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In this paper, we report our attempt to elaborate on cellulose-based materials and their potential application in membrane science, especially in separation applications. Furthermore, the cellulosic membrane has received attention for potential use as biomaterials such as novel wound-dressings and hemodialysis materials. In this mini-review, we mainly focus on the separation and antimicrobial properties of cellulosic membranes and the advanced synthesis/processing methods for superior functional quality for various potential applications. Finally, we conclude with the market and the impact of developments of future expectations.

A cost-effective, facile hydrothermal approach was made for the synthesis of SnO2/graphene (Gr) nano-composites. XRD diffraction spectra clearly confirmed the presence of tetragonal crystal system of SnO2 which was maintaining its structure in both pure and composite materials' matrix. The stretching and bending vibrations of the functional groups were analyzed using FTIR analysis. FESEM images illustrated the surface morphology and the texture of the synthesized sample. HRTEM images confirmed the deposition of SnO2 nanoparticles over the surface of graphene nano-sheets. Raman Spectroscopic analysis was carried out to confirm the in-plane blending of SnO2 and graphene inside the composite matrix. The photocatalytic performance of the synthesized sample under UV irradiation using methylene blue dye was observed. Incorporation of grapheme into the SnO2 sample had increased the photocatalytic activity compared with the pure SnO2 sample. The electrochemical property of the synthesized sample was evaluated.

In this study, activated carbon (ACs) adsorbent was synthesized using the lignocellulosic waste (LCB) seed from Adansonia digitata L. (BSP) using two steps of hydrothermal carbonization (HTC) followed by activation. The hydrothermally produced char of BSP was activated to produce porous activated carbon BSPAC, where K2CO3 was used as a chemical activating agent. Box Behnken Design was used to optimize the input variables of pyrolysis temperature (A1), residence time (B1), and ratio (C1) for the pyrolysis process. Removal percentage (β1), percentage carbon yield (β2), and fixed carbon (β3) percentage were chosen as output responses. The analysis of variance was utilized to generate appropriate mathematical models with subsequent statistical analysis. Physiochemical characterizations were carried out for the hydrothermally carbonized sample (BSPC) and the optimized activated sample (BSPAC). Langmuir, Freundlich, and Temkin models were employed to estimate the isotherm model parameters. The results demonstrated that HTC with subsequent mild activation using K2CO3 can be considered as a greener route to obtain better-quality porous carbon having surface area of 599 m2/gm for removal of Cu(II) cations from wastewater.

In this research, activated carbon (AC) was synthesized from ligno-cellulosic residues of Adansonia kilima (Baobab) wood chips (AKTW) using two-step semi-carbonization and subsequent pyrolysis using microwave-induced heating (MWP) in the presence of a mild activating agent of K2CO3. The influence of process input variables of microwave power (x1), residence time (y1), and amount of K2CO3 (z1) were analysed to yield superior quality carbon having maximum removal efficiencies (R1) for lead (II) cations from waste effluents, fixed carbon percentages (R2), and carbon yield percentages (R3). Analysis of variance (ANOVA) was used to develop relevant mathematical models, with an appropriate statistical assessment of errors. Level factorial response surface methodology (RSM) relying on the Box–Behnken design (BBD) was implemented for the experimental design. The surface area and porous texture of the samples were determined using Brunauer, Emmett, and Teller (BET) adsorption/desorption curves based on the N2 isotherm. Surface morphological structure was observed using field emission scanning electron microscopic (FESEM) analysis. Thermogravimetric analysis (TGA) was carried out to observe the thermal stability of the sample. Change in the carbon content of the samples was determined using ultimate analysis. X-ray diffraction (XRD) analysis was performed to observe the crystalline and amorphous texture of the samples. The retention of a higher proportion of fixed carbon (80.01%) ensures that the synthesized adsorbent (AKTWAC) will have a greater adsorption capacity while avoiding unwanted catalytic activity for our synthesized final sample.

In the current study, the ratio of a precise heat transfer growth to the different wt.% of the Zinc oxide-DW (ZnO-DW) based nanofluids are considered in a closed single-tube circular heat exchanger experimentally and by using ANSYS modeling. Four varying concentrations, 0.1%, 0.075%, 0.05%, and 0.025% wt. of the ZnO-DW nanofluids were considered and their thermal and hydrodynamic characteristics were determined experimentally and numerically. The experiments were conducted with base fluid (distilled water) as a working fluid for the validation of the 2-D numerical model. Using ANSYS-Fluent, a 2-dimensional domain was constructed and k-ϵ turbulent model was utilized to evaluate the continuity, energy, and momentum equations. All the nanofluids were experimentally and numerically examined with Reynolds (Re) numbers ranging from 5849 to 24544 and then validated using empirical correlations. Reynolds (Re) number, heat transfer coefficient, and Nusselt number were calculated and analyzed. The highest pressure drop was noticed for 0.1 wt% which is about 11184.9 m.Pas, while the highest friction (f) was 0.072983. Similarly, the maximum average heat transfer coefficient (h) and average Nusslet numbers (Nu) were been calculated both numerically and experimentally. At the highest 0.1 wt%. concentration of the ZnO-DW based nanofluids the supreme heat transfer was recorded about 13799.50 W/m2.K (71%) and the average Nusselt numbers (Nu) were noticed 176.47 (67.3%). Both experimental and ANSYS modeling results reflected that the 0.1% ZnO-DW based nanofluids contributed the highest heat transfer coefficient with an overall average deviation up to ±9.2%. Both experimental and numerical results showed promising and similar outcomes.

Nowadays, research interest is speedily growing for fabrication of semiconductor metal sulfide nanoparticles. Proper optimization of process variables for the synthesis process can ensure tunable morphologies and distinct characteristics. Appropriate synthesis strategy can alter their electrical, optical and catalytic properties significantly. A simple, one step, the hydrothermal approach has been undertaken to prepare CdS/rGO nanocomposite here. This technique ensures fabrication of graphene-based nanocomposites with outstanding electro-catalytic characteristics using a facile route. The structural, morphological and the electrochemical properties of the synthesized sample were observed. Surface morphological features together with its phase was identified using FESEM, TEM, and XRD analysis. The crystalline phase of the synthesized sample was confirmed from the X-ray diffraction pattern. Surface functional groups of the synthesized sample were analyzed using the FTIR and FT-Raman analysis. The optical characterization of the CdS and CdS/rGO nanocomposite were examined. The FESEM and TEM images were used to illustrate the surface morphology and particle size of the CdS and CdS/rGO nanocomposite. The elemental composition of the synthesized sample was evaluated using EDAX analysis. In this research, the values for dielectric loss, dielectric constant, and resistivity and AC conductivity of the synthesized samples were determined. Thus, the overall electrochemical features of the prepared sample were evaluated. The results elucidated here showed that the synthesized sample can be used as potential electrode materials for supercapacitor ensuring high energy. Keywords: Graphene, CdS/rGO, Nanocomposite, Electrochemical studies

Functionalized magnetite nanoparticles (Fe3O4) were prepared using the coprecipitation method followed by functionalization with a multipotent antioxidant (MPAO). The MPAO was synthesized and analyzed using FTIR and NMR techniques. In this study, the functionalized nanoparticles (IONP@AO) were produced and evaluated using the FTIR, XRD, Raman, HRTEM, FESEM, VSM, and EDX techniques. The average determined particle size of IONP@AO was 10 nanometers. In addition, it demonstrated superparamagnetic properties. The magnitude of saturation magnetization value attained was 45 emu g−1. Virtual screenings of the MPAO’s potential bioactivities and safety profile were performed using PASS analysis and ADMET studies before the synthesis step. For the DPPH test, IONP@AO was found to have a four-fold greater ability to scavenge free radicals than unfunctional IONP. The antimicrobial properties of IONP@AO were also demonstrated against a variety of bacteria and fungi. The interaction of developed nanoantioxiants with biomolecules makes it a broad-spectrum candidate in biomedicine and nanomedicine.

Abstract In this research, a facile co-precipitation method was used to synthesize pure and Mg-doped ZnO nanoparticles (NPs). The structure, morphology, chemical composition, and optical and antibacterial activity of the synthesized nanoparticles (NPs) were studied with respect to pure and Mg-doped ZnO concentrations (0–7.5 molar (M) %). X-ray diffraction pattern confirmed the presence of crystalline, hexagonal wurtzite phase of ZnO. Scanning electron microscope (SEM) images revealed that pure and Mg-doped ZnO NPs were in the nanoscale regime with hexagonal crystalline morphology around 30–110 nm. Optical characterization of the sample revealed that the band gap energy (E g) decreased from 3.36 to 3.04 eV with an increase in Mg2+ doping concentration. Optical absorption spectrum of ZnO redshifted as the Mg concentration varied from 2.5 to 7.5 M. Photoluminescence (PL) spectra showed UV emission peak around 400 nm. Enhanced visible emission between 430 and 600 nm with Mg2+ doping indicated the defect density in ZnO by occupying Zn2+ vacancies with Mg2+ ions. Photocatalytic studies revealed that 7.5% Mg-doped ZnO NPs exhibited maximum degradation (78%) for Rhodamine B (RhB) dye under UV-Vis irradiation. Antibacterial studies were conducted using Gram-positive and Gram-negative bacteria. The results demonstrated that doping with Mg ions inside the ZnO matrix had enhanced the antibacterial activity against all types of bacteria and its performance was improved with successive increment in Mg ion concentration inside ZnO NPs.

In this research, a one step, facile route has been undertaken to synthesise copper oxide/reduced graphene oxide (CuO/rGO) nanocomposites. X-ray powder diffraction analysis (XRD) was carried out to identity the crystalline structure and phase of the synthesised sample. Elemental analysis and surface morphological features were analysed using EDX and FESEM Images. Particle size as well as the shape of the as prepared composite was observed from HR-TEM images. Raman spectra illustrated the peak of the individual composite materials. The electrochemical properties of the prepared nanocomposite were investigated. The dielectric behaviour of the sample including dielectric constant, dielectric loss and AC conductivity was measured at various frequency levels. Temperature was varied accordingly to observe the effect of temperature on the dielectric properties of the sample.

In this research, Zinc Oxide-Ethylene @ glycol distilled water based nanofluid was synthesized using the sonochemical method. The convective heat transfer properties of as synthesized nanofluid were observed for a closed single circular tube pipe in turbulent flow regimes. The prepared nanofluids were characterized by ultra violet spectroscopy (UV–VIS), UV–VIS absorbance, X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Transmission electron microscopy (TEM) and stability analysis. Five calibrated k-type thermocouples were mounted on the surface of the test section. Analytical data related to heat transfer properties of the synthesized nanofluid for the heat exchanger, incorporated with the closed circular tube test section were collected. The addition of ZnO solid nanoparticles in the EG@DW mixture enhanced the value of thermal conductivity and other thermophysical characteristics of the nanofluids. Maximum thermal conductivity was observed at 45 °C for using 0.1 wt.% of ZnO nanoparticles EG@DW nanofluid. Increasing the wt.% of ZnO solid nanoparticles in the EG@DW mixture had increased the thermal conductivity subsequently with change in temperature from 20 to 45 °C. Furthermore, Nusselt numbers of ZnO-EG@DW-based nanofluid was estimated for the various concentration of ZnO present in EG@DW-based fluid. The presence of ZnO solid nanoparticles into the EG@DW base fluid escalate the Nusselt (Nu) number by 49.5%, 40.79%, 37% and 23.06% for 0.1, 0.075, 0.05 and 0.025 wt.% concentrations, respectively, at room temperature. Varying wt.% of ZnO (0.1, 0.075, 0.05 and 0.025) nanoparticles had shown improved heat transfer (h) properties compared to the base fluid alone. The absolute average heat transfer of ZnO-EG@DW nanofluid using the highest concentration of 0.1 wt.% was improved compared to the EG@DW mixture. The magnitude of absolute average heat transfer was increased from 600 W/m2k for the EG@DW mixture to 1200 W/m2k for ZnO-EG@DW nanofluid. Similarly, the heat transfer improvement for the other three wt.% (0.075, 0.05 and 0.025) was noticed as 600–1160, 600–950 and 600–900 W/m2k, respectively, which is greater than base fluid.