addition of LBSCA and LBBS glass

Ba0.8Sr0.2CuSi2O6 ceramics have a low dielectric constant, which is useful for low-latency 5G communication. To enable the preparation of Ba0.8Sr0.2CuSi2O6 low-temperature co-fired ceramic (LTCC) materials, LBSCA and LBBS were used in this paper to reduce the sintering temperature of Ba0.8Sr0.2CuSi2O6. The effects of LBSCA and LBBS on the phase composition, densification, microscopic morphology, and vibrational characteristics of the ceramics were investigated by X-ray diffraction, scanning electron microscopy, density measurements, and Raman spectroscopy, and the causal factors influencing the microwave dielectric properties with the addition of glass were analyzed. It was found that 0.4 wt% LBSCA glass and 1 wt% LBBS glass reduced the sintering temperature to 925 °C, and these prepared ceramics had excellent microwave dielectric properties. The ceramic prepared with 0.4 wt% LBSCA glass had an εr value of 7.672, Q × f value of 37193 GHz, and τf value of −14.93 ppm/°C, while the ceramic prepared with 1 wt% LBBS glass had an εr value of 7.512, Q × f value of 32136 GHz, and τf value of −13.92 ppm/°C. The phase composition of the ceramics did not significantly change, indicating that neither glass reacted with the ceramics. The εr value was affected by both density and Raman shift, the trend in the Q × f values was consistent with the density, and the τf value decreased with increasing glass content, which was attributed to the liquid phase generated by the glass in the ceramic. In addition, co-firing these glass-doped ceramics with Ag at a low temperature resulted in good chemical compatibility. Combined with the near-zero τf, these results demonstrate the excellent promise of these two ceramics as alternative materials for LTCC microwave devices and their application in 5G communication.

Crystallization mechanism of B12.5 bioactive borosilicate glasses and its impact on in vitro degradation

Understanding the thermal properties and crystallization mechanisms are crucial upon sintering of bioactive glasses. In this study, crystallization mechanism and sintering ability of S53P4-based B12.5 borosilicate glass series, containing varying amounts of magnesium and/or strontium, was assessed. Additionally, the effect of crystallization onto these glasses bioactive properties was investigated.Glasses were composed of 47.12 SiO2 - 6.73 B2O3 - 21.77-x-y CaO - 22.65 Na2O - 1.72 P2O5 - x MgO - y SrO, where x,y = 0, 5 or 10 (mol%). Thermal properties were analysed with DTA, and glass transition temperatures and onset of crystallization were determined to gain an overview of temperature range suitable for heat treatments, and for calculation of activation energies related to viscous flow and crystallization. Further, sintered bodies were formed by heat-treating coarse glass particles in large temperature range; their porosity was assessed, cross section were analysed by SEM and crystallinity was studied with XRD. To evaluate the impact of crystallization on the in vitro reactivity, dissolution studies were executed in SBF-solution up to one week, with pH and ion content of solution measured at the end of immersion. Immersed particles were studied with FTIR to observe changes in the glasses structure.The main crystallization mechanism of B12.5-based glasses was determined to be surface crystallization. While the crystallization interfered with viscous flow sintering of the pure borosilicate glass, Mg and Sr addition enabled sintering of amorphous bodies more easily and with wider temperature range. Mg in the composition especially enabled densification. In vitro studies presented that surprisingly, partially crystallized specimen were initially more reactive than the amorphous specimen.

New insights into the effect of glass addition on the piezoelectric and thermal stability properties of (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 Pb-free ceramic by defect engineering of MPB

Lead-free piezoceramics with superior piezoelectric properties don't meet the requirements of practical applications due to their lower phase transition temperature and poor thermal stability. In the present work, we report a new insight into the effect of glass phase on the piezoelectric, Curie temperature and thermal stability of (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3 (BCZT) ceramic. Unlike traditional glass materials with more than 80% of B2O3 and SiO2 as glass formers, our approach is to fabricate a glass phase (Ba0.85Ca0.15)(Ti0.9Zr0.1)O3-0.05B2O3 (abbreviate BBCZT) with the same elements and concentrations as the ceramic phase. The ceramics-doped glass samples with the composition [(1-x)BCZT-xBBCZT], where x=(0.0, 0.025, 0.05, 0.075 and 0.1 wt%), were sintered according to the glass phase content. The effect of BBCZT glass composition on the crystal structure, dielectric, ferroelectric and piezoelectric properties of BCZT was investigated in detail. X-ray diffraction revealed that the addition of glass phase causes a defect engineering of the tricritical triple point of BCZT ceramic, where the tetragonal (T) and rhombohedral (R) phases were suppressed by the addition of glass phase and the T-phase has completely vanished at x = 0.05. The maximum value of permittivity (ε = 4102) and converse piezoelectric coefficient (d*33 = 1150 Pm/V) were achieved for the 0.975BCZT-0.025BBCZT sample at ambient temperature. Furthermore, the diffusion coefficient (γ) and Curie temperature (Tc) were observed to increase beyond x = 0.025, indicating enhanced thermal stability of BCZT at high glass content. These results qualify that the addition of (BBCZT) can enhance piezoelectric properties, phase transition temperature and thermal stability of BCZT ceramic which can meet wide requirements of practical applications.

Influence of Bioactive Glass Addition on TC4 Laser Cladding Coatings: Microstructure and Electrochemical Properties

There is a growing interest in enhancing the bioactivity of TC4-based metallic biomaterials, which are known for their excellent biocompatibility. Bioactive glass (BG) has been recognized for its high potential in promoting bioactivity, particularly in osteo tissue engineering. This study focuses on investigating the influence of BG addition on the microstructure and electrochemical properties of TC4 coatings. The TC4/BG composite coatings were fabricated through laser cladding, and their microstructure was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The electrochemical properties of the coatings were assessed through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests in three different solutions. The results revealed that the incorporation of BG had a significant impact on the microstructure of the TC4 coatings, leading to the formation of a well-defined interface between the TC4 matrix and the BG aggregates. The distribution of BG aggregates within the TC4 matrix coating was found to be random and unrelated to the specific regions of the coating. The metallographic microstructure variations were attributed to different heat dissipation conditions during the laser cladding process. Furthermore, the electrochemical corrosion behavior of TC4/BG composite coatings reveals that they exhibit stability similar to that of passive films and good resistance against media corrosion compared to TC4, while also showing enhanced corrosion resistance in 3.5 wt% NaCl and Dulbecco’s modified Eagle medium (DMEM) solutions, indicating their potential for biomedical applications; however, the corrosion resistance decreases gradually in all solutions, potentially due to the elevated Cl− concentration. Further research can explore bioactivity enhancement of TC4/BG composite coatings and investigate the long-term stability and biological response of these coatings in diverse physiological environments.

Eco-Friendly Coal Gangue and/or Metakaolin-Based Lightweight Geopolymer with the Addition of Waste Glass.

Massive amounts of deposited coal gangue derived from the mining industry constitute a crucial problem that must be solved. On the other hand, common knowledge about the recycling of glass products and the reuse of waste glass is still insufficient, which in turn causes economic and environmental problems. Therefore, this work investigated lightweight geopolymer foams manufactured based on coal gangue, metakaolin, and a mix of them to evaluate the influence of such waste on the geopolymer matrix. In addition, the effect of 20% (wt.) of waste glass on the foams was determined. Mineralogical and chemical composition, thermal behaviour, thermal conductivity, compressive strength, morphology, and density of foams were investigated. Furthermore, the structure of the geopolymers was examined in detail, including pore and structure thickness, homogeneity, degree of anisotropy, porosity with division for closed and open pores, as well as distribution of additives and pores using micro-computed tomography (microCT). The results show that the incorporation of waste glass increased compressive strength by approximately 54% and 9% in the case of coal-gangue-based and metakaolin-based samples, respectively. The porosity of samples ranged from 67.3% to 58.7%, in which closed pores constituted 0.3-1.8%. Samples had homogeneous distributions of pores and additions. Furthermore, the thermal conductivity ranged from 0.080 W/(m·K) to 0.117 W/(m·K), whereas the degree of anisotropy was 0.126-0.187, indicating that the structure of foams was approximate to isotropic.

Influence of Waste Glass Addition on the Fire Resistance, Microstructure and Mechanical Properties of Geopolymer Composites.

Nowadays, humanity has to face the problem of constantly increasing amounts of waste, which cause not only environmental pollution but also poses a critical danger to human health. Moreover, the growth of landfill sites involves high costs of establishment, development, and maintenance. Glass is one of the materials whose recycling ratio is still insufficient. Therefore, in the presented work, the influence of the particle size and share of waste glass on the consistency, morphology, specific surface area, water absorption, setting time, and mechanical properties of geopolymers was determined. Furthermore, for the first time, the fire resistance and final setting time of such geopolymer composites were presented in a wide range. Based on the obtained results, it was found that the geopolymer containing 20% unsorted waste glass obtained a final setting time that was 44% less than the sample not containing waste glass, 51.5 MPa of compressive strength (135.2% higher than the reference sample), and 13.5 MPa of residual compressive strength after the fire resistance test (164.7% more than the reference sample). Furthermore, it was found that the final setting time and the total pore volume closely depended on the additive's share and particle size. In addition, the use of waste glass characterized by larger particle sizes led to higher strength and lower mass loss after exposure to high temperatures compared to the composite containing smaller ones. The results presented in this work allow not only for reducing the costs and negative impact on the environment associated with landfilling but also for developing a simple, low-cost method of producing a modern geopolymer composite with beneficial properties for the construction industry.