Meso/microporous nano silica modified with macromolecular polymers produces attractive hybrids that repel water and have a hydrophobic surface, making them highly effective for targeting and eliminating organic contaminants in aquatic environments. In this study, nano silica was functionalized with silicone oil, an oligomeric siloxane derivative, to produce a hydrophobic silica nano hybrid characterized by a non-wetting water contact angle of 139°. This hydrophobic hybrid nano silica showed a sustainable floating nature on water even in turbulent streams. Due to such robust hydrophobic properties, the hybrid was explored for the separation of three different kinds of contaminants, such as (i) organic dyes, (ii) antibiotics, and (iii) nicotine. The concept of a floating sorbent has been innovatively introduced in this study through the application of silicone oil-modified nano silica. The adsorption experiments were systematically planned, and the data related to the percentage adsorption of contaminants with respect to dosage, pH, and concentration are reported. The results indicated an adsorption efficiency of >99% for cationic dyes with moderate adsorption observed for nicotine and antibiotics. The study highlights the significant potential of silicone oil-modified silica as a hydrophobic floating sorbent for environmental remediation. Buoyancy and strong water-repellent properties facilitate easy recovery and reuse, offering a sustainable and efficient method for the removal of diverse organic pollutants from water systems.

CO2 uptake using multifunctional, porous solid sorbents has gained significant attention due to their high thermochemical stability and selectivity. In this study, hydrophilic nanosilica was functionalized with blends of silicone oil and amines to develop hydrophobic silica sorbents capable of adsorbing CO2 at low temperatures in the presence of moisture. The adsorption performance of these sorbents was evaluated at 35 and 40 degrees C using silicone oil blends containing monoethanolamine (MEA), diethanolamine (DEA), and triethanolamine (TEA). Among these, the sorbent prepared with MEA, a primary amine, demonstrated the highest CO2 adsorption capacity. Further enhancement was achieved by functionalizing silicone oil with aminopropyltrimethoxysilane (APTMS). The optimized silica sorbent, with a 1:1 APTMS-to-silicone oil ratio, exhibited a maximum adsorption capacity of 0.75 and 0.86 mmol/g at 35 and 40 degrees C, respectively, and a water contact angle of 134 degrees, achieving an optimal balance between hydrophobicity and amine reactivity. Their enhanced adsorption capacity and structural resilience suggest applications where intermittent moisture exposure may occur, such as indoor air purification systems, industrial enclosures, and controlled environments like greenhouses or cabin spaces. The hydrophobic surface is expected to improve durability and minimize water interference in such applications.

Industries are progressively turning to sustainable alternatives due to rising environmental pollution and the depletion of fossil fuels. Over the past decades, significant efforts have been made to replace petroleum-based raw materials like phenol and formaldehyde with bio-based alternatives such as cardanol, derived from cashew nut shell liquid (CNSL). This study focuses on addressing the major limitation of crude CNSL—its dark brown color, which restricts its industrial utility. We have developed an effective and economical decolorization method using kaolin and metakaolin clays, examined for the first time as decolorization agents. By combining these clays with organic solvents, we achieved selective removal of the dark hue from CNSL. Hexane was found to be the most efficient medium, with a decolorization efficiency of 99

Polyurethane (PU) resin products meant for protective coatings are chemically composed of two-phase microstructures; soft ‘polyols’ and hard ‘diisocyanates and chain extenders’. For durable high-performance specialty PU coatings, their surface heat reflectance property is to be enhanced; otherwise, the absorption of solar heat energy eventually generates heat build-up that finally induces microstructural changes and chemical degradation. Hence, in this work, an attempt is made to improve the poor IR reflectance property of PU resin by incorporating kaolin micro-composite functional fillers. In this study, kaolin delamination was first carried out using alumina and zirconia milling media. Delaminated kaolin was treated with colloidal oxides, SiO2, Al2O3, and TiO2, to produce kaolin micro-composite fillers. The filler effect, chemical interaction, heat build-up, scratch resistance, and hydrophobic properties were examined, and results were presented. The study confirmed that when Al2O3-modified kaolin micro-composites improved the scratch resistance, the incorporation of 10 mass% mixed oxide kaolin micro-composite fillers enhanced the NIR reflecting property of PU coats from 4% to 53%. A facile strategy to enhance the solar heat shielding property of PU top coats for obtaining long-life durable protective coatings is presented in this work.

Nanocrystalline, non-metal (C, N, and S)-doped ZnO spherical clusters are successfully synthesized through a sustainable thermo-evolution method. Solar photocatalysts with high catalytic efficiency in the order C-ZnO < N-ZnO < S-ZnO are prepared.

Paper substrates possessing features ranging from hydrophobic to oxygen-barrier functional properties are gaining great attention recently due to the global ban on single-use plastics as well as the compulsion to avoid nonbiodegradable polymer packing. In this work, hydrophobic silica carriers are processed first through a direct physical impregnation of silicone oil in various amounts into the 20-nm sized silica nanoparticles and subsequently analyzed for the progressive changes in the surface hydrophobicity by water contact angle measurements. The hydrophobic nano-silica was also systematically analyzed by XRD, TGA, FTIR, SEM, and TEM and the results are presented. It was found that the nano-silica with the bulk BET surface area of 157 m2/g can accommodate 2.5 g of silicone oil per gram of silica, finally resulting in hydrophobic silica with a maximum contact angle of 139°. Later, this hydrophobic nano-silica was dispersed in a polymethylmethacrylate (PMMA) matrix and a coating formulation was prepared to develop water-repellent self-cleaning functional coatings on eco-friendly paper substrates. While applied as topcoats on paper substrates, the hydrophobic silica-PMMA gets embedded into the porous fibrous cellulose network and converts it into an impressive water-repellent packaging material with a contact angle of about 142°. This facile inorganic–organic hybrid topcoat strategy was successfully applied on the fibrous cellulose sludge waste produced by the paper mills to produce lightweight, water/moisture resistance packing material for circular economy.

Visible-light active anatase/brookite/rutile (A/B/R) ternary N-doped titania (N/TiO2) crystals are successfully prepared by a facile sol-gel method using titanium butoxide and benign N-dopant source, guanidinium chloride. Systematically varying the aging time (1, 4, 8, and 12 d), its influence on physicochemical properties of as-obtained spherical heterojunction nanomaterials is studied. Detailed characterizations confirm that a substantial amount of anatase (88% to 50%) is transformed to rutile (2% to 38%) via intermediate brookite phase (9% to 25%) as the function of aging time; not only the A/B/R phase content of the samples is tuned by sol-gel aging time of the precursors solution but also their optical-response and methylene blue photocatalytic properties are profoundly dictated. Notably under visible-light irradiation, the photostable rutile rich mesoporous A/B/R triphasic N/TiO2 (50% A, 12% B, 38% R) aged for 12 d demonstrates higher degradation activity (97%) with a faster degradation rate (0.033 min(-1)) than both lesser aged N/TiO2 and undoped titania. This enhancement is attributed to the synergistic effect of interstitial-N-doping and optimal A/B/R interfacial charge transfer that leads to higher light absorption, lower bandgap energy and well-separated charge carriers. The current work provides a new perspective for designing highly active visible-light heterostructure nanomaterials with controllable phase composition.

A2B2O7 type perovskite systems have found widespread use in various applications, owing to their exceptional thermal stabilities and adaptable lattice structure. La2Ti2O7 is one of the most studied system for optoelectronic and energy storage applications. The current work focuses on exploring the potential of La2Ti2O7 for developing ceramic colorants with near-infrared (NIR) reflective properties, ideal for energy-saving applications. Initially, co-precipitated La2Ti2O7 was calcined at different temperatures (600, 800 and 1000 degrees C) to realize the formation of phase pure perovskite structure. Further the composite ceramic colorants of La2Ti2O7 and Fe3O4 were developed via solid-state route at 600, 800 and 1000 degrees C. The phase purity and crystallinity of La2Ti2O7 and composite colorants were ascertained by the XRD analysis. The particle and chemical nature of the colorants were further characterized by SEM, TEM and XPS analysis. To comprehend the potential uses of these materials in different optoelectronic sectors, their tuneable optical band gap characteristics were determined. The NIR reflectance range of the synthesised La2Ti2O7 was found to be between 92 , 96 %, whilst the composite colorants showed values between 85 and 93 %. The influence of iron oxide doping and calcination temperature on the colour variations and photophysical characteristics of ceramic composite colorants have received special focus in this study.

Abstract UV filter agents are essential ingredients in cosmetics and fabrics for rendering the property of protection from harmful UV radiation. The focus of this research was on the development of biocompatible hybrid UV/IR filter agents through sol–gel processing of nano‐sized lanthanum titanate, zirconate, and phosphate‐based rare‐earth materials. 2‐Hydroxy‐1,4‐naphthoquinone (Lawsone) is an ideal candidate, owing to its biocompatibility, for treating the sol of the rare‐earth systems to produce inorganic‐organic hybrids with classical orange shades. The rare‐earth hybrids were characterized by X‐Ray diffraction, dynamic light scattering, fourier transform infrared spectroscopy, scanning electron microscopy, UV‐Vis, photo‐luminescence, and Near Infrared (NIR) spectroscopy. The results of characterization indicated that the hybrids offer >90% of NIR reflectance in the wavelength region from 700 to 1100 nm. They also exhibited excellent shielding in UV‐A and UV‐B regions, thus qualifying them as cool colors with useful optical as well as heat management characteristics. The sun protection factor calculated by optical density measurements showed that the synthesized hybrids have potential applications as UV filter agents in sunscreen lotions. The cell viability analyzed by the MTT (4,5‐dimethylthiazol‐2‐yl)−2,5‐diphenyltetrazolium bromide) assay affirmed the biocompatibility of the hybrids as none of the systems was found cytotoxic. This study was devoted to exploring the beneficial properties of rare‐earth‐based hybrid systems in pharmacological applications.

Pyrochlore-type rare earth ceramics are ideal for high-temperature coatings due to their exceptionally low thermal conductivity, high-temperature stability, and chemical inertness. To reduce the impact of urban heat island effect, ceramic colorants and coatings made of such materials are now required. The impact of iron oxide chromophore is investigated in this study on pyrochlore type lanthanum zirconate (La2Zr2O7) to make solar heat reflecting ceramic yellow colorant, and the same is then used for creating multifunctional glaze coatings. Using appropriate methods, the impact of iron oxide on the morphological, optical, and solar heat reflection properties of the yellow colorant is examined. The pyrochlore crystal structure and 93% NIR reflectivity of lanthanum zirconate were not impacted by the doping of iron oxide. Additionally, the glaze coating developed from the yellow colorant, surface non-wettability, NIR reflectivity, and tinting behavior were comprehensively examined and presented for the first time. The findings strongly indicated that pyrochlore La2Zr2O7 is a candidate to produce ceramic functional materials and coatings with sustained energy savings. This work opens up fresh possibilities for functional glaze coating applications using the pyrochlore type ceramic materials.

Photocatalysts are playing an indispensable role in tackling environmental and energy crises; however, they are associated with poor solar energy utilization. In this study, N-doped titanium dioxide (N-TiO2) nanocrystals were successfully prepared using benign N-source, guanidine chloride by simple sol-gel technique. The significance of annealing gases environment (air, argon, and nitrogen) on their physicochemical properties and photocatalytic activity under direct sunlight irradiation was investigated. XRD and Raman data revealed that the crystal structure of spheroidal N-TiO2 nanocrystals was transformed from monophase anatase with less crystallinity in argon, and nitrogen to dual-phase anatase/rutile (A/R) with higher crystallinity in air. Importantly, XPS confirmed the successful incorporation of N in interstitial sites of the bare titania structure. Moreover, DRS and PL results revealed that the introduction of N into the TiO2 matrix not only led to a red shift towards visible-light but also lowered the bandgap energy (2.35 eV) and suppressed charge carriers recombination. BET showed a typical IV isotherm of mesoporous N-TiO2 nanomaterials with a high specific surface area in the range of 80-103 m2 g-1. Furthermore, their rhodamine B (RhB) photodegradation performance and thermal-stability were dictated by the annealing gas type. Nobly, the N-TiO2 prepared in air demonstrated the highest degradation performance (99%) with the fastest rate (0.0158 min-1) which is twice faster as the control TiO2 material. Its real textile wastewater removal was 63% and 56.5% COD and TOC, respectively. These improved performances are mainly attributed to its higher crystallinity, A/R mixed phase, aqueous-dispersion character, and lower recombination rate. Such gas driven-synthesis of photocatalysts has practical applications in designing other solar energy conversion systems.

Scrap metals are a cost-effective secondary resource for producing functional metal oxides/hydroxides. Developing such functional hydroxides from scrap Mg via a low-energy, chemical-free process has high technological importance in the current scenario, as it emphasizes the 'waste to wealth' and green motives of production. This study presents an aqueous mechanical milling technique as a facile approach to yield functional grade nano Mg(OH)2 from industrial Mg crumbs. Formation of fiber-like nano Hy-Mg(OH)2 was confirmed on milling of waste metal scraps, by carefully controlling the mechanical parameters viz. the ball to powder mass ratio, milling medium, milling time, and milling speed. The optimized production of Hy-Mg(OH)2 was obtained after 90 h of milling, the evolution was confirmed using standard characterization techniques like XRD, TEM, and EDS. Flame retardant polyester/nano Hy-Mg(OH)2 composites were developed using casting technique. The developed polyester/nano Hy-Mg(OH)2 composites showed good flame retardancy, an oxygen index of ∼ 33% was obtained with 0.3 wf of nano Hy-Mg(OH)2 addition.

Pyrochlore-type rare earth ceramics are well-known for their exceptional thermal stability, low thermal conductivity, chemical non-reactivity, and mechanical durability. Functional ceramic colorants and glaze coats from such rare earth materials are currently needed to mitigate climate change and urban heat island effects. In this work, the effect of iron oxide chromophore is studied in pyrochlore type lanthanum zirconate (La 2 Zr 2 O 7 ) to produce solar heat reflective ceramic yellow colorant and subsequently the same is utilized for obtaining multifunctional glaze coatings. The effectiveness of the iron oxide chromophore in yielding the coloring characteristics, NIR reflectance efficiency, solar heat-shielding quality and also the non-wetting property of the ceramic glaze coats were systematically analyzed, and reported for the first time. The results on the NIR reflectivity, surface non-wetting property of the ceramic colorant as well as its’ glaze coat are strongly indicating the pyrochlore La2Zr2O7 is a candidate for making sustainable energy saving ceramic coatings. This study opens up a new vista on the application of pyrochlore type low thermal-mass rare earth ceramic colorants and multifunctional glaze coats.

Herein, we investigated the effect of a series of mono-substituted organotrimethoxy silanes (RTMS) on the sol-gel polymerization of hydrolyzed alumina sol (AIP) into a hybrid alumino-siloxane (AIP-RTMS) gels. RTMS with different organofunctional groups (R = methyl, vinyl, phenyl, octyl, aminopropyl, and glycidoxypropyl) were used for this purpose. The study revealed that the non-hydrolysable organo-functional groups of RTMS co-precursors strongly influence the gelation behaviour of AIP-RTMS hybrid gels. Evaporative and freeze drying methods were employed to obtain AIP-RTMS xerogels and cryogels, respectively. The remarkable variation observed in textural and morphological features of AIP-RTMS cryogels enabled them to possess greater surface area and pore-volume, and very low density than their xerogel counterpart. The study revealed that, the fissured arrangement of loosely layered morphology and non-hydrolyzable functional groups of RTMS in cryogels have a considerable influence on the surface wettability. Interestingly, a shift in hydrophobicity to superhydrophobicity was observed in AIP-VTMS and AIP-MTMS cryogels when compared to their xerogel counterparts. An excellent water repelling ability is also demonstrated using a fabric coated with AIP-VTMS hybrid. Owing to these beneficial properties, alumino-siloxane hybrids developed in this study have strong potential for the preparation of smart aerogels and coatings suitable in purification/separation applications.

Emulsion-combustion reaction was performed using cerous carbonate-urea emulsion prepared in hexane/water medium by mechanical milling with CTAB surfactant. Prolonged exposure of the urea-cerous carbonate emulsion mixture at 90 degrees C, undergoes slow and steady flameless, 'smouldering' that caused localized micro-thermal heating. Ultimately simultaneous decomposition of cerous carbonate and urea occurred, finally produced crystalline, soft ceria agglomerates consisting of fluorite CeO2 particles. Ceria thus obtained was studied for the optical reflectance in the wavelength 700-2400 nm to understand the total solar reflectance quality [TSR]. The product was also systematically characterized for phase purity, morphology, UV absorbance, band gap as well as surface chemistry using XPS analysis. The Near IR reflectance data confirms 94% reflectance in the IR region. Antibacterial and antifungal studies were conducted against Escherichia coli, Staphylococcus aureus, Klebsiella, Candida albicans, and Aspergillus Niger. Subsequently, this IR reflective, antimicrobial ceria was dispersed in an acrylic-sodium silicate hybrid dispersant cum binder system for ceria spray coatings on fabrics used for making face masks. The IR reflectance and hydrophobic properties of ceria coated masks were examined. This study explored the beneficial properties of IR reflective, antimicrobial, hydrophobic CeO2 for the processing of surface engineered, multifunctional textiles for the medical sector.

LaPO 4 ceramic colorants were processed in the vibrant shades of Green and Brick Red, subsequently embedded in polymer resins for the fabrication of heat management coatings. The IR/UV shielding characteristics of these ceramic colorants and polymer coatings were analysed and found that the ceramic dispersoids enhance the IR reflectance quality of polymer resins by 20 to 25 times. The nano ceramic green colorant reinforced polymer coating on glass panels offer the stringent property, i.e optical transparency and heat reflectance combined, when they are exposed to direct Sun light. Other photophysical properties were also studied and analysed. The brick red colorant entrenched resin coating on metal substrate offered heat reflectance and corrosion resistance characteristics. XPS studies provided the chemical environment of the systems. Surface morphology, crystallinity and particle size of the products were investigated using SEM, TEM, XRD and DLS techniques. The polymer resin coating of these ceramic colorants offers thermal stability and colorfastness properties.

Surface aligned, uni-directionally grown, hexagonal nanorod bundles and microrod pillared arrays of zinc oxide (ZnO), were synthesized through a simple, homo-epitaxial growth approach. A uniform layer of ZnO seed was initially prepared on cleaned glass substrates by dip coating and calcination. Uni-directionally oriented ZnO micro- nano structures were subsequently developed on the seeded glass substrates through solvothermal methods, by employing equi-molar solutions of zinc nitrate and hexamethylenetetramine. The reaction parameters that control the surface morphologies and crystal orientations were explored. A solution exchange process was also carried out to prepare perpendicularly aligned ZnO nanorod arrays. The structural and functional features of the resultant samples were studied and discussed with the help of X-ray diffractometry, scanning electron microscopy, high-resolution transmission electron microscopy and photoluminescence spectrophotometry. A plausible structure dependent growth mechanism of the morphologically varied ZnO was also proposed.

Jarosite, the byproduct obtained from zinc industry was resourcefully utilized for processing a series of ceramic hybrid dark colorants by incorporating selective compositions of metal and antimony. To explore and exploit the potential of this mineral waste as alternate colorants and generating secondary wealth, these jarosite colorants were subjected to optical properties assessment in the wave lengths region 200-2500 nm using UV-Vis, Near IR and photo luminescence. It is already known that the poor NIR reflectance of dark pigments poses a great challenge for converting them with high reflectance capability, the optical property measurements confirm that these jarosite derived dark colorants exhibit promising UV-Vis absorption as well as NIR reflectance. Interestingly, 43% of NIR reflectance was observed for Ag-Sb incorporated Jarosite (JSM 2) is the highest ever reported for black colorants. In addition to the optical property, the jarosite dark colorants were analyzed for the particle size, phase purity and morphology by employing DLS, Powder XRD, SEM and TEM techniques and the results are discussed. This unique study focused on the unexplored jarosite as well as the spectrally selective jarosite colorants for dark colored automobile coatings. (C) 2020 Elsevier Ltd. All rights reserved.