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LaPO4 ceramic colorants were processed in the vibrant shades of green and brick red, and 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 it was 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 offers the stringent property, i. e., optical transparency and heat reflectance combined, when exposed to direct sunlight. 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.

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.

Herein, we report a green synthetic strategy for the preparation of ZnO@rGO nanocomposites. Bioinspired synthesis of ZnO nanoarchitectures has been done using a series of biotemplates such as dextrose, sucrose, soluble starch, and carboxy methyl cellulose. The as-prepared morphologically tuned ZnO nanoarchitectures are homogeneously distributed over the surface of rGO sheets, resulting in the formation of ZnO@rGO nanocomposites. For the first time, zinc (Zn) dust, a waste byproduct from industry (Binani Zinc Limited, Kerala, India), is employed for the chemical reduction of GO. ZnO@rGO nanocomposite based nonenzymatic urea and glucose sensors have been developed over a glassy carbon electrode, and the electrochemical performance of the nanocomposite for the detection of urea and glucose are investigated. The biosensor electrode is sensitive to urea in the concentration range of 0.02 × 10−3 mM to 7.2 × 10−3 mM with a detection limit of 0.012 μM. When used for glucose detection, the linear range is 0.02 × 10−3 mM to 18 × 10−3 mM, with a detection limit of 0.008 μM. The developed sensor exhibits an ultra-high sensitivity of 682.8 μA mM−1 cm−2 towards urea and 481 μA mM−1 cm−2 towards glucose.

A lanthanum based phosphate coating on magnesium AZ31 alloy was prepared through chemical conversion coating technique and characterized their corrosion performance. The coating was obtained in a two stage procedure using two different solvents, water or ethanol for preparing the coating nitrate bath. The chemical compositions and structures were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Corrosion performance of the developed coatings in 3.5 wt% NaCl was evaluated using electrochemical polarization and immersion tests. The results indicated that lanthanum hydroxide formation rather than lanthanum phosphate was predominant in the coating prepared using water as solvent for the nitrate bath whereas using ethanol as solvent produced lanthanum phosphate rich and defect less coating. An excellent corrosion resistance (in immersion test) was noticed with coatings prepared using ethanol as solvent (0.046 mm/y) over the bare sample (1.30 mm/y) as well as samples coated using water as solvent (0.278 mm/y).

LaPO

The increasing atmospheric temperature due to global warming demands development of coatings for glass windows that permits the light but not the heat. It is documented that the absorption of infrared radiations [IR] in the solar spectrum is the cause of heat build-up. Technologically it’s a challenge to have optical transparency and IR reflectance combined in a single-coat for any heat control cool-windows. Polymer coatings embedded with IR reflective ceramic dispersoids offer these stringent requirements, i.e light penetration and heat reflection when the glass panels are exposed to direct sun light. This current study focused on this concept. Here IR reflective rare earth colorant was first prepared and subsequently embedded in polymer resin to develop heat management coatings. The characteristic properties of the pigment as well as the coating were analyzed and were found that the inorganic dispersoids enhance the IR reflectance quality of polymer coats from 10% to 40%. The surface morphology, crystallinity and particle size of the product were also investigated. The inorganic-polymer composite coat offers thermal stability, light fastness and photo-physical properties

The present study elaborateson the gel assisted evolution of ZnO nanoparticles from zinc acetate and tartaric acid in aqueous and non-aqueous media. The effect of solvents and pH on the gelation characteristics were studied in zinc acetate and tartaric acid system and the ideal composition for the effective gelation is found out. The gelation processes were evaluated with respect to time using a rheometer and the various structural features of the gel were studied. The crystallographic,structural, morphological and functional features of the samples were studied with the help of X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and UV-Vis. Spectrophotometry(UV-Vis). The experimental parameters that decide the formation of

Novel hetero structured arrays of CdTe quantum dots capped ZnO nanostructures were successfully prepared through a three tier process. C-axis oriented ZnO nanostructures, namely ZnO nanox (where, x = discs, rods and wires), were prepared on glass and ITO substrates by employing simple, template free and low temperature solvothermal methods. CdTe quantum dots were synthesized subsequently through an organometallic route. ITO/ZnO NanoX/CdTe heterostructured arrays were finally developed, by capping ZnO nanostructured arrays with CdTe quantum dots by using 3-mercaptopropionic acid. The crystalline, structural, morphological and optical features of the individual nanostructures and the heterostructured arrays were investigated by using XRD, HR-TEM, SEM, EDAX, AFM, UV and PL. The role of solvents, solution concentration and temperature on deciding the final morphologies in solvothermal syntheses were studied and the possible growth mechanism of the different nanostructure arrays were proposed. The comparative electron transport studies of the ITO/ZnO NanoX/CdTe heterostructure arrays were carried out. Electrochromic display units having fast electron transport capabilities were developed. The study put forth many futuristic applications of these hetero structured assemblies in wide spectrum of scientific and industrial disciplines, particularly in the areas where a fast electron transport is required. Keywords: ZnO, CdTe, Heterostructured arrays, Solvothermal synthesis, Electron transport, Electrochromism

A facile multilayer hybrid coating with multifunctional characteristics like UV shielding, IR reflectance, photochromic and photoluminescence are designed with doped ZnO quantum dots [ZQDs] in PMMA polymer and proposed to fabricate solar radiation control active-interface layers. Sn and Ag doped ZnO quantum dots [ZQDs] were initially synthesized via a simple microwave assisted sol-gel strategy in the presence of 3-aminopropyl trimethoxy silane, a known organic capping agent. Doped ZQDs were assessed for the size, morphology, chemical nature, crystallinity and optical qualities. ZQDs were subsequently dispersed in methyl methacrylate monomer and polymerized in situ to obtain PMMA/ZQDs coating precursor sol. Multilayer hybrid coatings were then fabricated and examined for NIR shielding and UV absorbance efficiencies. Results indicated that the doped ZQDs/PMMA hybrid coatings have blue emission under UV light. With regard to NIR reflectance, the undoped PMMA/ZQDs hybrid coatings exhibit only spiropyran , is introduced in the doped ZQDs/PMMA hybrids, to display photochromic functionality with red emission. It is concluded that ZQDs doped with Sn and Ag ions once treated with organic dye molecule and inorganic co-activators, can result in an innovative photochromic, UV/NIR shielding solar-control interface coatings.

Undoped LnVO 4 and magnesium-doped Ln 0.95 V 0.95 Mg 0.10 O 4-δ (Ln = Pr, Sm, Gd, Dy and Er) orthovanadates were synthesized by solid state reaction method and characterized by XRD, SEM/EDS, electrical conductivity measurements in controlled atmospheres, and modified e.m.f. technique for determination of oxygen-ion transference numbers. XRD analysis showed the formation of phase-pure materials with tetragonal zircon-type structure and a decrease in lattice parameters with a decrease of ionic radius of rare-earth cations. Trace amounts of MgO and Mg-V-O phases revealed by SEM/EDS suggest that the solid solubility limit of magnesium cations in LnVO 4 lattice is somewhat lower than the nominal doping level, and that magnesium substitutes preferentially into the vanadium sublattice. LnVO 4 and Ln 0.95 V 0.95 Mg 0.10 O 4-δ orthovanadates show semiconducting behavior under oxidizing conditions at 450–950 °C and are predominantly oxygen-ionic conductors, except PrVO 4 that shows mixed conductivity. In the LnVO 4 series, electrical conductivity is the highest for PrVO 4 and SmVO 4 (~4 × 10 −4 S/cm at 800 °C) and decreases with increasing atomic number of rare-earth cation for the other compositions. Additions of magnesium results in a drop of electrical conductivity, by 1.5–2 times for most of compositions. Interstitial oxygen diffusion is discussed as a prevailing mechanism of ionic transport in undoped LnVO 4 , whilst acceptor-type magnesium doping suppresses the formation of interstitial oxygen ions. Humidity has a rather negligible impact on the electrical properties of substituted ceramics, indicating only minor (if any) protonic contribution to the total electrical transport of the studied orthovanadates.

Magnesium-substituted europium vanadate ceramics, Mg x EuVO 4 ± δ ( x = 0–0.5), were prepared by solid state method and characterized by XRD, SEM/EDS, dilatometry, UV–vis spectroscopy, impedance spectroscopy, and measurements of oxygen-ion transference numbers ( t o ¯ ). Magnesium was found to substitute preferentially into vanadium sublattice of zircon-type EuVO 4 with limited solubility of ∼5 at.%. Additions of magnesium increase slightly coefficients of thermal expansion (3.2–6.0 ppm/K at 150–400 °C) and have negligible effect on the optical properties. Undoped EuVO 4 is predominantly an oxygen-ionic conductor with t o ¯ = 0.96–0.99 at 700–900 °C under oxidizing conditions. Acceptor-type substitution suppresses total conductivity and oxygen-ionic transport. The variations of electrical transport properties are discussed in terms of interstitial oxygen diffusion in the parent EuVO 4 and oxygen vacancy diffusion in Mg-substituted vanadate. Humidified atmosphere has negligible impact on the electrical properties of substituted ceramics but results in increased electrical conductivity of EuVO 4 indicating a protonic contribution to the total electrical transport.

Metal to bulk metal oxide nanoparticles have been successfully processed via a sustainable, facile, and ecofriendly (green) approach, namely, aqueous mechanical-oxidation. Micron-sized zinc (Zn) dust (∼45 μm) was directly wet-milled using ceramic milling media for 72 h, resulting in the production of bulk monocrystalline ZnO nanorods (aspect ratio ∼5.2, hydrodynamic diameter of 315 nm) and voluminous H2 gas by catalyst-free water-splitting reaction. The mill-induced surface oxidation and the chemical purity of the synthesized nano ZnO were carefully studied using the XPS analysis. Other standard analytical tools were also employed to understand the crystallinity, phase purity, morphology, and surface area of the final artifact. The photocatalytic activities of these mechanically grown ZnO nanorods were ascertained from two cationic dye-degradation experiments, using the dyes methylene blue and rhodamine 6G. In a nutshell, the study throws a new insight into a cost-effective, zero-effluent, single-step, an...

This study investigated the role of poly-ethylene glycol (PEG) in the microwave synthesis of ZnO (ZPMx) nanorods. The molecular weight of PEG was found to strongly influence the aspect ratio of the synthesized material. The as-prepared ZPMx nanorods were post-grafted onto the surface of GO sheets using 3-amino propyl trimethoxy silane (APTMS) as a cross-linking agent to obtain ZPMx-Si@GO hybrid nanocomposites. Microscopic observations showed that ZPMx nanorods with different aspect ratios were evenly distributed on the surface of the GO sheets. It also showed enhanced thermal and chemical properties. The dependence of the antibacterial behavior on the aspect ratio of the ZPMx nanorods and GO was also investigated. An antibacterial assay was carried out using both the Gram-positive bacteria Staphylococcus aureus (S. aureus) and Gram-negative bacteria Escherichia coli (E. coli), and Klebsiella pneumonia (K. pneumonia). The results showed that the ZPMx-Si@GO hybrid nanocomposite had an excellent antibacterial property toward the test bacteria compared to pure ZPMx and GO. The synergistic effect of ZPMx and GO resulted in a superior antibacterial activity in ZPMx-Si@GO. Interestingly, the hybrid nanocomposite with a higher ZPMx aspect ratio (ZPM6000-Si@GO) showed excellent inhibition zones with diameters of ∼3.7, 3.1, and 2.4 cm corresponding to S. aureus, E. coli, and K. pneumonia, respectively. An optical density measurement, as well as the morphological changes in the bacteria, again confirmed the excellent bacterial growth inhibition of ZPM6000-Si@GO. The studies indicated that the ZPMx-Si@GO hybrid nanocomposite is a promising candidate for use in real waste-water disinfection.

Carbon dioxide adsorption capacities of amine modified sol-gel SiO2 mesospheres were evaluated. The sorbents were prepared from readily available sodium metasilicate via sol-gel process. Three amines were used for surface modification purpose, namely Tetraethylenepentamine (TEPA), Tetraethylenepentamine acrylonitrile (TEPAN) and a mixture of Aminopropyltrimethoxysilane (APTMS) coupled with the two amines individually. The sorbents were characterized and carbon dioxide adsorption studies at 50 and 75 °C were conducted. CO2 adsorption isotherms of the functionalized samples at both the temperatures showed that the sorbents coupled with APTMS gave better adsorption performance than with individual amines. The sample with mixture of APTMS and TEPA showed the best performance among the samples studied with a CO2 adsorption capacity of 3.26 mmol g−1 at 75 °C. The TEPAN immobilized sorbents exhibited faster kinetics at both the temperatures of 50 and 75 °C; henceforth it appears that in addition to the amine content present in the sample, effective distribution of the amines on the surface and inside the pores that are accessible to CO2 determine the actual working capacity of the adsorbent.

In this work, a lightweight inorganic-organic hybrid foam adsorbent is processed out of economically cheap "double-silicate" precursors employing natural bentonite and water glass through a facile cross-linking and polymerization technique. Poly(vinyl alcohol) was used to provide structural strength to the three-dimensional framework. The foam adsorbent possessed an apparent density of 0.083 g cm

Corrosion performance of magnesium phosphate composite coatings consisted of struvite (MgNH4PO4·6H2O) and newberyite (MgHPO4·3H2O) on magnesium AZ31 alloy obtained in a high concentrated NH4H2PO4 phosphating bath at different pH ranges in 1 wt.% NaCl aqueous solution were analyzed using potentiodynamic polarization test, EIS analysis and immersion test. The test results revealed that the corrosion performance increased with increase in the coating bath pH which could be attributed to the uniform and dense magnesium phosphate coating with fewer defects and increase in the content of insoluble struvite phase.

Hierarchically porous alumino-siloxane aerogels (ALS-PG) with a rare structural architecture were developed through a biotemplating method using pollen grains of Hibiscus rosa-sinensis. The unique structure of the Hibiscus rosa-sinensis pollen makes it an attractive biotemplate, by replicating all levels of macro- and mesoscale morphological features. The micromorphological analysis exposed funnel-shaped macrochannels between the mesoporous aerogel framework that are difficult to design artificially. The N2 sorption analyses confirmed hierarchical trimodal pore size distribution with an average mesopores diameter (ca. 3.9, 8.7, 26.6 nm), high BET/Langmuir surface area (497/664 m2 g–1) and large pore volume (1.6788 cm3 g–1) than the corresponding nontemplated aerogels and xerogels counterpart. Beneficial properties of this sophisticated hierarchical porous structure was examined and confirmed by the immobilization of steapsin lipase. Hierarchically porous ALS-PG showed enhanced loading and immobilization e...

‘Nanocoolants’ offering extraordinary heat transport property demand new and exotic nanostructures as fillers that can display enhanced thermal conductivity and thermochemical stability for efficient thermal management operations. Herein we report for the first time, the processing of stable MAXene nanofluids using 2D MAXene nanosheets derived from the bulk nanolaminated Ti 3 SiC 2 MAX phase ternary carbides via shear induced micromechanical delamination technique. The beneficial multifunctional physical properties of MAXene colloid such as thermal conductivity, viscosity and lubrication effect are assessed and reported. An enhancement of thermal conductivity by ∼45% is achieved at 323 K with a loading of 0.25 Vol% MAXene nanosheets. Interestingly, MAXene nanofluids exhibit decreased viscosity than the basefluid revealing that it can act as ‘rheo-controlled’ nanofluid. It is a unique rheological behavior, not exist in many well established conventional ceramic nanofluids. In addition, MAXene nanofluids also offer lubricating property with very low coefficient of friction (COF) values (

Ceramic–metal composite (cermet) varistor mixture was processed by mechanical blending of micron sized metallic Zn dust with rare earth oxides (La2O3, CeO2) and other varistor forming minor additives (CoO, Cr2O3, Al2O3, MnO2 and SiO2). Toxic Bi2O3 and Sb2O3 additives were avoided. The cermet varistor mixture was uniaxially pressed into cylindrical pellets and sintered at various temperatures to obtain ZnO varistors. At 1250 °C, Zn dust derived cermet composition showed 99% theoretical density, average sintered grain size

Thermo-mechanically durable industrial polymer nanocomposites have great demand as structural components. In this work, highly competent filler design is processed via nano-modified of micronic SiO2/Al2O3 particulate ceramics and studied its influence on the rheology, glass transition temperature, composite microstructure, thermal conductivity, mechanical strength, micro hardness, and tribology properties. Composites were fabricated with different proportions of nano-modified micro-composite fillers in epoxy matrix at as much possible filler loadings. Results revealed that nano-modified SiO2/Al2O3 micro-composite fillers enhanced inter-particle network and offer benefits like homogeneous microstructures and increased thermal conductivity. Epoxy composites attained thermal conductivity of 0.8 W/mK at 46% filler loading. Mechanical strength and bulk hardness were reached to higher values on the incorporation of nano-modified fillers. Tribology study revealed an increased specific wear rate and decreased friction coefficient in such fillers. The study is significant in a way that the design of nano-modified mixed-matrix micro-composite fillers are effective where a high loading is much easier, which is critical for achieving desired thermal and mechanical properties for any engineering applications. Copyright © 2016 John Wiley & Sons, Ltd.

Textile surfaces engineered with infrared/ultraviolet energy shielding coatings are an emerging technology in the processing of solar heat protective cool-textiles. In this work, such multifunctional coatings were prepared using silane treated nano ZnO hybrid embedded PMMA colloids on a model black colored cotton textile. Black cotton fabrics were selected for the study because they exhibit a high heat-build up tendency due to the inherent black body radiation effect. 3-(Aminopropyl)trimethoxy silane modified nano ZnO hybrids (APZO NHs) were first prepared and transformed into a stable colloidal dispersion in a PMMA medium to obtain an APZO NHs/PMMA sol. This hybrid–polymer colloidal sol was dip-coated on the fabric surface to form multilayer coatings. This surface engineered black cotton was subjected to studies of its phase analysis, chemical interaction, and morphological features in addition to its NIR reflectance, UV shielding efficiency and antifungal properties. The NIR/UV reflectance performance was analyzed with respect to the number of coatings and compared with the standard white cotton fabric which has roughly 50% NIR reflectance. When silane treated ZnO hybrid particulates are embedded in the PMMA matrix, the polymer coatings offer mechanically stable, UV/NIR radiation shielding textile surfaces in the wavelength region between 360 to 1600 nm that eventually turns the black cotton to cool-black textiles. The coatings also offer hydrophobic functionality as well as strong protection against the growth of Aspergillus flavus and Aspergillus niger fungi species resulting in biosafe textiles.

In this study an amine functionalized, mesoporous monohydroxy aluminium oxide (AlOOH/PEI) hybrid is prepared and further catalytically engineered with nano-CeO2 to make a multifunctional photoactive and antimicrobial catalytic-sorbent (CeO2@AlOOH/PEI). Structural and physico-chemical properties of this catalytic-sorbent were characterized using powder XRD, FTIR, SEM, TEM, N2 sorption analysis, TGA and zeta-potential measurements. This hybrid catalytic-sorbent is explored for the treatment of industrial waste water contaminated with lignin and organic dye. A comparative study was also done with other known conventional sorbents and the developed CeO2@AlOOH/PEI catalytic-sorbent shows a better adsorption capacity towards lignin. Photodegradation of lignin and methyl orange dye using the CeO2@AlOOH/PEI hybrid nanocomposite was also investigated under sunlight and UV irradiation. Both the pollutants show a better photodegradation under UV. Above all, the antibacterial properties of the CeO2@AlOOH/PEI sorbent were also studied against both Gram-positive (S. aureus) and Gram-negative (E. coli, K. pneumoniae) bacteria and showed efficient antimicrobial activity against these tested bacteria. An eco-friendly, self-regenerative, sustainable CeO2@AlOOH/PEI catalytic sorbent is designed and validated for the recovery of water resources from lignin and dye contaminated industrial effluent.

Multifunctional surface coatings hamper the UV/Near-infrared (NIR) radiations and resist ice/fog formation finds ready use in green buildings. Here, aluminium doped ZnO nano pigment (AZO) was synthesized and incorporated into poly(methyl methacrylate) [PMMA] polymer matrix to fabricate AZO/PMMA multilayered coatings on glass surface. Functional properties such as UV absorption, NIR shielding, self-cleaning, surface hardness and scratch resistance were assessed for AZO/PMMA coatings. Results revealed that AZO pigmented PMMA coatings shield UV and IR radiations in the wavelengths 363 and 1100 nm, respectively. Al-doping helps to enhance the NIR reflectivity in ZnO pigment. Coatings retain optical transparency only upto 20 layers. Interestingly, AZO/PMMA coated glass surface shows significant surface temperature cut-off upto 8 °C even with 7 layers. The coated glass found to have anti-icing property compared to uncoated surfaces when dipping in liquid N 2 . AZO/PMMA coatings can be an inexpensive interface/interphase layers for multifunctional glass windows.

Photoactive zinc based nanoplates were developed through a rapid microwave synthesis. A low temperature thermolysis reaction in a surfactant medium was initially performed for producing microwave active zinc based polar precursors. Using these precursors, the zinc oxide nanopowder having platelet morphologies were prepared. The nanoplatelets exhibited random growth with non-polar (1 0 1) surface as the major growth plane. The structural and functional features of the resultant zinc oxide samples were monitored using XRD, FTIR, TEM and PL. The photocatalytic activities of the samples were investigated through the standard photoreduction kinetics using the methylene blue dye. The catalytic efficiencies of the samples were checked both under UV and sunlight. A comparative study was also performed with the standard TiO 2 sample. The analyses revealed that the microwave derived zinc oxide have higher catalytic efficiency, than the standard titania samples, both under UV and sunlight illuminations. The unique nature of the zinc oxide non-polar surfaces can be attributed due to the presence of more active two dimensional open surfaces and the higher content of oxygen defect concentrations.

A facile aqueous synthesis has been reported for the preparation of organosilane treated ZnO nano architectures (Si@ZnO) via microwave strategy. An in-situ addition of 3-aminopropyl trimethoxy silane (APTMS) resulted in the formation of polysiloxane network that effectively controlled the exaggerated growth of ZnO finally produced high surface area, mesoporous Si@ZnO nano clusters. The formation of a polysiloxane network was confirmed from the FTIR analysis. Reduction in the crystallite size was verified from the powder X-ray diffraction and TEM analyses. Silane treated ZnO shows highly stable dispersion, in aqueous medium. The quantum confinement effect of size controlled Si@ZnO was confirmed from the blue shift in UV–vis absorption spectra. As a function of APTMS concentration both surface charge and surface area was found to enhance from (−12) to (+35.5) mV and 18 to 80 m2 g−1, respectively. Such positively charged Si@ZnO nano architectures showed property highly receptive to anionic dyes for the adsorption as well as photodegradation. In this study, size controlled, surface engineered, dual-functional photoactive adsorbent is successfully designed which is potentially useful for the recovery and recycling of dye contaminated water.

Exfoliated graphene oxide (GO) is catalytically activated via in situ growth of nanocrystalline ZnO crosslinked with 3-aminopropyltrimethoxy silane (APTMS) to result in ZnO/Si@rGO hybrid nanocomposite architectures. Structural and morphological features are systematically ascertained using XRD, SEM, TEM, TGA, UV-vis, FTIR and BET techniques. ZnO/Si@rGO hybrid nanocomposites exhibit a high surface area (78 m2 g−1). It is significantly large compared to phase pure nano-ZnO where the surface area is only 18 m2 g−1. Hybrid nanocomposite also shows ∼55% photocatalytic activity and ∼59% adsorption of dye from aqueous system containing 340 μM methylene blue (MB) dye. It was compared with pure ZnO, which shows only ∼0% adsorption and ∼31% photocatalytic activity. In the similar way, ZnO@rGO nanocomposites in the absence of a crosslinking agent were prepared and characterized. The adsorption and photocatalytic degradation property of both ZnO@rGO and ZnO/Si@rGO against the adsorption and photodegradation of a series of cationic organic dyes were compared for the first time. Interestingly, when ZnO/Si@rGO hybrid nanocomposite is deposited onto the surface of a cotton textile, it showed an excellent hydrophobic surface with a contact angle of 113.7°. Cotton textile modified with hybrid nanocomposite was explored further for the selective pick-up of engine oil contaminants from the aqueous media. The combined properties of dye adsorption, photodegradation and oil sorption properties of ZnO/Si@rGO hybrid nanocomposite enable the design of novel self-regenerative catalytically active cotton textile filters. A facile UV bleaching retrieves the cotton substrate for continuous use. In addition to this, ZnO–rGO composites were also prepared by a physical blending method and compared with ZnO/Si@rGO hybrid nanocomposite and ZnO@rGO nanocomposite.

A 2-dimensional ceramic nanostructure was successfully processed out of nanolamellar 312 MAX phase ternary carbide, titanium silicon carbide, Ti3SiC2 (TSC), via a simple shear-induced delamination technique. It has been explored as a functional nanofiller for obtaining chemically homogeneous, low-friction, self-lubricating epoxy nanocomposites. The structural characterization of the MAX phase Carbide Derived Ceramic Nanostructure (CDCN) was carried out using Dynamic Light Scattering (DLS), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) analysis. Subsequently, CDCN was mixed with Araldite CY 225 (DGEBA) at different percentages and thermally cured using Aradur HY 925 hardener at 130 °C to make epoxy–Ti3SiC2 nanocomposites. The effect of CDCN-nanofiller was studied on epoxy rheology, glass transition temperature (Tg), thermal stability, flexural and compressive strengths, microhardness, dry sliding wear and friction properties. It was found that, unlike other ceramic fillers, CDCN chemically interacts with epoxy and readily dispersed in a polymer matrix without any deleterious structural defects. It resulted in the formation of physico-chemically homogeneous microstructures. Epoxy composites prepared with CDCN filler attained 50% more mechanical strength and hardness. Wear analysis trends indicate Ti3SiC2 nano reinforcement possibly formed a lubricating tribo-chemical film that decreases the wear rate and coefficient of friction. This work is significant in such a way that a novel nanofiller has been identified from MAX phase carbide family which offers a self-lubricating interface and produces mechanically reliable, damage tolerant epoxy composite for state-of-the-art engineering applications.

Herein, we report the synthesis of ultrathin 2D Ti3SiC2 (MAXene) nanosheets via a facile shear induced micromechanical cleavage strategy. The very high dispersion stability, the UV absorption properties, high electrical conductivity and castability into thin films make the newly derived Ti3SiC2 nanosheets an ideal candidate for many functional applications.

This work describes a versatile strategy for the formation of thixotropically reversible alumino-siloxane hybrid gel suitable for the fabrication of open-porous aerogel like framework. Aminated alumino-siloxane gel was synthesized by pH controlled sol–gel assisted co-condensation of hydrolyzed aluminum isopropoxide with 3-aminopropyltrimethoxy silane. A rare reversible thixotropic flow behavior was noticed for the first time in aminated alumino-siloxane hybrid gel. The hybrid gel was used for preparation of hydrogel microspheres via gel granulation technique. The hydrogel microspheres derived from thixotropic gel showed an open porous network with intercommunicated structure. It was then converted to aerogel microspheres, without the collapse of the transient hybrid porous network by ambient pressure drying technique. The porous framework was tailored to hierarchical domains containing meso/macro porosity, with a dense array of functional amine on internal porous framework. The textural properties of the hybrid alumino-siloxane aerogel microspheres have been characterized by SEM, TEM, FTIR and N2 gas adsorption/desorption analysis and the results are discussed. Hybrid aerogel microspheres exhibit 2–3 times superior properties in terms of surface area and pore features compared to their xerogel counterparts. Thus, open porous aerogel microsphere derived from thixotropic gel could be a new media for controlling host–guest interactions especially when it is intended to be used in adsorption, separation and catalysis/catalyst support.

Surface functionalized multiwall carbon nanotube (MWCNT) reinforced teflon fibrils (MWCNT@Teflon) were successfully tested as an - oil - absorbent that can be used as a potential oil recovery material at the time of oil spill accidents in water. We found that oleic acid functionalization of MWCNTs was important for their adhesion onto teflon fibrils and at the same time prevented the MWCNT leaching into oil/water interface. The fibrils had displayed superior mechanical and thermal stability and provided a new insight to oil spill clean-up applications with easy recovery of absorbed oil by simple squeezing. Recycling of exhausted MWCNT@Teflon fibrils after oil recovery applications was conducted by pyrolysis under inert atmosphere in presence of magnetic clay. The magnetic clay absorbed the pyrolysis products, resulting in a heterostructured magnetic clay carbon composite (MCC) which was found super paramagnetic and chemically stable in all pH. The MCC was found capable of adsorbing textile dye from water ultra-fast with in a maximum contact time of 2 min and magnetically separable after adsorption experiments.

Correction for ‘Photoactive, antimicrobial CeO2 decorated AlOOH/PEI hybrid nanocomposite: a multifunctional catalytic-sorbent for lignin and organic dye’ by K. Aboo Shuhailath et al., RSC Adv., 2016, 6, 54357–54370, DOI: 10.1039/C6RA07836B.

The present chapter deals with a systematic report on ‘sol-gel ZnO varistors’, an area which needs to be much explored in terms of the applications it holds. The book chapter starts with a brief introduction on varistors. Subsequently, a detailed description on the so far adopted conventional preparation methods and chemical synthesis strategies for varistors are presented. Among the many chemical methods, the advantages of employing a sol-gel method for varistor technology are discussed in detail in later sections. A detailed literature survey on the preparation, properties and advantages of sol-gel derived ZnO varistors is provided. The main focus of the study is to highlight the importance of nanoinclusions for high-performance varistors in terms of controlled grain size, improved grain boundary area and homogeneous dopant distribution at the grain boundaries. The chapter concludes with a discussion on the recent research interests on the sol-gel ceramic–polymer varistors and studies on varistor-epoxy, ZnO-PANI, ZnO-PANI-PVA, GaAs-PANI-PE, Si–Polymer varistor composites.

Yttrium doped zinc oxide was prepared by microwave irradiation of Y (NO 3 ) 3 ·6H 2 O and Zn(NO 3 ) 2 ·4H 2 O as precursors, in ethanol–water medium. Highly polar ethanol–water medium (30/70, v/v) with hexamine and urea assist the formation of ZnO nuclei very rapidly in a specific fashion. Furthermore, Y 3+ ions infiltration into Zn(OH) 2 precipitate was facilitated by microwaves (2.45 GHz, 950 W). Yttrium doped nanocrystalline ZnO (ZnO-99 and ZnO-95) was formed with 1 and 5 mol% yttrium precursor. The powder was morphologically characterized with XRD, DLS, SEM and TEM. Photocatalytic activity of microwave treated Y 3+ doped ZnO was tested by studying the oxidation of methylene blue solution in a batch reactor. The studies showed that the catalytic reaction followed second order kinetics. Based on the results obtained from photocatalytic studies, efficiencies of various ZnO samples were found to be in this order: ZnO-A > ZnO-99 > ZnO-95 > ZnO-R that is, Y 3+ doped ZnO was not as effective as commercial undoped ZnO. However, ZnO-95 had shown better stability, antiphotocorrosive nature and reusability among the samples tested in this study.