Increasing Silica Content Research Articles

Rice husk-derived self-healing superhydrophobic films using solvent-less approach for drag reduction and oil absorption behaviour

The present work focuses on a sustainable approach to transform rice-husk waste into self-healing superhydrophobic films with potential application for drag-reduction and oil absorption. Rice husk was transformed into amorphous nano silica particles (d50 ∼ 150 nm) exhibiting mesoporosity with a surface area of 400 m2/g. Superhydrophobic films fabricated using a solvent-less approach showed the transition from flattened to nano-globular morphology with increasing silica content in polydimethylsiloxane (PDMS), leading to exceptional superhydrophobicity. The optimized film with a particle fraction of 60 % exhibited high de-wetting (> 150º) and mechanical strength (∼7 MPa). The film showed extremely low water droplet adhesion of ∼19 μN, similar to lotus leaf owing to high negative Laplace pressure. Significantly, the film exhibited persisting de-wettability and endurance under harsh chemical, thermal, and mechanical conditions. The robustness is further fortified with room temperature self-healing and real-time self-regeneration characteristics, persisting even after exposure to strong acids and significant abrasion. The multidimensional aspects of the film embarked with a 70 % drag reduction and effective oil-water separation. The present work not only provides a sustainable pathway for managing agricultural waste but also a practical and easy-to-implement approach to tackle oil spill incidents.

Dry fractionation of chickpea flour: Impact of de-oiling and flow aids

Air classified chickpea protein concentrates often lack the separation efficiency of other starch-rich pulses. We subjected chickpea flour to de-oiling or to blending with different types and concentrations of silica flow aids to reduce its cohesion and to increase its dispersibility in air. Air classification enriched protein to a content of 45%. Initial protein yields below 25% increased to 70% upon extensive de-oiling, and this de-oiled ingredient containing 51% protein was enriched to 56% by electrostatic separation. Alternatively, nanosized flow aids doubled the initial protein yield. SEM-EDS image analysis revealed that higher silica concentrations increased the accumulation of nanoparticles onto flour particles, which lowered the flour's basic flow energy and moderately increased its dispersibility. This reduced fouling during air classification, but the protein yield levelled off with increasing silica concentrations because the microstructure was not disentangled further. Silica addition during milling rendered post-milling blending unnecessary, without compromising the protein yield.

(Invited) Electron Transport in Nanocarbon Networks for Energy Conversion and Storage Applications

Carbon nanostructures have attracted great attention in recent years as novel electrode materials in batteries with increased capacity and conductivity as well as enhanced material stability. In these nanostructures, nanocarbons such as carbon nanotubes and graphene nanoplatelets are interconnected to construct their three-dimensional networks around the host materials for Li deposition. This work focuses on the study of electron transport phenomena in these nanocarbon networks with two model material systems: (1) single-walled carbon nanotube (SWCNT) networks co-embedded with silica microparticles (Fig. (a)), and (2) free-standing three-dimensional graphene (3DG) structures with polymeric surface modifications (Fig. (b)). We characterize the materials for electrical conductivity and thermopower with varying material contents in the composites to reveal several key factors determining their energy-dependent carrier transport characteristics. It is found that in these three-dimensional nanocarbon networks, carrier tunneling at the junctions between nanocarbons along with the network morphology predominantly determines the transport properties. Simultaneous increase in electrical conductivity and thermopower is achieved for SWCNT networks co-embedded with silica microparticles by increasing silica content up to 40 w.t.% at a fixed CNT content. The enhanced electron transport is attributed to the reduced junction distances due to the intimate network formation on the surface of silica particles with a polymer binder. Our transport theory based on the Landauer formalism for junction tunneling reveals that the junction modification with polymer can alter the potential barrier heights for both electrons and holes at the junction to significantly change the transport properties of the composite. Doping of nanocarbons is also investigated for their impacts on the junction transport and the geometric factor of the networks. Finally, we also investigate the use of these carbon nanostructures in solid-state thermoelectric (TE) energy harvesters and ionic TE capacitors to harvest thermal energy from temperature gradients and fluctuations. Figure 1

Pre-structural patterning approach for enhancing flow characteristics of B-stage film-type epoxy molding compound

Epoxy molding compound (EMC) compositions of silica powder and epoxy matrix have been utilized as encapsulation for semiconductor packaging over the past decades. Among various forms of EMC, film-type EMC offers untapped potential. Utilizing EMC film as an encapsulation material allows larger and more uniform encapsulation behavior especially for panel-level and wafer-level packaging applications. In material aspects, as increases silica contents in EMC film, it can encounter a trade-off relationship between the coefficient of thermal expansion (CTE) and the material's viscosity. As silica content increases, the CTE tends to decrease, which enhances warpage behavior. However, viscosity also tends to increase, which reduces flowability. To overcome these tradeoff relationships, in our study, we have demonstrated a pre-structural patterning approach to enhance flowability of B-stage EMC film without changing the raw compositions of material. By doing that, we can suppose increased flowability of film while having similar thermomechanical properties. For patterning while maintaining B-stage, patterned protection film was fabricated using a brass-based metallic mold and a PDMS/PUA-based soft mold. Subsequently, pre-structural patterned EMC was fabricated by transferring the patterned protection film onto a B-stage EMC film using a laminator. The effectiveness of patterning on EMC film was investigated in both numerical and experimental molding analysis according to rheological, chemical, and thermomechanical characterization. The pre-structural patterning approach demonstrated enhanced flow characteristics via a shortened flow path despite the increased viscosity caused by higher silica content.

Insulating refractories based on rice husk ashes functionalized by flame-sprayed alumina coatings for steel ingot casting

This study investigates a new insulating refractory material based on rice husk ashes (RHA) for its application in the steel ingot casting process. The excellent insulating properties of this material may improve heat- and energy balance during ingot casting. A flame-sprayed alumina coating is applied to provide chemical inertness of the substrate material against the steel melt. The refractoriness, oxidation resistance, phase evolution and thermal expansion of four different grades of RHA materials and phase evolution and thermal expansion of flame-sprayed alumina coatings are studied. The refractoriness of the RHA materials increased with increasing silica content, showing sufficient refractoriness up to 1600°C for SiO2>94wt%. Immersion tests with composite materials made from RHA substrate and a flame-sprayed alumina coating were successfully performed in a steel casting simulator. No deformation of the substrate material nor spalling of the flame-sprayed alumina coating was observed despite an immersion without preheating.

Effect of hydrophobic nano-silica content on the surface properties of corn-starch films

Starch-based films can be used for applications such as single-use packaging for food with a short shelf life. Hence, starch-based films could be a green alternative to some plastic packaging. This study analyzes the influence of hydrophobic silica content on mechanical properties, surface free energy, surface roughness, and morphology of corn starch-based films. For this purpose, commercially available amorphous hydrophobic nano-silica, Aerosil® R972, was used. The lowest value of surface free energy was observed for the starch films with the lowest glycerol and silica content (57 ± 1 mJ·m–2 for CG40S2.5), while the highest value was with the highest glycerol and silica content (73 ± 2 mJ·m–2 for CG80S5.0). The influence of silica content on the tensile strength decreases and elongation at break was investigated. The results showed that the surface roughness increases when the silica content increases. The SEM and EDS observation confirmed the homogeneity of the developed materials. This study shows that the commercially available Areosil® type of silica can be successfully used to change the performance of starch films.

Absorbance enhancement of a treated Tanzanian kaolin for removal of synthetic dyes from contaminated water

Kaolin possesses unique features suitable for removing pollutants from aqueous solutions, in this regard, improving its effectiveness as an adsorbent is important. This study focused on refining the absorbance efficiency of Pugu kaolin clay from Tanzania to enhance its utilization in removing textile dyes from contaminated water. The process involved acid-activation after calcination at 750oC. Characterization using X-ray Fluorescence (XRF), X-ray diffraction (XRD), Attenuated Total Reflectance-Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Porosimeter techniques revealed the presence of kaolinite [Al2Si2O5(OH)4], silica (SiO2) and microcline [KAlSi3O8] as the main phases. Acid treatment resulted in an increase in silica content from 44.18% to 58.81% due to the appearance of tridymite, while alumina decreased from 26.70% to 12.74% due to the removal of kaolinite. Surface area significantly expanded from 15.36 to 149.61 m2/g as acid-soluble impurities were eliminated. Chemical composition was also altered, with a decrease in Fe2O3 and increase in other major oxides. The impact of acid activation on the adsorption capacity of the clay was investigated by studying various parameters such as contact time, temperature, adsorbent dose, initial pH and adsorbate concentration. Basic Blue 9 (BB9) and Direct Red 28 (DR28) dyes were used as model adsorbates. The results obtained at optimal conditions of 3 hours contact time, 27oC temperature, 0.9 g adsorbent dose, initial pH of 11 and initial adsorbate concentration of 90 mg/L, showed that acid modification of the clay increased its capacity to adsorb BB9 from 96.82% to 99.91%, and DR28 from 86.33% to 95.04%. These findings underscore the positive impact of modifying the raw clay, enhancing its suitability for dye removal applications.

Evaluation of Mechanical and Thermal Properties of Polypropylene-Based Nanocomposites Reinforced with Silica Nanofillers via Melt Processing Followed by Injection Molding

Polymer nanocomposites have been of great interest to packaging, energy, molding, and transportation industries due to several favorable properties including a higher resistance to stress and cracking even under flexed conditions, and also a chemical resistance to water, acids, and alkalis. The current work disseminates the studies on the mechanical and thermal properties of the polypropylene HHR102 polymer reinforced with nano dispersoids of silicon dioxide at varied weight fractions. The nanocomposites, fabricated via melt processing followed by injection molding, were tested for tensile strength, % elongation, tensile modulus, and impact toughness. Further, the samples were also subjected to dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) to determine the dynamic storage modulus and thermal stability. The addition of nano-silica in polypropylene HHR102 resulted in enhanced ductility and well-balanced tensile modulus; however, the tensile strength and impact toughness were found to be decreased. On the other hand, the storage modulus was significantly increased for all nano-silica (NS)-containing polypropylene HHR102 matrices. With the increased nano-silica content, the storage modulus was optimal. Further, with the lower weight loss of 30% and 50%, the thermal stability of the increased silica content PP nanocomposites was much affected. However, it improved at a weight loss of 30% for the lower silica content PP nanocomposite (PP-1%NS). The imbibition was found to increase with the increase in NS. The increase in imbibition is attributed to the micro-voids generated during ageing. These micro-voids act as channels for water absorption. Further, the degree of crystallinity of the nanocomposites was decreased as a result of inhibition by the nano-particles on the regular packing of polymer molecules. The structure–property correlations were explicated based on the achieved mechanical properties.

Impact of interatomic structural characteristics of aluminosilicate hydrate on the mechanical properties of metakaolin-based geopolymer

This study explores the influence of the interatomic structure of sodium aluminosilicate hydrate (N-A-S-H) with varying silica contents on the mechanical properties of metakaolin-based geopolymer. Geopolymer pastes comprising Si/Al ratios between 2.0 and 3.0 were synthesized. A larger number of Si-O-Si linkages compared to Si-O-Al linkages and a higher atomic number density were found in the geopolymers with higher silica contents, which enhanced the compressive strength of the geopolymer pastes up to the optimal Si/Al ratio of 2.5. The paste with a Si/Al = 2.5 exhibited a greater portion of Q4(1Al and 2Al) and denser morphology compared to the other geopolymer pastes. Furthermore, in-situ high-energy synchrotron X-ray scattering experiments were conducted to assess the elastic modulus of the aluminosilicate structure at a local atomic scale. The modulus value in real space decreases with increasing silica contents up to Si/Al = 2.5 and increases with the presence of excessive unreacted silica fume. The modulus value in reciprocal space for the axial and lateral directions both presented a positive value at the geopolymer comprising a Si/Al ratio higher than 2.5, indicating that the load-bearing property of N-A-S-H changed at higher Si/Al ratios. Moreover, the smallest difference between the strains along the axial and lateral directions was detected for the geopolymer with Si/Al = 2.5 in both the real and reciprocal space, owing to the most interconnected and flexible nanostructure, which led to the highest mechanical strength.

Preparation and characterization of acid-leached diatomaceous earth for application in the treatment of oily wastewater

This study evaluated the potential application of acid-leached diatomaceous earth in oily wastewater treatment. Acid-leached diatomaceous earth was prepared by treating diatomaceous earth using 2.2 M HNO3 to remove impurities. The leached diatomaceous earth was characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) analytical techniques to determine the crystallinity, elemental content, morphology and surface area, respectively. Response surface methodology (RSM) was employed to establish the optimum conditions on the treatment of oily wastewater using acid-leached diatomaceous earth. Elemental composition of acid-leached DE showed an increase in silica content reaching 91.57% from 78.98% and a decrease on elements such as CaO, K2O, MgO, and Fe2O3 associated with impurities such as carbonates and clay minerals. BET analysis showed an increase in pore volume and surface area from 60.88 to 68.71 Å and 15.02–22.40 m2/g following the acid leaching. The oil removal experiments revealed a maximum adsorption capacity of 124.16 mg/g and oil removal efficiency of 78.55% at an initial oil concentration of 3229.69 using 0.05 g adsorbent dosage and 119.20 min contact time. The adsorption kinetics data fitted better to pseudo-second order model (R2 = 0.98) of reaction kinetics indicating that adsorption occurred through chemisorption. The adsorption isotherms were described better by the Freundlich isotherms model (R2 = 0.87) indicating that adsorption occurred in a heterogeneous and multilayer surface. This study concluded that acid-leached DE has the potential for use in treatment of oily wastewater. However, further studies are encouraged to evaluate the regeneration and re-usability of the material.

Experimental Study of Influencing Factors on Mechanical Properties for New Coal-Like Materials

Physical similarity simulation is one of the best methods for improving coal bed methane extraction efficiency, and the development of reasonable materials is important for improving physical similarity simulation testing results. This study aimed to investigate the mechanical properties of coal-like materials in a solid–gas coupled physical simulation test experiment. A new type of material with sand as aggregate, cement gypsum as cement, and silica gel as adsorbent was developed by an orthogonal design method. ANOVA and theoretical analysis were used to investigate the sensitivity and effects of different content ratios on the volumetric weight, uniaxial compressive strength, and elastic modulus of coal-like materials. The results of the investigation showed that the order of volumetric weight sensitivity ranging from large to small was the contents of silica gel, gypsum, and cement. The order of the sensitivity of uniaxial compressive strength and elastic modulus ranging from large to small was the ratio of the contents of silica gel, cement, and gypsum. Furthermore, the volumetric weight, uniaxial compressive strength, and elastic modulus of coal-like materials increased linearly and exponentially with the increase of cement and gypsum contents, respectively, whereas they decreased exponentially with the increase of silica content. Based on the results and analysis, a comprehensive model for the characteristic parameters of coal-like materials was established, and the prediction error was controllable to within 25%.

Assessing diatom distribution in Cambay Basin, Western Arabian Sea: impacts of oil spillage and chemical variables.

Freshwater and marine diatoms produce the majority of the oxygen in aquatic systems. Estimates range from 12,000 to 30,000 species, and spatial distribution varies globally. There is significant variation in diatom diversity based on geographical and environmental conditions as well as the physicochemical characteristics of the habitat. Therefore, understanding the underlying factors that contribute to changes in diatom community structures requires a comprehensive understanding of taxons. A study of diatom assemblages from the Cambay Basin, Western Arabian Sea, was conducted, particularly on oil fields. A total of 37 samples were collected; nine were from oil fields. We evaluated micro-oil spills using Fourier transform infrared (FTIR) analysis and microscopic techniques. Correlations were established through the ordination analysis of pernicious physical and chemical water variables (BOD, COD, TDS, pH, temperature, and DO), including principal component analysis (PCA). The oil field sites showed more total dissolved solids (TDS) and chemical oxygen demand (COD) than the respective marine control sites. The study does not display a cause-and-effect relationship, but we observed a positive correlation between increasing silica concentrations and diatom growth in oil fields. In contrast, high aluminium concentrations in oil fields negatively impacted the growth of diatom assemblage and abundance. When surveyed in nine oil fields, we found that Gomphonella pseudosphaerophorum and Nitzschia palea are well adapted to oil concentrations up to 40 ppm.

Infiltration of silica slurry into silica-based ceramic cores prepared by selective laser sintering based on pre-sintering

The silica-based ceramic core is an important mold for manufacturing hollow blades. The preparation of silica-based ceramic cores by combining selective laser sintering (SLS) and vacuum infiltration (VI) technologies is a promising approach. To enhance infiltration effect, pre-sintering was introduced to obtain the bodies with high porosity and hydrophilicity. The infiltrated silica content increased from 29.58 wt% for samples infiltrated once to 68.91 wt% for samples infiltrated three times. The increase of silica content in the matrix reduced the porosity of final ceramics, thus improving the room-temperature flexural strength. The infiltrated silica gradually transformed into cristobalite during the high-temperature test, which improved the high-temperature flexural strength and creep resistance. When the final-sintering temperature was 1225 °C, room-temperature and high-temperature flexural strength reached 21.17 MPa and 21.21 MPa, respectively, due to the enhanced sintering necks and low porosity. These results indicate that our work provides a promising route to fabricate silica-based ceramic cores by SLS technology.

Wet-Dry Cycles and Microstructural Characteristics of Expansive Subgrade Treated with Sustainable Cementitious Waste Materials.

This work presents an experimental study on the physico-mechanical and microstructural characteristics of stabilised soils and the effect of wetting and drying cycles on their durability as road subgrade materials. The durability of expansive road subgrade with a high plasticity index treated with different ratios of ground granulated blast furnace slag (GGBS) and brick dust waste (BDW) was investigated. Treated and cured samples of the expansive subgrade were subjected to wetting-drying cycles, California bearing ratio (CBR) tests, and microstructural analysis. The results show a gradual reduction in the California bearing ratio (CBR), mass, and the resilient modulus of samples for all subgrade types as the number of cycles increases. The treated subgrades containing 23.5% GGBS recorded the highest CBR value of 230% under dry conditions while the lowest CBR value of 15% (wetting cycle) was recorded for the subgrade treated with 11.75% GGBS and 11.75% BDW at the end of the wetting-drying cycles, both of which find useful application in road pavement construction as calcium silicate hydrate (CSH) gel was formed in all stabilised subgrade materials. However, the increase in alumina and silica content upon the inclusion of BDW initiated the formation of more cementitious products due to the increased availability of Si and Al species as indicated by EDX analysis. This study concluded that subgrade materials treated with a combination of GGBS and BDW are durable, sustainable and suitable for use in road construction.

Corrosion protection of aluminum alloy 7075 using functionalized micro- silica based epoxy coatings

Composite coatings were prepared by using epoxy-hardener having a 2:1 composition and functionalized SiO2 having 0, 0.01, 0.03, and 0.05 proportion/s accordingly. Curing of the coatings on aluminium alloy 7075 substrates was performed at a temperature of 60 ± 5 °C. Moreover, corrosion assessment was carried out in 0.6M NaCl solution at room temperature. The outcome of Fourier Transform Infrared Spectroscopy (FT-IR) confirmed the presence of Si-O bond and epoxide peaks. XRD spectra depict that the intensity of AA-7075 peaks was substantially effected possibly due to more x-rays absorption in composite coatings as a result of increasing silica content. Electrochemical Impedance Spectroscopy (EIS) analysis depicted 116, 284, 620, and 1309% increase in charge transfer resistance (Rct) for 0, 1, 3, and 5% silica composition relative to bare AA-7075 samples. Moreover, potentiodynamic plots were used to estimate corrosion rate which depicted decline of 20, 55, 40, 90 and 97% when compared with pure AA-7075 substrate.

Geochemistry, Age, and Geodynamic Setting of the Volcanic Rocks of the Indigirka Section of the Uyandina-Yasachnaya Volcanic Belt (Northeast Asia)

The Uyandina–Yasachnaya volcano-plutonic belt (UYVB) is one of the largest structures of this type in Northeast Asia. It strikes in the north-west direction for 900 km from the upper reaches of the Kolyma River to the upper reaches of the Selenyakh River. The belt is characterized by the strong facies variability and zoning, which is expressed in a change from mafic volcanic rocks (Ilin’-Tass zone) in the northeast to felsic volcanic rocks (Darpir zone) in the southwest. Poor knowledge of the UYVB results in an ambiguous interpretation of its geodynamic nature and volcanic evolution. The paper presents new detailed geochemical, isotopic, and geochronological data on the volcanic rocks of the Indigirka section of the Darpir zone of the UYVB. The U-Th-Pb SIMS zircon dating showed that volcanic rocks of the section previously attributed to the Oxfordian–Tithonian stages have the younger age within 150 ± 2–152 ± 2 Ma, which corresponds to the Tithonian. Andesites from the section base show Ta–Nb depletion, indicator element ratios Th/Nbpm, La/Nbpm, and La/Smpm 1, and extremely low εNd = (–8), which may indicate a crustal contamination of mantle sources. Felsic volcanic rocks overlying the andesites have the postcollisional signatures. They are also characterized by the wide variations of εNd from –2.4 to –6.5 and model ages. The systematic position of the rocks in the section as well as upward increase of alkalinity and silica content from basaltic andesites to rhyolites in the upper parts of the section, which is typical of island-arc buildups, suggest that suprasubduction melts were generated beneath the collisional crust. Source of these melts could be a mantle domain that was enriched in fluid during previous subduction event.

A Future with Engineering Stone Made from Silica-Rich Iron Ore Tailings from Vale

Among the many initiatives being developed to recover and reuse mineral waste at Vale mining sites, the new business solution presented here uses silica-rich tailings as a substitute for primary silica to produce engineering stone products like kitchens countertop, bathroom vanities and floor tiles in a booming, multi-billion dollar industry. Engineering stone is an alternative to natural stone like granite. It is manufactured from approximately 93% primary silica, 7% resin, colour pigments and selected aesthetic additives, with the recipes varying depending on desired colour and aesthetic properties. Using primary (typically white) silica allows engineering stone manufactures to produce products with a wide colour range, so when used, residual (darker) iron ore in tailings can somewhat decrease colour control. Through innovative technological advances combined with a skilled and highly motivated workforce, Vale has been able to systematically improve separation efficiency of its concentration/beneficiation processes (primarily aimed at maximizing the recovery of iron ore). Fortuitous laws governing mass balances have ensured that increased recovery of iron ore in one stream has meant an associated increase in silica content of the other stream (tailings), in some strategic process streams as high as 90-96% SiO2. Such a systematic increase in the silica content (becoming whiter) has meant an increase in the colour control Vale silica-rich tailings can deliver the industry. Since 2014 Vale has been working closely with leaders in the engineering stone manufacturing industry to develop recipes. This collaboration is delivering engineering stone that not only meet EN 14617 industry standards for resistance to stain, strength and impact but also have colour ranges able to satisfy market needs.

Effect of silica on thermal and mechanical properties of eucalyptus-PVC wood-polymer composites

Wood plastic composites (WPCs) were prepared by extrusion molding with eucalyptus powder, polyvinyl chloride (PVC), and silica as additives. The mechanical properties, creep behavior, thermal properties, and cross-section microstructure of the composites were analyzed by universal testing machine, thermogravimetric analyzer, and scanning electron microscope. The results show that with the increase of silica content, the tensile strength, bending strength, and impact strength of the WPCs first increased and then decreased. When the silica content was 3.0%, the tensile strength, bending strength, and impact strength of WPC reached the maximum values of 27.5 MPa, 48.8 MPa, and 4.18 KJ·m-2, respectively, which represented increases of 12.6%, 9.4%, and 20.1%, respectively, compared with those without silica. When the stress was 13.4 MPa, the strain value of 3.0% SiO2-eucalyptus/PVC wood plastic composite was 3.3 times that of 4.46 MPa and 1.7 times that of 8.92 MPa. The pyrolysis process of eucalyptus/PVC WPCs showed a similar trend with different silica content.

Influence of Recycled Glass Ceramic Waste On Physical and Mechanical Properties of Foamed Concrete

Concrete is the most used man-made material and foamed concrete is a type of concrete widely known with high workability, low density and excellent thermal and sound insulation properties. Its global market has also been predicted to increase. Growing of population and economy, along with urbanization generate wastes which increase yearly. One of the solutions to reduce waste in landfills is by using waste in manufacturing. Glass, classed as a form of ceramic waste (GCW) has been left in the landfills unrecycled due to the challenges it causes. The primary purpose of this research is to find the optimal GCW composition as a quartz sand additive for Foamed Concrete-based Glass Ceramic Waste (FC-GCW) which will reduce the amount of unrecycled GCW that ends upin landfills while producing a sustainable product. The samples were prepared by grinding the GCW and mixing varying percentages of GCW (0, 5, 10, 15, 20, 25, and 30%) with a consistent quantity of cement, quartz sand, water, and foam. Physical (density, water absorption, porosity and Energy Dispersive X-ray (EDX)) test and analysis and mechanical (compressive strength) test were performed on the samples. During physical tests, the density increased as the GCW percentage increased, but water absorption andporosity decreased. FC-GCW 20% had appropriate density, water absorption, and porosity values of 0.887 g/cm3, 22.6 %, and 88.9%, respectively, which demonstrated that the material is lightweight and porous.For EDX analysis between FC-GCW control and FC-GCW 20%, it was found that when GCW was included, the weight percentage of Oxygen and Calcium decreased while the weight percentage of Silica increased, showing GCW increased Silica content, and pozzolanic reaction occurred to from Calcium Silicate Hydrate (C-S-H) gel.For mechanical testing, it was discovered that FC-GCW 20% had the highest average compressive strength of 0.94 MPa and 2.01 MPa for 7 and 28 days, respectively. This research's contribution can be applied to areas where low densities are preferred and low compressive strength is required, such as of road sub-base, fire breaks, raising floor level, void fill, harbour fill, bridge abutments and ground stabilization.

Biochar application enhanced rice biomass production and lodging resistance via promoting co-deposition of silica with hemicellulose and lignin

Biochar, an environmentally friendly soil amendment, is created via a series of thermochemical processes from carbon-rich organic matter. The biochar addition enhances soil characteristics dramatically and increases crop growth and yields. However, the mechanism by which biochar improves plant lodging resistance, which is heavily influenced by cell walls, remains unknown. Three rice cultivars were grown in an experimental field provided with four concentrations of biochar (10, 20, 30, 40 t ha−1). The biochar application enhanced biomass production and lodging resistance in all three cultivars by up to 29 % and 22 %, respectively, with the largest improvement at a biochar application rate of 30 t ha−1. Biochar application significantly enhanced stem cell wall-related characteristics, with an increase in stem breaking force, wall thickness, and plumpness of 52 %, 32 %, and 21 %, respectively, which are suggested to be major contributors to enhanced lodging resistance and biomass yield. Notably, cell wall composition and silica content analysis indicated a significant increase in hemicellulose, lignin, and silica content in biochar-treated samples up to 36 %, 13 %, and 58 %, respectively, when compared to plants not treated with biochar. Integrative analysis suggested that silica, hemicellulose, and lignin were co-deposited in cell walls, which influenced biomass production and lodging resistance. Furthermore, the transcriptome profile revealed that biochar application increased the expression of genes involved in biomass production, cell wall formation, and silica deposition. This study suggests that biochar application might improve both biomass production and lodging resistance by promoting the co-deposition of silicon with hemicellulose and lignin in cell walls.