Silica Source Research Articles

Effect of silica source on photocatalytic properties of Bi2O3/Bi2SiO5 heterostructure

The Bi2O3/Bi2SiO5 heterostructures were obtained with various samples of silica as a precursor: on the basis of biogenic silica isolated from rice husk and rice straw and the silica of mineral origin. A mixture of Bi(NO3)3 and SiO2 with a mass content of 15% was used for synthesizing all the samples. Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), X-ray phase, X-ray fluorescence, and ultraviolet-visible diffused reflectance spectroscopy (UV-vis DRS) were used to systematically characterize as-obtained materials. Photodegradation of methyl orange in neutral aqueous solutions (pH = 6.8) under UV irradiation was studied to evaluate their photocatalytic activities. Morphology, bandgaps, the value of the zero charge point, and photocatalytic activity of the samples depended on the characteristics of the original silica. The degree of methyl orange degradation reached the maximum values (81%−85%) for samples based on precipitated silica from rice husks, straw, and the minimum value (16%) for a composite with thermal silica from rice straw. Composites based on thermal silica from rice husks and reagents from mineral raw materials did not statistically differ from each other in the degree of methyl orange degradation (67%−74%).

Mordenite-Type Zeolite from Iraq Sand: Synthesis and Characterization

Mordenite's excellent physical and chemical qualities set it apart from other zeolites with similar applications in industry. Mordenite is frequently produced through hydrothermal processing with TEA+ cations. The best template agent is TEA+ cations, despite the fact that they may lead to a variety of problems, such as the release of toxicity, the high cost of production, the contamination of wastewater, and environmental damage. So, it's important to develop a mordenite synthesis technique that doesn't need an organic template or a cheap template. The mordenite-type zeolites were prepared using sand from the western part of Iraq (Ar-Rutbah). Silica was extracted from Iraqi sand as a silica source and sodium aluminate as a source of alumina Al by using the SOL-GEL method through the hydrothermal technique at temperatures ranging from 23 to 27 °C over a period of 7 days. Analyses such as XRD, BET surface area AFM, FT-IR, and FE-SEM were performed on the sample. The average particle size was 31.9 nm, and the BET surface area was 202.487. XRF detected the ratio of silica to alumina (Si/Al = 4.55), and the exchange of sodium ions for hydrogen ions through ionic exchange is 100%. The micrograph clearly reveals a tiny portion of the crystal band with a flaky habit, while FE-SEM images of synthesized H-MOR show that plates form the majority of the crystals.

Triple silicon isotope insights into the formation of Precambrian cherts

Cherts are pervasive in the Precambrian and their O and Si isotopic compositions have been used extensively for reconstructing seawater paleo-temperatures. However, these reconstructions are obscured by the fact that cherts exhibit, at a given age, a large isotopic (O and Si) heterogeneity at bulk and micrometer scales. This is understood as reflecting the fact that cherts are an assemblage of silica precursors having different origins, and that diagenesis and metamorphism have modified the isotopic compositions acquired during the last equilibration with seawater. To test the contributions of the different processes that control the Si isotopic composition of cherts, we developed high-precision triple Si isotope measurements by Multicollector-Inductively Coupled-Plasma Mass-Spectrometer (MC-ICP-MS). This approach allows to identify deviations from the equilibrium Si isotopic fractionation at the level of a few ppm. Triple Si isotope data combined with trace elements and O isotope data in Precambrian cherts demonstrate that three different sources of silica were involved in the formation of cherts, and that both equilibrium and kinetic isotopic fractionation took place for Si. Archean seawater is predicted to have a triple Si isotopic composition kinetically fractionated relative to bulk silicate Earth. This requires a large kinetic isotopic fractionation during hydrothermalism of the oceanic crust and appears consistent with warm oceans in the Precambrian. However more work is required on the triple isotope systematics of Si inputs and output to seawater by rivers and authigenic clays formation. Triple Si isotope variations can thus be used as a new tool to unravel the origin of cherts and of their O and Si isotopic compositions. The present evidence of kinetic isotopic fractionations for Si isotopes also implies that Si isotopes should be associated to triple O isotope for paleotemperature reconstructions.

The effect of hydrothermal treatment conditions and silica source on the formation of cuspidine

The effect of hydrothermal treatment conditions and silica source on the formation of cuspidine

The effect of amorphous silica support on the catalytic activity of liquid-exfoliated monolayered MCM-56 zeolite

Recently reported groundbreaking discovery of efficient delamination of zeolite MCM-56, producing colloidal suspensions of MWW monolayers dispersed in the liquid phase, created unprecedented possibilities for the synthesis of a zeolite catalyst. Based on this innovation, the concept of using MWW monolayers to prepare silica-supported zeolite nanosheet catalysts suitable for transformations of large organic molecules was explored in this work. A series of silica-MWW preparations was synthesized from colloidal suspensions of the monolayers, using both solid and colloidal silica sources. The synthesized solids were thoroughly characterized with various physicochemical methods and their catalytic performance was tested in alkylation of mesitylene with benzyl alcohol. The obtained results indicate that solids containing MWW layers dispersed on silica show promising catalytic properties. The mixed MWW:silica catalysts synthesized from dispersions of MWW monolayers and liquid silica were found to exhibit high specific catalytic activity (with TOF values of 3.4 × 10−3 to 4.8 × 10−3 s−1), despite the high content of inactive amorphous silica support (40–60%). Materials synthesized from solid fumed and precipitated silicas showed low or negligible overall activity, which could be attributed to the small incorporation of the zeolitic active phase. For one of such materials, a notable high TOF (4.8 × 10−3 s−1) was found. It was found earlier that ethanol is an effective flocculent for zeolite layers by themselves, but in the presence of solid silica its efficiency was reduced.

Influence of Sodium Silicate, Sodium Aluminate, and Filicium Decipiens Charcoal on The Conductivity of Artificial Zeolite

Fly ash-bottom ash of coal is a solid waste in many industries and electric power plants. One method to reduce that solid waste is by using it to produce artificial zeolite. The Filicium decipiens charcoal was added into artificial zeolite to increase its performance to adsorb water pollutants. The pumice stone is also used in this work as a source of silica. The manufacture of artificial zeolite was carried out by the hydrothermal method by optimizing the composition of sodium silicate from Lampung pumice silica, sodium aluminate from aluminum scrap, and charcoal of Filicium decipiens. From the characterization of the LCR meter, the optimum artificial zeolite obtains the conductivity value from 9.14×10-6 (S/cm) to 6.09×10-6 (S/cm), confirming that artificial zeolite is a semiconductor material. The highest conductivity of artificial zeolite will increase its performance as a catalyst and absorbent. The composition of the artificial zeolite after XRF characterization was aluminum, silica, phosphorus, potassium, calcium, titanium, vanadium, chromium, Mangan, and ferrite. From the XRD characterization result obtained, the dominant phase is Zeolite-A. SEM-EDX characterization results obtained a spherical and cylindrical microstructure of artificial.

Effects of Different Silicon Sources on the Properties of Geopolymer Planting Concrete Mixed with Red Mud

In order to reduce the carbon emission of planting concrete in the process of preparation, and to realize the application of large amounts of red mud in the geopolymer, in this study, high silicon source materials and blast furnace slag are added to a large content of red mud base geopolymer planting concrete, which can remove the dependence of planting concrete on ordinary Portland cement and provide a new direction for the comprehensive utilization of red mud. In the paper, the effects of different A (Alkali solid content)/P (Powder dosage) and high silica sources (silica fume and diatomite) on the microstructure and fluidity of the geopolymer, as well as the compressive strength, pore characteristics, and alkalinity of the planting concrete, are comparatively evaluated. The corresponding results showed that when A/P was 0.25, the planting performance of the planting concrete would be reduced due to its high alkalinity; when A/P was 0.15, the planting concrete would have its sedimentation and the compressive strength decreased. On the other hand, the pozzolanic reaction among the silica fume, diatomite, and Ca(OH)2 significantly weakened the alkali pan phenomenon in the later stage of planting concrete formation. The addition of an appropriate amount of silica fume and diatomite also made the structure of the geopolymer more compact with better fluidity, which yielded superior pore characteristics and planting performance for the planting concrete. For good planting concrete pore characteristics, the test results showed that the fluidity of the mortar should be 112–128 mm. Overall, the best planting concrete performance was achieved at an A/P ratio of 0.2, with the contents of silica fume and diatomite being 10% and 5%, respectively. Furthermore, the slope finite element analysis showed that planting concrete made with red mud geopolymer had better slope protection potential than ordinary Portland cement.

Optimization of Biodiesel Production from Waste Cooking Oil Using a Green Catalyst Prepared from Glass Waste and Animal Bones

Biodiesel as a fuel has been shown to positively impact the environment; replacing or reducing the dependence on fossil fuels while providing a viable alternative. The use of waste oils, such as non-edible or used oils, can reduce competition with food, loss of resources, and the resulting higher prices. In this study, biodiesel was obtained by a transesterification reaction using used cooking oil from fast-food restaurants as the feedstock and catalysts from waste glass and animal bones as the silica and calcium oxide sources, respectively. Utilizing waste or non-edible oils for the production of biodiesel can lessen the competition with food sources while achieving environmental and ethical biofuel standards. Additionally, employing readily available waste oils and catalysts prepared from waste material is an economical and low-cost process compared to the use of conventional expensive feedstock and catalyst. The catalyst characterization for the prepared CaO–SiO2 catalyst was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FT-IR). The reaction was optimized using the response surface methodology (RSM) with central composite design (CCD) by varying three parameters: methanol-to-oil ratio, catalyst weight fraction (wt%), and reaction time. The highest biodiesel yield obtained using Design Expert software was 92.3419% at the optimum conditions of a 14.83:1 methanol-to-oil molar ratio, 3.11 wt% catalyst, and 143 min reaction time. This proved that waste cooking oil with CaO–SiO2 catalyst could be used in the transesterification process to produce a high yield of biodiesel, which was shown in the results obtained from the experimental runs.

The Strength, Microstructure, and ecological assessment of concrete mix incorporating waste glass powder and polypropylene fiber

Using waste glass powder (WGP) as a source of silica in the production of cement-based materials could form denser matrix and address the ecological challenge of its deposition. This study introduces two grades of fineness of WGP: fine glass powder (FGP) and ultrafine glass powder (UFG) as 5 % and 10 % substitution for cement in the production of concrete reinforced by polypropylene (PP) fiber. Nine concrete mixes are investigated for their mechanical and ecological performances. Additionally, the study of mixes’ microstructure is reported to observe the influence of WGP and PP fibers contributions on the hardened matrix. ‌Based upon the results, FGP incorporation significantly enhances the FRC compressive strength from 7 to 90 days (between 40 % and 60 %). However, the highest mechanical performance is achieved by 10 % UFG as cement replacement and 0.5 % PP fiber inclusion. Moreover, scanning electron microscope (SEM) results show more chemical activity of UFG, and less calcium hydroxide presented in the hardened matrix. In terms of ecological concerns, between 5 % and 10 % lower CO2 and SO2 emissions and water usage indices for proposed concrete mixes containing WGP, and PP fiber are obtained, while the required energy consumption for preparing these mixes significantly increases (around 15–45 %) due to UFG and PP fiber incorporation in FRC.

The solid-state reaction facilitated by a microwave-assisted method for lithium vanadium silicon oxide synthesis by incorporating pure silica and rice husk ash for the application as anode material in lithium-ion battery

A solid-state reaction: heated by the microwave-assisted method was used for the synthesis of Li3.6Si0.6V0.4O4 using LiNO3, V2O4, and (pure silica/silica from rice husk ash). In this work, the influence of the source of silica, and microwave heating time was studied on the electrochemical properties formation of the product. and electrochemical properties were measured by cyclic voltammetry. The substances were ground and heated with a microwave oven at 400 and 600 W for 5 min. Among the compound prepared from both pure silica and silica from rice husk ash with 600 W microwave heating provided the highest specific capacitance for both silica source supercapacitors at 444–616 F g−1 at the rate of scanning 5 mV s−1. Furthermore, the product from both silica heated with 600 W of microwave show a retention capacity of 88.8% after 300 cycles at a charge-discharge rate in the range of 0.1–5 C between 1 and 2.5 V. The result shows the specific capacity was 221 mAh.g−1, at 1 C discharge rate. To identify the empirical formula of the compound, X-ray diffraction and transmission electron microscopy were employed which suggested that the empirical formula was Li3.6Si0.6V0.4O4. The Fourier transform infrared and resonance Raman spectroscopy exhibited the bonds of Si–O, Li–O, VO, and Si–O–Si. The oxidation states of V for Li3.6Si0.6V0.4O4 and Li3VO4 in the products were verified to be V4+ and V5+ by X-Ray absorption near the edge structure. Scanning electron microscopy was employed for the porosity and crystal size of the product from rice husk ash precursor has a higher porosity and small crystal size than pure SiO2 precursor. These results suggested the Li3.6Si0.6V0.4O4 would be potential an anode in the lithium-ion battery.

Effect of green liquor dregs as an alkali source for alkali-activated blast furnace slag mortar

Sodium-rich green liquor dregs (GLD) are one of the main landfilled residues generated in pulp mills, and to date, no economically profitable ways to utilise GLD has been identified. In this study, GLD have been studied to be used as an alternative alkali source together with alkali-activator, sodium metasilicate (Na2SiO3), for blast furnace slag (BFS) mortar. Microsilica was used as an additional silica source to ensure steady Na2O:SiO2-ratio (0.16). In purpose to remove the remaining organic carbon and increase the suitability of GLD to be used in alkali-activated materials, it has been first thermally treated in 525 °C. The amount of GLD in the recipes varied from 0 to 45 wt%. Calorimetry measurements showed that increasing the amount of GLD reduced the hydration heat and postponed the reaction. With thermogravimetric analysis, X-ray diffractometry and scanning electron microscopy it was found that hydrated samples with more GLD contained more carbonate phases, which indicated that the reactivity of GLD was lower in comparison with that of other raw materials. Compressive and flexural strength measurements showed that increasing the amount of GLD affected the early strength gain (2 and 7 days) of the samples, but at the age of 29 days, the difference was not as high. The compressive strength of the reference sample at 29 days was 59 MPa, while the compressive strength of four sample recipes containing GLD (up to 36 wt%) was higher than 49 MPa. According to the results, green liquor dregs have potential to be used as a secondary alkali source in alkali-activated materials, but more detailed study should be conducted for the recipe in the future.

Use of rice husk as a source of silica for the production of self-flowing refractory castables

The objective of this study was: i) to obtain rice husk ash (RHA) with high purity silica for the production self-flowing refractory castables with different percentages of RHA as a partial substitute for microsilica; ii) analyze the mechanical, physical, thermal, and microstructural properties of the formulations studied in relation to the effect of firing temperatures. The rice husks were washed with acetic acid in autoclave, dried at 105 °C for 24 h and calcined at 600 °C for 4 h. The ashes obtained were analyzed by particle size distribution, X-ray fluorescence spectrometry (FRX), X-ray diffraction (XRD) and scanning electron microscopy with X-ray microanalysis (SEM-EDS). The presence of amorphous silica of high purity was verified with irregular grains and sizes between 40 and 145 μm. Refractory castables were produced by replacing 0%, 5%, 10% and 15% (mass) of the microsilica by rice husk ash. After curing, the specimens were dried at 110 °C for 24 h and a part was sintered at 800 °C for 5 h, while the other was sintered at 1430 °C for 8 h. The samples were submitted to tests of free creep; apparent density; linear variation; resistance to bending, compression and thermal shock. The formulation with the best mechanical performance, modulus of rupture (55.10 MPa) and compressive strength (119.62 MPa), was 10% replaced by rice husk ash and sintered at 1430 °C. This result was due to the formation of higher strength alumino-silicate phases and stronger bonds between the matrix and the aggregates. In addition, all analyzed materials using rice husk ash showed high density and good resistance to thermal shock, which is desirable for self-flowing refractory castables.

Comparative X-Ray Diffraction (XRD) Study on the Synthesis of Natural Based Magnetic Silica Nanoparticles

The aim of this study was to compare the synthesis process of magnetic silica nanoparticles (Fe-SNP) through the analysis of X-ray Diffraction (XRD) results. Fe3O4 magnetic nanopowders was synthesized by ultrasonic assisted co-precipitation and Fe-SNP was synthesized by direct mixing method of sodium silicate (Na2SiO3) and magnetite (Fe3O4) and the sol-gel method. Silica sludge was used as a silica source from Indonesia geothermal power plant waste. The synthesized of Fe-SNP is the functionalization of Fe3O4 with silica. Variations concentration of Na2SiO3 is used for the direct mixing method and variations of Fe3O4 form is used for the sol-gel method. Particles formed and particle size were characterized by XRD. The XRD results showed that there is no SiO2 phase in the sample synthesized by direct mixing method while two phases of SiO2 and Fe3O4 were found in the sample synthesized by sol-gel method. The size of the Fe3O4 nanoparticles calculated with Scherer’s formula and it obtained 19.9 nm, while the Fe3O4 nanoparticles with the addition of 20 mL and 6 mL Na2SiO3 concentrations were 6,53 nm and 10,23 nm. For the sol-gel method the size of Fe3O4 nanoparticles obtained was 11,03 using Fe3O4 powders and 9,86 using Fe3O4 solutions.

Effect of Titanium Dioxide Nanoparticles on the Properties of Poly(Vinyl Alcohol)/Silica Hybrid Films Prepared by the Sol-Gel Method

This work is focused on the preparation and characterization of poly (vinyl alcohol)/silica gel/Nano-TiO2, and the study of titanium dioxide (TiO2) nanoparticles (from 1 to 5%) on the properties of poly (vinyl alcohol) (PVA)/silica films. This new material was prepared by the sol-gel method using poly (vinyl alcohol) powder with Tetraethyl Orthosilicate (TEOS) as a precursor source of silica. TEOS was hydrolyzed and condensed in water and ethanol in the presence of hydrochloric acid (HCl) used as a catalyst. Fourier transform infrared (FT-IR), water absorption, water contact angle, ultraviolet-visible spectrometry (UV-VIS), and thermogravimetric analysis (TGA) were used to characterize the hybrid films obtained. The PVA/SiO2/Nano-TiO2 films were successfully synthesized. Owing to the FT-IR Analysis, the chemical bonds have clearly shown that the PVA backbone is linked to the (SiO2-TiO2) network. UV-VIS tests indicated that the hybrid films' UV shielding properties were drastically enhanced as a result of the addition of TiO2. According to the TGA tests, the hybrid films are more heat tolerant than neat PVA films. The water contact angle results revealed that TiO2 nanoparticles used as a doping compound possess an important influence on the hydrophilicity of PVA/SiO2 as thin films. The film's water resistance has also been enhanced.

Cyclic CO2 capture behavior of slag-derived Li4SiO4: A kinetic analysis of CO2 desorption

Two slag-derived Li4SiO4 were synthesized using metallurgical slags as silica sources and used as CO2 sorbents. The CO2 desorption process was studied using a fixed temperature during the sorption step, with different CO2 partial pressures and several desorption temperatures. The kinetic parameters of the CO2 desorption were studied using the Avrami-Erofeev and zero-order models. With the latter, it was possible to calculate the activation energy of the desorption during the first minutes of the process, while with the Avrami-Erofeev model, only the energy associated with the second stage of the model was obtained. The calculated energies with the Avrami model were at least three orders of magnitude greater than the sorption stages reported values. Moreover, both models showed that the Li4SiO4 derived from the electric arc furnace (EAF) slag is less dependent on temperature than the derived from the blast furnace (BF). The kinetic parameters of desorption were also calculated for several regeneration cycles, where it was found that the k values diminish when lower partial pressures of CO2 (PCO2) were used. Finally, the structural evolution after the cyclic study showed the formation of secondary phases in the slag-derived silicates.

Rice husk ash as an alternative soluble silica source for alkali-activated metakaolin systems applied to recycled asphalt pavement stabilization

Alkali-activated binders have been shown as a viable alternative do ordinary Portland cement. However, the development of lower carbon emission activators for this process is still a research-gap. The goal of this research was to analyze the stabilization of recycled asphalt pavement (RAP) mixtures with a metakaolin-based binder, alkali-activated by rice husk ash synthetized sodium silicate. Compaction, unconfined compressive strength (UCS), scanning electron microscopy (SEM), and X-ray diffraction (XRD) tests were conducted in stabilized RAP mixtures, submitted to different curing periods and temperatures. Also, results were correlated with the porosity/binder content index. Compaction results showed a reduction in dry unit weight as the RAP content increased for non-stabilized mixtures and a non-linear behavior for stabilized ones. For the UCS tests, the increase in binder content led to an increase in strength for all mixtures. High curing temperatures prevented the efflorescence phenomenon, however reduced strength due to crack formation. XRD analyzes showed the formation of minerals rich in silica and alumina, indicating the formation of geopolymerization products. Finally, the porosity/binder index was shown to be a viable dosage method to predict the strength of stabilized RAP mixtures.

A Systematic Review on the Synthesis of Silicon Carbide: An Alternative Approach to Valorisation of Residual Municipal Solid Waste

Over the past several decades, industrialised and developing nations have attempted to enhance sustainability. Demands for energy and the acceleration in environmental deterioration are the two primary obstacles to progress. The daily generation of municipal solid waste has been a significant factor in the deterioration of the ecology. To address this issue, a considerable amount of municipal solid waste may be used to synthesise SiC nanomaterials from organic and inorganic fractions and use them as carbon and silica sources. Nanomaterials have progressively received widespread prominence as the development of particulate materials accelerates at an incredible rate. One such material is silicon carbide (SiC), which has garnered considerable interest due to its remarkable performance and wide variety of applications. This review article discusses the SiC polytypes, including cubic, hexagonal, and rhombohedral SiC. The characteristics of silicon carbide, such as its biomimetic, surface, and thermal properties, are also discussed. In addition, the synthesis of silicon carbide was described in depth, including microwave sintering, the calcination method, the carbothermal redox reaction, and much more. The final section describes the applications of silicon carbide, including wastewater treatment, medical implants, and gas detection.

Pyro-Hydrometallurgy Routes to Recover Silica from Indonesian Ferronickel Slag

Ferronickel slag is a by-product of nickel smelting that provides an abundant silica source. Based on data, every ton of nickel production is equal to eight tons of ferronickel slag production, increasing without any recycling process. It is essential to create an end-to-end process for nickel production and its by-products because this would be a problem in the future and is relevant for many industrialized countries. This study describes a strategy to process ferronickel slag to produce silica. A pyrometallurgy–hydrometallurgy process and ferronickel slag were used to increase the silica content. The process was conducted through alkali fusion; the ferronickel slag was mixed with sodium carbonate at a temperature of 1000 °C for an hour and continued via leaching, precipitation, and cleaning processes. The leaching process was conducted with four concentrations (4 M, 6 M, 8 M, and 10 M) of sodium hydroxide and three different leaching durations (2 h, 4 h, and 6 h). Using hydrochloric acid (HCl) at pH 2 and deionized (DI) water cleaning, the precipitation process was adopted to synthesize a silica powder with the lowest agglomeration and enhance its purity. Characterization was carried out using X-ray Diffraction (XRD), Scanning Electron Microscopy–Energy-Dispersive Emission (SEM-EDS), X-ray Fluorescence (XRF), and Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES). This study highlighted silica characteristics that indicate high recovery by 85% through alkali fusion, HCl leaching, precipitation, and deionized water cleaning.

Development of clove oil based nanoencapsulated biopesticide employing mesoporous nanosilica synthesized from paddy straw via bioinspired sol-gel route

Paddy straw (PS) burning is a concerning issue in South Asian countries, clamoring for exploring alternative management strategies. Being a rich source of silica, PS can be a potential nanosilica (SiNPs) source. The current study reports a pioneering approach for green synthesis of high-purity mesoporous SiNPs by sol-gel method using the aqueous extract of Sapindus mukorossi seed pericarp as a stabilizer. The mesoporous nature of SiNPs was harnessed as a carrier for the essential oil to develop the carrier-based formulation. SiNPs were characterized using XRD, EDX, FTIR, FE-SEM, TEM, AFM, DLS, water contact angle, and BET analysis. The synthesized SiNPs possessed a spheroid morphology with an average particle size of 20.34 ± 2.64 nm. XRD results confirmed its amorphous nature. The mesoporous nature of SiNPs was confirmed using BET analysis which showed a cumulative pore volume of 2.059 cm3/g and a high surface area of 746.32 m2/g. The SiNPs were further loaded with clove essential oil (CEO), and the encapsulation of CEO was assessed using UV–Vis, FTIR, and BET analysis. The in-vitro antifungal activity of CEO and CEO-loaded SiNPs (CEO-SiNPs) was evaluated using the agar plate assay. UV–Vis results depicted 62.64% encapsulation of CEO in SiNPs. The antifungal efficacy of CEO-SiNPs against F. oxysporum exhibited minimum inhibitory concentration (MIC), i.e., 125 mg/L, while the MIC of CEO was found to be 250 mg/L. The study delivers new insights into the holistic utilization of PS and propitious contribution toward the circular economy and Sustainable Development Goals (SDGs).

Road Marking Glass Microspheres Fabricated from Rice Husk Ash

In this work, it is reported a comparison between solid microspheres produced from glass having conventional industrial sand (IS) and glasses made with rice husk ashes (RHA) as a source of silica. The same composition was used to fabricate both glasses. The focused was the production of glass microspheres for road horizontal marking, which would attend the type classification called Premix. The microspheres were obtained by the horizontal flame method. The results showed that characteristics such as production yield, morphology, granulometry and, mainly, retroreflectivity measurements are not altered when rice husk ash is present in the glass composition, showing that this can be a sustainable alternative material for this important application.