NaNbO₃ thin films were deposited under different conditions by rf magnetron sputtering of ceramic target. Spectral transmission of the deposited films was measured in the UV-Visible-near IR range. Films deposited at 300 °C showed more absorption, and films annealed at 300 °C showed less absorption than those deposited at room temperature (RT), which was found to be consistent with their X-ray diffraction (XRD) patterns. From the observed transmission spectra, refractive index, optical band gap, absorption coefficient, extinction coefficient and film thickness were calculated for the deposited films. Refractive index at 550 nm wavelength was found to be 2.11, 2.01 and 2.34 for the films deposited at RT, 300 °C and annealed at 300 °C, respectively. The refractive index was found to be almost constant with respect to frequency for the films annealed at 300 °C. Optical band gap was found 3.82, 3.7 and 3.81 eV for the films deposited at RT, 300 °C, and annealed at 300 °C, respectively. Film thickness was shown to decrease with annealing. Absorption and extinction coefficients decreased with increasing wavelength, in all the samples. Band gaps associated with different interactions have been calculated for the deposited films. Phonon assisted indirect forbidden transition was most favorable in the deposited films.

Systematic investigation on the stability and electronic properties of a series of bimetallic (semiconductor-alkaline earth) clusters, viz., In_xMg₃ (x = 1 − 6) is performed, in the search for exceptionally and/or unusually stable motifs. A very popular hybrid exchange-correlation functional, B3LYP as proposed by A. D. Becke is employed for this purpose under the density functional formalism. The magic stability among the concerned clusters is explained using the jellium model. It is evident from the present study that the magic stability of In₄Mg₃ cluster arises due to the jellium shell closure and found as a potential building block for future novel semiconductor materials.

A series of nickel-doped barium cobalt hexagonal ferrite samples with chemical composition BaCo_2−xNi_xFe₁₆O₂₇ (x = 0.4, 0.8, 1.2, 1.6 and 2.0) were prepared using a simple heat treatment method. The dried precursor was calcined at 650 °C for 3 hours in a muffle furnace and slowly cooled to room temperature in order to obtain nickel-doped barium cobalt hexagonal ferrite powder. The prepared hexagonal ferrite powder samples were characterized using X-ray diffraction (XRD) and Vibrating Sample Magnetometer (VSM) techniques in order to study the effect of nickel substitution on structural and magnetic properties of barium cobalt hexagonal ferrites. The XRD analysis confirms the formation of mixed phases of W, M and spinel (S). The prepared powders exhibited single and multi-domain structures.

Nanocrystalline samples of CaWO4 were prepared at room temperature by simple chemical precipitation. The samples were characterized by X-ray diffraction and scanning electron microscopy. Energy dispersive X-ray analysis confirmed the elements present in the sample. The frequency and temperature dependence of the dielectric constant and ac electrical conductivity of the nanomaterial were investigated. Very low dielectric loss in nanocrystalline CaWO4 powder was observed at high frequencies. The values of ac electrical conductivity calculated from the permittivity studies were found to increase as frequency increased, conforming to small polaron hopping.

The 3D TiO₂ microflowers, sensitized by Bi2Te3 nanoparticles, having novel architecture were generated employing a two-step synthetic strategy, including a hydrothermal process and a potentiostatic electrodeposition technique. The design and synthesis of quantum dots (QDs) for achieving high photoelectrochemical performance is an urgent need for high technology fields

Composites of rotationally-moldable linear low density polyethylene (LLDPE) are becoming increasingly popular for rotational molding. In this study, the influence of fumed silica (FS) in pulling force requirement for demolding of rotationally moldable LLDPE is investigated. The dynamic mechanical analysis and creep studies were also performed to ascertain the reinforcement effects of FS in LLDPE matrix.

In this work we have investigated the frequency dependent dielectric properties of PrCrO₃ nano-ceramics using alternating current impedance spectroscopy. The material was synthesized by the sol–gel process. The Rietveld refinement of the X-ray diffraction data suggests single phase formation of the material with Pnma space group. The observed structure is substantiated by Raman spectrum of the sample. The ac conductivity follows the power law. The most probable relaxation frequencies at different temperatures were found to obey Arrhenius’ law.

The modification effect of bismuth (Bi) on in-situ-formed magnesium silicide (Mg₂Si) reinforced magnesium-aluminium (Mg–Al) alloy is investigated using optical microscope, scanning electron microscope and X-ray diffraction. Processing of the in-situ composite was carried out through a stir casting technique. The size of Mg₂Si is significantly refined and the optimal modification effect was obtained when the Bi content in the composite is 1.4%. A slight decrease in hardness values and increase in wear resistance were observed in the study with bismuth addition.

Titanium oxide (TiO₂) films were deposited on silicon (100) and quartz substrates at various substrate temperatures (300 – 873 K) at an optimized oxygen partial pressure of 3.0 × 10⁻² mbar by pulsed laser deposition. The effect of substrate temperature on structure, surface morphology and optical properties of the films were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM) and photoluminescence spectroscopy (PL) respectively. The XRD results showed that the films are polycrystalline in nature and have tetragonal structure. The film prepared at higher substrate temperature showed strong rutile phase. The results indicated that all the films possess both phases (anatase and rutile) of titania.  The AFM shows the crystalline nature, dense, uniform distribution of the nanocrystallites with a surface roughness of 2 –8 nm. The photoluminescence studies showed the asymmetric peak ∼ 370 nm indicating the bandgap for the TiO₂ films.

Zinc doped cobalt ferriteCo_1−xZn_xFe₂O₄ nanoparticles (x = 0.1,  0.5, 0.9) were synthesized by chemical co-precipitation method. The crystallite size, which was calculated from the full width half maximum (FWHM) value of the strongest peak (311) plane using Scherer approximation, was found to decrease with higher zinc content. The surface morphology of the powder samples was obtained using transmission electron microscopy (TEM). Magnetic properties, such as Saturation magnetization (Ms), Remanent Magnetization (Mr ) and Coercivity of the powder samples, were measured using Vibrating Sample Magnetometer (VSM) at room temperature and were found to decrease with increased zinc content.  Aqueous ferrofluids prepared from the powder samples were subjected to magnetic field to measure their Faraday rotation. Faraday rotation of the ferrofluids was found to increase with applied magnetic field and decrease with increasing zinc composition.

Nanostructured porous silicon (PS) samples were prepared by electrochemical anodic dissolution of doped silicon (p-Si) of (100) orientation at constant current density of 30 mA/cm² for different etching times 10 and 60 min. The samples were characterized by XRD and SEM. The particle size was calculated from XRD using Scherrer’s approximation are in the range of 12 to 61 nm and the SEM images confirmed the difference in porosities of the sample. The samples were sensitized with chloroaluminium phthalocyanine (ClAlPc) to fabricate Dye-sensitized solar cells (DSSCs). The bandgaps from UV- Vis and photoluminescence measurements are in the range of 1.5 to 1.8 eV. The photocurrent and photovoltage of the cells were measured using Keithely source meter. The maximum conversion efficiency of 2.8% is observed and results are discussed.

Nanostructured TiO₂ thin films were prepared for various thicknesses on fluorine – doped tin oxide (FTO) conductive glass by the spin coating method. Anthocyanin dye was used to sensitize the sample. The structural characterization was done by XRD. The bandgaps from UV–Vis and photoluminescence measurements are in the range of 2.41 to 2.59 eV. The photocurrent and photovoltage of the cells was measured using Keithley source meter. A maximum conversion efficiency of 0.27 % was observed and the results were discussed.

A glucose biosensor has been fabricated by using ZnS nanoparticle-substituted graphene nanosheets. Thermally exfoliated graphene nanosheets act as a suitable support for the deposition of ZnS nanoparticles. In this work, graphene was functionalized with ZnS nanoparticles by a simple chemical reduction method. The synthesized G/ZnS nanoparticles have been characterized using X-ray diffractometry (XRD), Transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), FT-IR techniques. Aditionally, the Glucose biosensor has been constructed by drop-casting G/ZnS over a conductive carbon support followed by the deposition of Glucose oxidase (GO_x) over a G/ZnS electrode. The performance of the biosensor was investigated by an electrochemical method. The resultant bioelectrode retains its biocatalytic activity and offers fast, highly-sensitive glucose quantification and a shelf-life of about 10 weeks under refrigerated conditions.

In this paper, the performance of a pentacene-based write once/read many memory device is reported.  The IV characteristics of a pentacene device deposited at 5 A˚ /s on an ITO-coated glass substrate was studied. This device showed a stable switching from ON to OFF state with an ON-OFF current ratio of nearly 10³ and a retention time of 5 × 10⁴ s with a switching threshold voltage of 3.9 V. The irreversible switching of this device makes it suitable for write once/read many memory devices.  The structural studies of pentacene thin films on glass substrate were also done and the dependence of device performance on grain size is reported. Improved performance of this device due to the addition of C₆₀ layer is also discussed.

Oxides of manganese have large number of applications in the field of sensors, piezoelectric crystals etc. In the present work, Mn₃O₄ nano materials were synthesized by using manganese acetate, adopting the method of thermal decomposition. The Nano materials thus prepared were characterized by employing various techniques like PXRD, FTIR, UV and Thermal analyses. The average particle size, calculated using Debye-Scherrer formula, was found to be in the range of 51 – 62 nm. The presence of Mn₃O₄ is also confirmed from FTIR. Thermal studies were also carried out. The optical band gap for the prepared nano materials was obtained from the UV-spectroscopic studies.

Frost formation and accretion on various outdoor structures like aircraft, wind turbines, heat exchanger coils etc. as well as on glass doors of indoor refrigerators is a serious issue as it presents economic as well as safety challenges. Most of the research done on anti-frost coatings is based on the theme of making the surface super hydrophobic (contact angle > 150 °, Sliding angle < 10 °) mimicking a lotus leaf which provides low or zero ice adhesion. Nanomaterials have played a significant role in such coatings as they help in tuning the surface properties which are surface roughness and surface energy. In this paper, we have tried to investigate why all superhydrophobic surfaces may not be ice-phobic and how nanomaterials improve super hydrophobicity of the surface, in turn, making them anti-frosting. This paper is a detailed study of anti-frosting strategies based on nanosystems which have been developed to date.

The objective of the existing research was essentially focused on recovery of MnO₂ nanoparticles from consumed dry cells by employing adapted hydrometallurgical process. Experimental tests for the recovery of MnO₂ present in the dry cell batteries have been carried out by an acidic reductive leachant, namely oxalic acid.  The elemental compositions of the recovered metals from dry cells were confirmed by Energy Dispersive X-ray analysis (EDAX). Surface morphology of the recovered metals was examined using Scanning Electron Microscopy (SEM). Phase composition of the recovered metals from dry cell batteries were confirmed from X-ray Diffract meter (XRD). Cyclic Voltammetry (CV) studies were carried out to clarify the reversibility of the reactions. The obtained MnO2 catalyst was applied for the degradation of different non-volatile dye compounds such as Indigo carmine (IC) and Rhodamine B (RB). The performance of MnO2 shows fast degradation of dyes of high concentration.

The objective of the research was mainly focused on the synthesis of ZnO and MgO nanoparticle by low temperature solution combustion method using Urea as fuel. The accurate size and morphology of the nanoparticles were studied from Transmission Electron Microscopy (TEM) to assess the structure of the ZnO and MgO particles. The phase composition of the Synthesized ZnO and MgO nanoparticles were confirmed from powder X-ray diffractometer (PXRD). The electrochemical impedance spectroscopy (EIS) shows the charge transfer capacity was more in the electrode with zinc oxide compared to magnesium oxide. Cyclic voltammetry studies were performed to ascertain the electrochemical reversibility of electrode.We evaluate the photocatalytic activity of nanoparticles shows rapid color removal and reduction in the concentration of dyes.

In the current study, chitosan films were prepared by dispersing different commercially-modified nanoclays, such as C-Na, C-10A, C-15A, C-30B, and C-93A. The exfoliation and morphology were studied using XRD and SEM. The C-15A, C-30B and C-93A nanoclays/Cts BNCs (Bionanocomposites) showed very good uniform exfoliation compared to that of other clays. The thermal analyses were evaluated using DSC and TGA. These results also confirmed that because of exfoliation, the thermal properties were improved in the case of C-15A, C-30B and C-93A nanoclays/Cts BNCs. The swelling capacity of a chitosan/clay films were studied. Increasing the chitosan content in the film increased the swelling capacity significantly; the decreasing order of swelling capacity of Cts/Clay films is in accordance with the decrease in clay content. Greater swelling capacity is shown by films Cts, C-Na and C-10A is because of the presence of greater hydrophilic agencies in the film makeup, which assist in improving the swelling characteristics of the films. The antibacterial activities of Cts/clay were also investigated against Gram-negative and Gram-positive bacteria (E. coli and S. aureus) according to the zone of inhibition in the disc diffusion method.

Superparamagnetism is an important physical property of a certain kinds of nanoparticles and these particles have attracted interest because of their applications in the technological world and medical fields. In this work, the author reports the synthesis of iron cobalt (Fe₆₀Co₄₀) and Manganese (Mn) incorporated FeCo compound nanoparticles by a simple inert atmosphere reductive decomposition method. The synthesized nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction technique (XRD), selected area electron diffrac- tion (SAED), energy dispersive X-ray analysis (EDX) and Fourier transform infrared (FTIR) spectroscopic method. The magnetic properties of the particles have been studied with a magnetometer (SQUID).

The objective of the current research was mainly focused on synthesizing the Reduced Graphene Oxide (RGO) using modified Hummers method and ZnO functionalized reduced graphene oxide (RGO) composite was fabricated by a one-pot approach. The ZnO functionalized graphene nanosheets were characterized by X-ray diffractometer (XRD) and surface morphology was examined using Transmission Electron Microscopy (TEM). Electrochemical characteristics of the ZnO/RGO composite were investigated through cyclic voltammetry and electrochemical impedance spectroscopy (EIS). The composite was capable of delivering a high specific capacitance with excellent cycling stability. The ZnO decorated RGO catalyst was also applied to degrade different nonvolatile compounds such as Methyl Blue (MB) and Indigo carmine (IC). The performance of RGO/ZnO shows rapid degradation of dyes of high concentrations.

Among electrochemical processes having a considerable impact on technical development, the mixed thin film (Mo-Ni oxide) plays an important role, due to its better mechanical, anticorrosive and thermal stability characteristics. The mixed films have been prepared by dip spin coating. The films are grown on substrates like Indium Tin Oxide (ITO) and are well adherent on the substrates, pinhole free and transparent. The X-ray diffraction analysis of the films confirms they are polycrystalline in nature. The morphological study reveals that the uniform distributions have flower-like structure. From the compositional analysis, the EDAX spectra show the presence of molybdenum and nickel. The optical band gap was found to be 1.36 eV and band assignments for Fourier Transform Infrared (FTIR) spectra are comparable to reported values.

Recently, transition metal oxides like Vanadium pentoxide have become a subject of intensive studies. The particular physical and chemical properties of these materials allow a wide range of practical applications such as electrochromic devices, cathode electrodes for lithium batteries, humidity sensors. The V₂O₅ film was prepared by an electrodeposition technique. The structural and optical properties were studied by X- Ray Diffraction (XRD), scanning electron microscopy (SEM), UV-Visible and Fourier Transform Infrared Spectroscopy (FT-IR). XRD spectra recorded has been observed and compared with the JCPDS values.  SEM images showed very smooth surface morphology and the elemental compositions of the film were confirmed by EDAX. The transmittance of the V2O5 films showed 75 % at 425 nm for the as-deposited substrate. The energy band gap of the films was found to be 2.45 eV and the band assignments of the V2O5 film are comparable with the reported values.

Nanotechnology-assisted organic electronics is a wide-spread and promising research field at present in the search for an efficient solar cell. The strong absorption spectra of the donor polymer poly[3-hexylthiophene-2,5-diyl)(P3HT) in the visible region and the prominent absorption of the acceptor [6,6]-phenyl C61 butyric acid methyl ester(PCBM) in UV region have proved them to be the most popular donor-acceptor pair for preparing photoactive materials. The active blend, having a broad absorption spectrum, is the primary requisite for an efficient solar cell. The present work is focused on optimizing the photoactive blend of (P3HT)) and PCBM for the maximum absorption of the solar energy. P3HT: PCBM blends of weight ratio 3:1, 1:1 & 1:3 were prepared in xylene as the solvent and glass coated samples are prepared by solution cast method. Samples were characterized by JASCO UV Vis NIR V 670 spectrometer. P3HT has strong absorption in the visible region, while PCBM has an effective absorption in the UV region with broad tail of absorption extending up to 800 nm. The spectrum for the blend is a superposition of the spectra of the component moieties. The 1:3 blend of P3HT with PCBM has broad spectral sensitivity for absorption and can be used as the best photoactive blend for construction of a plastic solar cell. The energy difference (band gap) between Highest Occupied Molecular Orbital (HOMO) and the Lowest Un-occupied Molecular Orbital (LUMO) of the samples were determined through Tauc’s plot. Calculations from Tauc’s plot indicated that pure P3HT sample has an onset wavelength of 640 nm with a band gap of 1.93 eV. The onset wavelengths for 3:1 & 1:1 blends are almost same of about 632 nm with a band gap of 1.96 eV. The optimized blend 1:3 sample has the onset wavelength 653 nm with the least energy gap 1.9 eV.The absorption by the blend can be further enhanced by either dye sensitization or plasmon resonance.

TiO₂, Ag and CuO nanomaterials, and nanostructured TiO₂/Ag/CuO photocatalytic materials coupled in different weight percentages were synthesized. The prepared materials were characterized by XRD, SEM, EDX and UV-Vis diffuse reflectance spectroscopy. Photocatalytic degrading capabilities of the pure, as well as the nanostructured TiO₂/Ag/CuO photocatalytic materials were tested on the dye effluent collected from the textile industries. The samples collected during the photocatalytic degradation of textile dye effluent were studied with UV-Vis spectroscopy. The nanostructured TiO₂/Ag/CuO photocatalyst with the composition of 80:10:10 weight percentage exhibited remarkable per- formance. Coupling of Ag metal nanoparticles and narrow bandgap CuO semiconductor nanomaterial to the wide bandgap TiO₂ semiconductor nanomaterial was found to modify the operative bandgap of the system and generate electron-hole pairs under visible light irradiation. The coupled TiO₂/Ag/CuO system facilitates improved electron transfer to the adsorbed molecules, and thus the system improves the photocatalytic degradation of dyes by enhanced redox mechanism.

Copper selenide was prepared by film is successfully deposited on a Fluorine-doped Tin Oxide (FTO) substrate by a brush plating technique. The film was uniform, had good adherence to the substrate and was annealed at 300 °C and 500 °C. As the annealing temperature increased, the orientation of the crystallites is more randomized than in the as-prepared film. The structural and optical properties of the film were investigated by XRD, SEM, EDAX, UV-Visible and PL. The XRD pattern indicated that this film was crystalline in the structure.

Tungsten selenide (WSe2) film was successfully deposited on FTO substrate by brush plating technique. The film was uniform and well adherent to the substrate and annealed to 300 ℃ and 500 ℃. As the annealing temperature was increased the orientation of the crystallites was more randomized than in the as-prepared film. The structural and optical properties of the film were investigated by XRD, SEM, EDAX, UV-Visible and PL. The XRD pattern indicates that this film was crystallized in the hexagonal structure.

Zinc oxide (ZnO) / Tin oxide (SnO₂) / Zinc stannate (Zn₂SnO₄) nanocomposite is prepared via hydrothermal route followed by calcination. The nanocomposite is characterized by X–ray powder diffraction, Fourier Transform Infrared spectroscopy and UV spectroscopy techniques. The nanocomposite’s morphology and the elemental composition is recorded using field emission scanning electron microscopy and energy dispersive X–ray spectroscopy analysis. The nanorods dispersed in the matrix of nanoparticles increases the surface active sites for gas adsorption and this material would be explored as a potential candidate for gas sensing applications at room temperature with quick response and recovery in the near future.

Titanium dioxide nanoparticles have been used to control corrosion of mild steel in well water in the absence and presence of an aqueous May flower extract. As the concentration of TiO₂ increases, the inhibition efficiency also increases. 100 ppm of TiO₂ offers 84 % inhibition efficiency. The addition of 10mlof May flower extract enhances the inhibition efficiency to 95 %. Adsorption of TiO₂ on the metal surface follows Langmuir adsorption isotherm. Polarization study reveals that the flower extract-TiO₂ system functions as mixed type of inhibitor, controlling both anodic and cathodic reactions. AC impedance spectra reveal the formation of a protective film on the metal surface. This technology may find application in cooling water systems and concrete technology.

Cashew nut shell wastes produced in cashew nut processing factories cause environmental problems. Currently, these wastes are being converted to a variety of bio-based chemicals and functional materials. Cashew nut shells (CNS) produce cashew nut shell liquid (CNSL), a dark reddish brown viscous liquid (ca. 30 – 35 wt. %) which is extracted from the soft honeycomb of the CNS. CNSL offers multitude interesting possibilities for the synthesis of speciality chemicals, high value products and polymers due to their functionalities. Our recent research have demonstrated that CNSL constituents can be transformed into diverse functional chemicals. This contribution will report on how cashew nut shells (an agro waste from cashew nut processing factories) have been employed to produce anacardic acid capped chalcogenide nanoparticles.

Cerium oxide (CeO2) nanoparticles were successfully synthesized by the hydrothermal method with different reaction times. The synthesized CeO2 nanoparticles were characterized by Powder X-Ray diffraction (XRD), Scanning Electron Microscopy (SEM), UV-Vis spectroscopy and FTIR spectroscopy. The effects of the reaction time on the structure and morphology of the prepared samples were investigated using XRD and SEM. The XRD studies reveal that the ceria nanoparticles have face-centered cubic structure. The SEM images reveal that the prepared Ceria nanoparticles are an aggregated form of spherical nanoparticles and the particle size decreases with increasing reaction time. FTIR analysis confirms the presence of CeO2 in the prepared samples. UV-Vis spectral studies show that the UV cut off wavelength decreases and the optical band gap increases with increased reaction time. Photoluminescence (PL) studies indicate that the PL emission of both the samples occurs at 683 nm, however, the emission intensity increases with longer reaction times.

In the present work, Polyaniline (PANI) and Polyaniline-Titanium dioxide (PANI-TiO₂) composite have been synthesized separately by chemical polymerization of aniline without/with TiO₂. Characteristic absorption bands of PANI and TiO₂ in the composite were confirmed by FT-IR studies, indicating the interaction of PANI with TiO₂. Comparative study of XRD patterns of PANI and the composite confirmed superficial deposition of PANI on TiO₂ and the average size of the composite particle was found to be 25 nm. The aggregated granular porous morphology of the composite was confirmed by its SEM image. The composite’s sensing response to humidity at room temperature was tested and was found to be 84.21 % in the range 25 % – 95 % RH. The response and recovery time of the composite at 95 % RH were measured to be 60s and 100s respectively and its sensing stability over a period of one month was also confirmed.

Zinc oxide - palladium nanocomposite material (ZnO-Pd)NCM was prepared and then characterized by UV-Vis spectroscopy, photoluminescence spectroscopy, X-ray diffraction analysis, energy dispersive X-ray analysis and field emission-scanning electron microscopy. The photocatalytic performance of (ZnO-Pd)NCM was investigated by degradation of Congo red under solar light irradiation. Zinc oxide modified with palladium metal could greatly enhance its photocatalytic activity and effectively degraded by Congo red dye.

Copper oxide is a narrow band gap, low cost, nontoxic, photoactive metal oxide and can be considered as the best candidate for photo- electrochemical applications. Thin films of p-type copper oxide are prepared by cyclic voltammetric technique.  The electrochemical method is a cost effective low temperature technique for the preparation of functional thin films. Tools like, GIXRD, Raman Spectroscopy, UV-Vis Spectroscopy, PL, SEM and EIS analysis are done to study the structure, phase, optical, morphological and electrochemical behavior of the copper oxide thin film. The effect of deposition conditions on the electrical and optical properties of the thin films are analyzed in detail.

The volatility of liquid electrolytes has been a major problem for their application in dye-sensitized solar cells (DSSC). In this study, liquid electrolyte was replaced by polymer based gel electrolyte. Polyvinyl alcohol is chosen as the polymeric matrix to gelate the liquid electrolyte with iodide-triiodide redox couple and suitable organic solvent. The amorphous nature and the physical cross linking formed between polymer- polymer and polymer-solvent is analyzed from XRD and FT-IR. Cell was fabricated and characterization was done. I-V and EIS measurements of the cell was taken. Easy fabrication and its advantages over liquid electrolyte makes gel electrolyte a promising alternative for liquid electrolyte.

Traditional strain sensors, such as metal foil gauges, can measure the strains only on the structural surface in designated directions and locations. Hence, there is a need to develop new types of strain sensors which can function on both the micro-and macro-scale, either on the surface or embedded in the structure, and able to behave as multifunctional materials. Owing to its outstanding electrical and mechanical properties carbon nanotubes (CNTs) can be used as strain sensing material. A film (Bucky paper/CNT network) made from multiwalled carbon nanotubes by use of solvent/surfactant and vacuum filtration method is used as strain sensor. The paper discusses the experimental work involving preparation of CNT film sensor specimen, its application on aluminum and brass strips along with conventional foil gauge and subjecting the metal strips to axial loading to measure gauge factor. It was found that CNT film strain sensor shows linear relationship between change in resistance and strain. Furthermore, the gauge factor increases as the film aspect ratio increases, and for the same aspect ratio, a higher gauge factor was observed for brass than aluminum.

A simple green method was developed for the synthesis of silver nanoparticles in the presence of a neomycin-functionalized chitosan as stabilizing agent using a fresh lemon juice as green reducing agent. The stabilizing agent was synthesized based on the Schiff base formation reaction between the chitosan dialdehyde and neomycin antibiotic in 0.05 mM at pH 7.0. The combined form of neomycin antibiotic with chitosan can be used as stabilizing agent for silver nanoparticles (AgNPs) synthesized by a biogenic method using lemon juice as a green reducing agent. The neomycin functionalized chitosan stabilized AgNPs were characterized by various analytical techniques, including UV- Visible spectra studies, FTIR, XRD and SEM. The antimicrobial activity of these composite was tested against human pathogenic Gram-positive and Gram-negative bacteria. The synergetic effect of the neomycin functionalized chitosan protected silver nanoparticles was tested against various drug resistant microorganisms. These chitosan derivatives can be used in combination with an anti-bacterial agent to treat and inhibit a resistant bacterial infection or the growth of resistant bacterial infection.

In the present investigation, we have successfully synthesized nanocrystalline bismuth selenide (Bi2Se3) thin films using an arrested precipitation technique at room temperature. The optostructural, morphological, compositional and photoeletrochemical properties were studied for Bi2Se3 thin films prepared via surfactant-assisted synthesis. The optical study reveals the presence of direct allowed transition with band gap energy ranging from 1.40–1.80 eV. The X-ray diffraction (XRD) pattern confirms rhombohedral crystal structure. Scanning electron microscopy study shows the morphological transition from an interconnected mesh to nanosphere-like morphology and finally, lamellar sphere. Atomic force microscopy (AFM) study carried out to determine surface roughness and surface topography of thin films. Energy dispersive spectroscopy (EDS) analysis reveals the presence and ratio of elemental bismuth and selenium. Finally, the photoelectrochemical (PEC) performance of all the as-synthesized thin films were carried out using iodide-polyiodide redox couple.

Zeolite Y is a cage-like alumina silicate which is widely used as solid support to immobilize metal and metal sulfide nanoclusters. We have attempted to synthesis silver nanoparticle-loaded zeolite Y by an ion exchange method followed by a biogenic reduction method using lemon juice as a reducing agent. The antimicrobial activity of the silver ion, silver nanoparticles and silver chloride-modified zeolite was investigated against various Gram negative and Gram positive microorganisms. The silver nanoparticle-loaded zeolite was further functionalized with amoxicillin antibiotic which exhibited a strong antimicrobial action to kill drug resistant microorganisms. The catalytic behavior of silver nanoparticles was investigated to reduce 4-Nitrophenol in presence of NaBH4. The catalytic reaction is found to be pseudo-first order, resulting in a rate constant that was comparable with previously-reported results.

Aniline oligomers are considered as one of the electron transfer mediators for the electrochemical oxidation of ascorbic acid. The electrochemical oxidation of ascorbic acid was investigated using aniline oligomer-functionalized polymer modified electrode. In the present investigation, we demonstrated a novel methodology for the in-situ modification of aniline oligomer onto the layered graphene sheet by using diazonium salt form as precursor molecule. An enhanced electrocatalytic current was obtained for the oxidation of ascorbic acid using aniline pentamer-functionalized reduced graphene oxide (AP-rGO). Detailed studies have been carried out to study the surface modified rGO by FTIR spectroscopy. A linear relationship between peak current against the concentration of ascorbic acid was observed within the ranges from 1 µM to 10 µM. The detection limit was measured at signal/noise (S/N) of 3. The present method can be utilized for the electrochemical detection of ascorbic acid present in food products like fruit juices.