FESEM Analysis Research Articles

Kinetic Insights into Solar-Assisted Fabrication and Photocatalytic Performance of CoWO4/NCW Heterostructure

This work studies the kinetic model for the solar-driven fabrication of CoWO4/NCW heterostructure photocatalysts and investigates their enhanced photocatalytic degradation activity. The synthesis of CoWO4/NCW, its characterization, and the kinetic aspects of photocatalytic degradation under solar light. New nanocomposite prepared from Nano cellulose (NCW) by hydrolysis cotton waste (CW) by nitric acid and cobalt tungstate (CoWO4) prepared from sodium tungstate and cobalt chloride by wet chemical method and characterized through XRD, FTIR, EDX, and FE-SEM analyses. The composite's performance in organic oxidation from refinery wastewater (RWW) was evaluated under solar light. The high removal ratio was 97.4% for organic pollutants (OP) in refinery wastewater. The results indicate that the heterostructure exhibits improved photocatalytic performance compared to individual components, which kinetics model was the best to represent the photocatalytic degradation of organic pollutants from oily wastewater over the heterostructure CoWO4/NCW catalyst. Add future applications of this finding in the relevant industries. Copyright © 2024 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

A BIONIC-INSPIRED DRAGONFLY ALGORITHM FOR PARAMETRIC OPTIMIZATION AND DAMAGE INVESTIGATION DURING MACHINING OF MODIFIED POLYMER NANOCOMPOSITE

Polymer nanocomposite is commonly used to develop structural components of space, aircraft, biomedical, sensor, automobile, and battery sector applications. It remarkably substitutes the heavyweight metallic and nonmetallic engineering materials. The machining principles of polymer nanocomposites are intensely different and complex from traditional metals and alloys. The nonhomogeneity, abrasive, and anisotropic nature differs its machining aspect from conventional metallic materials. This investigation aims to execute the CNC drilling of modified nanocomposite using Graphene–carbon (G-C) @ epoxy matrix. The process constraints, namely, cutting speed (S), feed (F), and wt.% of graphene oxide (GO) vary up to three levels and are designed according to the response surface methodology (RSM) array. The nonlinear model is created to predict surface roughness (Ra) and delamination (Fd) on regression analysis. It has been found that the average error for Ra is 0.94% and for Fd it is 3.27%, which is acceptable in model predictions. The metaheuristics-based evolutionary Dragonfly algorithm (DA) evaluated the optimal parametric condition. The optimal setting prediction for the DA is observed as cutting speed (S)-37.68[Formula: see text]m/min, feed (F)-80[Formula: see text]mm/min, and wt.% of graphene oxide (GO)-1%. This algorithm demonstrates a higher application potential than the previous efforts in controlling Ra and Fd values. Both the drilling response values are found to be minimized when the cutting speed increases and the feed decreases. The best fitness value for the DA is 1.626 for surface roughness and 5.086 for delamination. This study agreed with the prediction model’s outcomes and the process parameters’ optimal condition. The defects generated during the sample drilling, such as fiber pull out, uncut/burr, and fiber breakage, were examined using FE-SEM analysis. The optimal findings of the DA module significantly controlled the damages during machining.

Fabrication and Characterization of Biocompatible Multilayered Elastomer Hybrid with Enhanced Water Permeation Resistance for Packaging of Implantable Biomedical Devices

This study presents the synthesis and characterization of hexadecyl-modified SiO2 (HD-SiO2) nanoparticles and their application in the fabrication of a multilayered elastomer hybrid sheet to enhance water resistance in implantable biomedical devices. The surface modification of SiO2 nanoparticles was confirmed via FT-IR and TGA analyses, showing the successful grafting of hydrophobic hexadecyl groups. FE-SEM and DLS analyses revealed spherical HD-SiO2 nanoparticles with an average size of 360 nm. A multilayered elastomer hybrid sheet, consisting of a PDMS-based circuit-protecting body, a water resistance layer of HD-SiO2, a planarization layer, and a biocompatible layer of polydopamine, was fabricated and characterized. The water resistance layer exhibited superhydrophobic properties, with a water contact angle of 154.7° and a 27% reduction in water vapor transmission rate (WVTR) compared to the circuit-protecting body alone. The device packaged with both the circuit-protecting body and water resistance layer demonstrated a tenfold increase in operational lifespan in water medium compared to the device without the water resistance layer. Cytotoxicity and cell proliferation tests on human dermal fibroblast cells (HDFn) confirmed the biocompatibility of the multilayered sheet, with no significant cytotoxicity observed over 48 h.

Harnessing Novel Reduced Graphene Oxide-Based Aerogel for Efficient Organic Contaminant and Heavy Metal Removal in Aqueous Environments

Ensuring clean water sources is pivotal for sustainable development and the well-being of communities worldwide. This study represents a pioneering effort in water purification, exploring an innovative approach utilizing modified reduced graphene oxide (rGO) aerogels. These advanced materials promise to revolutionize environmental remediation efforts, specifically removing organic contaminants from aqueous solutions. The study investigates the exceptional adsorption properties of rGO-aerogel, enhanced with cysteamine, to understand its efficacy in addressing water pollution challenges. The characterization methods utilized encompass various analytical techniques, including FE-SEM, BET, FTIR, TGA, DSC, XPS, NMR, and elemental analysis. These analyses provide valuable insights into the material’s structural modifications and surface chemistry. The research comprehensively explores the intricacies of adsorption kinetics, equilibrium, and isothermal study to unravel the underlying mechanisms governing contaminant removal. MO and Ni2+ exhibited adsorption of 542.6 and 150.6 mg g−1, respectively, at 25 °C. Ni2+ has unveiled the highest removal at pH 5, and MO has shown high removal in a wide pH range (pH 4–7). Both contaminants have shown fast adsorption kinetic performance on an rGO-aerogel surface. This study aims to identify the synergistic effect of cysteamine and rGO in aerogel formation to remove heavy metals and organic contaminants. These findings mark a significant stride in advancing sustainable water-treatment methods and pioneering in synthesizing innovative materials with versatile applications in environmental contexts, offering a potential solution to the global water pollution crisis.

Modification Of a Screen-Printed Carbon Electrode with Nanoporous Gold by Electrodeposition and Dealloying of a Gold-Copper Alloy

In this study, a three-dimensional structure of nanoporous gold (NPG) was made by selectively corroding copper (Cu) from gold-copper (Au-Cu) alloys using a two-step electrochemical method. Given its large surface area and interconnected porous network, nanoporous gold is a suitable material for the advancement of electrochemical sensors. The screen-printed carbon electrode (SPCE) modified with nanoporous gold (NPG/SPCE) was fabricated by electrodepositing a gold-copper alloy from gold ion (Au3+) and copper ion (Cu2+) solution via cyclic voltammetry (CV) by scanning from -0.3 V to -0.8 V for 80 cycles. The copper is then removed via a dealloying process in 3M HNO3 using the cyclic voltammogram (CV) method by scanning potential from 0 V to +1.0 V for 100 cycles at 100 mV/s. The morphology, elemental composition, and electrochemical active surface area (ECSA) of NPG/SPCE electrodes were characterized using FESEM, EDX, and CV analysis, respectively. The electrochemical performance of the NPG/SPCE was compared with bare SPCE in a 10 mM potassium ferrocyanide (K4FeCN6) solution using cyclic voltammetry. The morphological study using FESEM revealed that the NPG/SPCE had an average pore diameter of 53 nm. The quantification of elements using EDX shows that 84 % of the copper in the electrodeposited gold-copper alloy electrode was successfully removed by the dealloying process. The higher number of cycles during the dealloying process led to producing NPG with higher ECSA electrodes. The ECSA of NPG/SPCE is 12 times greater than that of bare or unmodified SPCE in an equivalent geometrical area. NPG/SPCE has a much better electron transfer surface than bare SPCE due to its high surface area and gold surface properties, making it a potential sensing material for biosensing applications.

Nano Hydroxyapatite (Nano-HA) Based on Pholas Orientalis Shells and Degradation Analysis

Millions of tons of seashells are produced every day as waste around the world. These underutilized seashells waste was executed as calcium precursor by researcher to synthesis the nano-hydroxyapatite (nano-HA). Nano-HA was successfully synthesised from Pholas Orientalis seashells waste via the chemical precipitation method. Different sintering temperatures were implemented to evaluate the physicochemical criteria of nano-HA. The obtained powders were examined by various physicochemical methods such as XRD, FTIR, FESEM, EDX and degradation analysis. The peaks in XRD and FTIR analysis the HA is successfully produced. The FESEM images on the other hand showing the HA particle in nano size range with rice-like structure. Meanwhile, a variation of Ca/P ratio can be observed in respect to sintering temperatures. The Ca/P ratio for HA-WS, HA-S500 and HA-S700 sample is 1.78, 2.03 and 1.57 respectively. Different sintering temperatures result in different crystallinity value which consequently affects its degradation profile.

MoS2 nanosheet assisted poly vinyl alcohol cross-linked with carboxylated acryl-amido-2-methyl-1-propanesulfonic acid in medium temperature proton exchange membrane fuel cell application

ABSTRACT Initially, the carboxylated-acryl amido propane sulfonic acid (C-AMPSA) was synthesized through the thiol-ene reaction using 2-acrylamido-2-methylpropane sulfonic acid and 3-mercapto propane sulfonic acid monomers. The C-AMPSA was cross-linked with polyvinyl alcohol to create a non-perfluorinated membranes were of these acid group-containing monomers. Using a cross-linking technique, a poly vinyl alcohol cross-linked C-AMPSA (PVA-C-AMPSA) polymer was prepared. Following that, the MoS2 nanosheets (NSs) were synthesized through the one-pot hydrothermal method, and their phase purity, functionality, and morphology were evaluated by p-XRD, FT-IR, and FE-SEM analyses. These nanosheets were then incorporated into PVA-C-AMPSA polymer nanocomposite membranes at various concentrations (0%, 1%, 2%, 3%, and 5% by weight). In addition, the physicochemical properties of bare and MoS2 nanosheets incorporated PVA-C-AMPSA polymer nanocomposite membranes were assessed, including water uptake, swelling ratio, and ion-exchange capacity. Remarkably, the membrane with 5% of MoS2 NSs in PVA-C-AMPSA displayed an ion-exchange capacity of 1.13 mmol g−1 and a proton conduction of 1.8 × 10−3 S cm−1 at 110°C. The Arrhenius plot indicated that the proton transport was involved in both Grotthuss and vehicular mechanisms. In the fuel cell testing, the PVA-C-AMPSA polymer nanocomposite membrane containing MoS2 NSs demonstrated superior performance, achieving a peak power density (PD) exceeding 0.7 W cm−2 and an open-circuit voltage (OCV) surpassing 0.93 V at 110°C. In contrast, the pure PVA-C-AMPSA membrane exhibited a peak PD of over 0.4 W cm−2 and an OCV of around 0.6 V at the same temperature. Additionally, the 5% of MoS2 NSs incorporated PVA-C-AMPSA polymer nanocomposite membrane exhibited outstanding oxidative stability with 87.7% of degradation when exhibited to a Fenton reagent at 80°C for 8 h.

Investigating the effect of Cu underlayer and FTO etching towards photoelectrochemical performance enhancement of Cu2O photoelectrode

Cuprous oxide (Cu2O) exhibits potential as a photoactive material for photoelectrochemical water splitting, owing to its appropriate bandgap, efficient charge carrier separation, and ability to enhance solar-driven hydrogen production. This study investigates the influence of substrate etching, Cu underlayer and Cu2O electrodeposition time, and annealing time on enhancing the photoelectrochemical (PEC) performance. Electrodeposition and thermal oxidation techniques were used to fabricate the Cu2O/Cu/FTOe-A photocathode. It has been observed that FTO etching improves adhesion, light transmission, and efficiency. A Cu underlayer also impacts the PEC performance, wherein an ideal thickness of Cu leads to enhanced PEC performance. This study also focuses on the annealing time that leads to CuO layers and nanowires forming on the Cu2O surface. The structural and chemical changes before and after annealing are confirmed via XRD, XPS, AFM and FESEM analyses. UV–Vis analysis also reveals that the presence of Cu underlayer, FTO etching, and the annealing process affect the electrical properties and light absorption capacities of the Cu2O photoelectrode. Electrochemical impedance analysis (EIS) and Mott-Schottky analysis have provided insights into the enhanced charge transfer properties and band bending in the Cu2O/Cu/FTOe-A, resulting in enhanced PEC performance. Overall, this study provides significant insights into the understanding and enhancement of Cu2O/Cu/FTOe-A photocathodes for potential use in PEC water splitting applications.

Enhanced photoelectrochemical CO2 reduction activity towards selective generation of alcohols over CuxO/SrTiO3 heterojunction photocathodes

Photoelectrochemical reduction (PECR) of CO2 to value-added chemicals and fuels will reduce the dependency on fossil fuels, also it will solve environmental issues that arise due to greenhouse gases. A heterojunction of CuxO/SrTiO3 with varying post-annealing temperature ranges from 300 to 600 °C (CS300-600) was synthesized by overlying the spin-coated SrTiO3 on electrodeposited Cu2O over the FTO glass substrate. The synthesized photoelectrode's crystallinity and phase formation significantly varied by varying the post-annealing temperature, which was characterized via XRD and Raman spectroscopy. Optical, morphological, type of heterojunction formation and elemental surface oxidation states of photoelectrodes were studied through UV–visible DRS spectrum, FE-SEM, and XPS analysis respectively. Electrocatalytic analysis such as Linear Sweep Voltammetry (LSV), and Electrochemical Impedance Spectrometry (EIS) was employed, thus it conforms to the highest photocurrent density (−1.38 mA/cm2 at −0.6V vs. Ag/AgCl), and low charge transfer resistance (RCT=0.412 kΩ) at the electrode-electrolyte interfaces for CS500 photoelectrode as compared to others photoelectrodes. PECR of CO2 to liquid product formation was evaluated by applying different potential ranges (0 to −0.6 V vs. Ag/AgCl). Highest methanol formation of 48.69 μmol.cm−2hr−1, which is approximately 9 times enhanced as compared to the pure Cu2O (5.62 μmol.cm−2hr−1) photoelectrode at 0 V vs Ag/AgCl for CS500 heterojunction. Optimization of overlaying SrTiO3 synthesis temperature for crystallization formation on Cu2O and applied photoelectrode potential findings could pave the way for designing other new heterojunction types for selective liquid alcohol production.

Green synthesis of self-oriented flower-like Ag@Ag2O nanostructures functionalized with L-Tryptophan for colorimetric simultaneous determination of ultra-trace level of thiamin and riboflavin

The study focuses on the green synthesis of Ag@Ag2O nanostructures using Padina algae extract and functionalizing them with L-tryptophan to enhance their properties as a colorimetric sensor for simultaneous detection of ultra-trace levels of thiamin and riboflavin. The nanostructures are characterized using techniques like XRD, FESEM, FTIR, TEM, AFM, and DLS to understand their morphology, structure, and interactions with target molecules. FESEM analysis revealed the hierarchical flower-like Ag@Ag2O nanostructures. The TEM image shows the formation of core-shell nanostructures. Also, DLS analysis and surface zeta potential spectra illustrated the aggregated nature of fabricated nanocomposites in the presence of vitamins. The study is the first to report simultaneous determination of thiamin and riboflavin using a colorimetric sensor based on Ag@Ag2O-L-Try nanocomposites using partial leas square (PLS). The dynamic range of thiamin and riboflavin was achieved in 0.1 mol L−1 acetate buffer pH 4 and the ratio Ag@Ag2O: L-try 1:1. The Ag@Ag2O-L-Try sensor exhibited two linear ranges of 0.1- 1.0 and 3-350 µMol L− 1 for riboflavin and a linear range 3.0–60 µMol L− 1 for thiamin. Also, low detection limit of 1.92 µMol L− 1 and 0.048 µMol L− 1 was obtained for riboflavin and thiamin, respectively. The results indicated that the success of the method depends on the selective and sensitive colorimetric assay of the sensor along with the simultaneous determination by the PLS algorithm. Hence, the proposed technique can be used for the accurate and precise determination of vitamins in different pharmaceutical syrup and tablet samples.

ZnFe(PBA)@Ti3C2Tx nanohybrid-based highly sensitive non-enzymatic electrochemical sensor for the detection of glucose in human sweat

The ZnFe prussian blue analogue [ZnFe(PBA)] was infused with Ti3C2Tx (MXene) denoted as ZnFe(PBA)@Ti3C2Tx and was prepared by an in-situ sonication method to use as a non-enzymatic screen printed electrode sensor. The advantage of non-enzymatic sensors is their excellent sensitivity, rapid detection, low cost and simple design. The synthesized ZnFe(PBA)@Ti3C2Tx was characterized for its physical and chemical characterization by XRD, Raman, XPS, EDAX, and FESEM analysis. It possessed multiple functionalized layers and a cubic structure in the nanohybrid. Further, the sensor was investigated by using electroanalytical studies such as cyclic voltammetry and chronoamperometry analysis. The enhanced surface area with a cubic structure of ZnFe(PBA) and the excellent electrical response of Ti3C2 nanosheet support the advancement of a non-enzymatic electrochemical glucose sensor with improved sensitivity of 973.42 µA mM−1 cm−2 with the limit of detection (LOD) of 3.036 µM (S/N = 3) and linear detection range (LDR) from 0.01 to 1 mM.

Novel tempo oxidized polyvinyl alcohol/ cellulose nanocrystal-based nanocomposite membrane for malachite green dye removal.

In this study, in-situ modification by TEMPO oxidation was performed after nanocomposite synthesis to improve its properties toward dye molecule removal. The unoxidized and oxidized polymeric-based nanocomposite was denoted as PNC6 and PNC6O respectively. The nanocomposites were characterized using FESEM, FTIR, contact angle, XRD and BET analysis. Measurements of swelling ratio and chemical stability were also performed to provide insight into the durability of the nanocomposites. The effects of changing variables included contact duration, pH of aqueous solution, initial pollutant concentration, and temperature were observed. The kinetic study showed that the experimental data is best fitted with pseudo-second-order kinetics (R2 = 0.988 and 0.997 respectively), whereas on observing isotherm data, in both unoxidized and oxidized nanocomposite it fits well with Langmuir isotherm (R2 = 0.951 and 0.993 respectively). In addition, the effects on Gibb's free energy, Enthalpy, and Entropy were measured in terms of thermodynamic characteristics, it was established that dye molecules adsorption mechanism is endothermic and spontaneous in behaviour. To check regeneration tendency of the nanocomposite seven consecutive adsorption desorption cycles were run and about 90% and 80%, regeneration ability could be seen in an unoxidized state (PNC6) and an oxidized state (PNC6O) respectively upto 5th cycle after that the tendency get reduced. This study suggests that this novel polymeric nanocomposite can be employed as an efficient and relatively inexpensive adsorbent for dye removal from aqueous solutions.

Enhanced adsorption of malachite green (MG) dye using RF glow oxygen plasma-modified coconut carbon shell: A sustainable approach for effluent treatment

The textile industry produces dye pollutants that are both harmful and difficult to degrade. This study explores the enhanced adsorption of Malachite Green (MG) dye using coconut carbon shells treated with RF glow oxygen plasma discharge. Plasma treatment improved the surface properties of the adsorbent by introducing oxygen-containing functional groups and increasing surface polarity, which boosted dye adsorption through hydrogen bonding, electrostatic interactions, and π-π stacking. Experimental results revealed that a 10-minute plasma treatment optimally enhanced adsorption capacity by 39 % compared to untreated samples. The Langmuir isotherm model demonstrated a maximum adsorption capacity (qm) of 161 mg/g, surpassing the Freundlich model. At pH 8, using 0.2 g of adsorbent in 50 mL solutions with initial dye concentrations of 25 mg/L and 100 mg/L, the 10-minute plasma-treated samples achieved adsorption capacities of 6.01 mg/g and 23.95 mg/g, respectively, compared to 4.72 mg/g and 17.2 mg/g for the untreated samples. This corresponded to removal efficiencies of 96.12 % and 95.8 % for the treated samples, and 75.6 % and 68.8 % for the untreated samples, after 80 min of contact at 200 rpm. UV–vis spectrophotometry confirmed the reduction in dye concentration after adsorption. FE-SEM analysis revealed that plasma treatment created micro-pores on the coconut carbon shell, enhancing adsorption capacity, while SEM-EDX analysis showed increased oxygen content after 10 min of treatment. FTIR analysis identified additional carbonyl (-C=O) and hydroxyl (-OH) groups, indicating the incorporation of oxygen-containing functional groups due to plasma treatment. Confocal Raman microscopy was also used to analyze the microstructural changes in the samples.

Improving thermoelectric performance of Nickel substituted ZnSb alloy through carrier engineering and nanostructuring

Zn1-xNixSb (0 ≤ x ≤ 0.08) nanostructures were prepared by the planetary Ball milling technique. XRD analysis confirms the phase purity and orthorhombic crystal structure of the samples. FESEM analysis shows the spherical morphology of the Zn1-xNixSb samples. The EDX and elemental mapping analysis confirms the composition and elemental distribution of Zn1-xNixSb (0 ≤ x ≤ 0.08) alloys. HRTEM images clearly show the interfaced grains with grain boundaries. DRS-UV analysis revealed the narrowing of bandgap while increasing the Ni content in Zn site due to alloying effect. The synthesized Zn1-xNixSb alloys show low resistivity compared to pure samples due to high carrier concentrations. Seebeck coefficient of Zn1-xNixSb alloys were measured from room temperature to 635 K. A high-power factor of 1344 µW/m K2 was obtained for the Zn0.98Ni0.02Sb sample at 533 K compared to pristine ZnSb (574 µW/m K2 at 533 K). High thermoelectric figure of merit (zT) of 0.69 was achieved for Zn0.98Ni0.02Sb sample at 533 K compared to pristine ZnSb (zT of 0.34 at 533 K). The experimental results illustrated that Nickel substitution is a one of the possible ways to improve the thermoelectric figure of merit of ZnSb alloys.

Self-powered γ-In2Se3/p-Si heterojunction for photodetection: exploring humidity and light intensity dependent photoresponse

In this study, high-quality γ-In2Se3 thin films were successfully deposited on p-Si substrates via the RF sputtering technique. Structural characterization using XRD and Raman spectroscopy confirmed the formation of the hexagonal γ-phase of In2Se3 film. FESEM analysis revealed the presence of small, homogeneous, and well-defined grains in the prepared γ-In2Se3 film. EDS analysis confirmed the stoichiometric composition (∼ 2:3) of the In2Se3 films. XPS further validated the presence of In, Se, and Si elements in the deposited films. Band gap analysis using UV-visible spectroscopy yielded a value of 1.96 eV for the γ-In2Se3 film. Integration of γ-In2Se3 with p-type Si enhanced photoresponsivity of 47.9 mA/W, photosensitivity of 282, and photo detectivity of 8.45 × 1010 Jones. The self-powered γ-In2Se3/p-Si heterojunction-based photodetector exhibited rapid rise time attributed to the type II band alignment structure, facilitating efficient electron-hole pair separation and minimizing recombination. Furthermore, humidity and light intensity-dependent photodetector properties of γ-In2Se3/p-Si heterojunction photodetector were also investigated. An increase in photocurrent from 271 to 291 µA was observed with rising humidity levels, indicating the device’s sensitivity to humidity variations. Furthermore, light intensity dependence studies revealed a linear relationship between photocurrent and incident light intensity, demonstrating the device’s reliable response across various illumination levels.

Reaction-assisted MOF manipulation for synthesis of UIO-66-NHCHO topology for prodrug fabrication: pH-responsive targeted drug delivery

A pH-responsive metal-organic framework (MOF)-based prodrug was synthesized via a premeditated formic acid-assisted amide reaction to form the UiO-66-NHCHO topology from UiO-66-NH2. This topology can be covalently attached to the methotrexate drug (MTX) to form theUiO-66-NH-HCN-MTX prodrug. The pristine MOF, UiO-66-NHCHO, and prodrug were characterized using PXRD, FT-IR, FE-SEM, BET, TGA, and NMR analyses. The solid-state NMR and FT-IR confirmed UiO-66-NHCHO topology.The loading efficiency and capacity of the prodrug were 88.96 % and 100.07 mg/g, respectively. These values were 12.90 % and 13.25 mg/g higher than those of the MTX-loaded MOF. This confirms the role of bonding in prodrug synthesis, beyond merely loading MTX through drug adsorption. At low pH the applied prodrug was activated due to CN cleavage. By decreasing pH from 7.4 to 5.5, imitating a tumor environment, the cumulative release of MTX increased by 64.94 %. This release rate was reached by 550 min, which was 230 min longer than the maximum MTX release from the loaded MOF. Such a premeditated delay can effectively suppress the burst release of MTX. At both pH levels, the Higuchi release kinetic model fit the release data better than other models, demonstrating that diffusion through the MOF pores controls drug delivery.

One-pot biocatalysis of potato rhamnogalacturonan and the role of its deacetylation in efficient inhibition of colon cancer cells and hydrogel mediated colon-targeted drug delivery

Deacetylation of potato rhamnogalacturonan (PRG) by rhamnogalacturonan acetyl esterase (CtPae12B) was explored for enhanced hydrolysis of PRG by rhamnogalacturonan lyase (CtRGLf) and the effects of deacetylated PRG were studied in enhancing inhibition of colon-cancer cells and formation of colon-targeting drug delivery material. Pre-treatment of PRG with CtPae12B resulted in increased relative activity of CtRGLf. CtPae12B removed acetyl groups from both O-2 and O-3 positions of D-galactopyranosyluronic acid residues of PRG, resulting in 98 % deacetylation. PRG displayed 21.9 % degree of acetylation and 7.7 % degree of methylation. TLC and ESI-MS analysis of CtRGLf hydrolysed PRG showed unsaturated RG di-saccharide as the smallest product, with m/z 322. Deacetylated PRG-oligosaccharides displayed higher, 50 % inhibition of colon-cancer HCT-116 cells (with shrunken and globular morphology) than 35 % inhibition by acetylated PRG-oligosaccharides. FESEM and BET analysis of CtPae12B-treated PRG showed porous structure and significantly higher total surface area and pore volume than non-enzyme treated PRG. Higher drug entrapment efficiency and lower drug release rate of CtPae12B-treated PRG hydrogel (0.0033 min−1 at pH 1.2 and 0.009 min−1 at pH 7.4), than non-enzyme treated PRG hydrogel, (0.0057 min−1 at pH 1.2 and 0.02 min−1 at pH 7.4), showed it to be a potential biomaterial for sustainable colon-targeted drug delivery.

Designing of a proficient macro porous metallo-polymer of iron with anion functionality: A sustainable approach for arsenic remediation from water

In this study, a novel porous metallo-polymeric network named poly(Ferric trimethacrylate-co-4-Vinyl benzyl chloride), incorporating an iron moiety, was developed for arsenic remediation from water. The synthesis of crosslinked q(pFeVBC) was carried out via suspension polymerization and functionalizing it with hexamethylenetetramine, resulting in a porous three-dimensional structure. Characterization using FTIR, FESEM, XPS, XRD, and BET-SA analysis confirmed its properties. Various monomer ratios were tested to optimize q(pFeVBC) for arsenic removal. The q(pFeVBC) exhibited significant adsorption capacities (qe max exp) of 8.33 mg g−1 for As(V) and 7.9 mg g−1 for As (III), owe to its unique architecture (integrated iron moiety and anion functionality) and porous texture (SA: 112 m2 g−1, pore size: 1.27–2.07 µm), which is close to the capacity calculated by Langmuir model (qe max theo) 8.719 mg g−1 for As (V) and 8.463 mg g−1 for As (III). The PSO kinetic model showed excellent fitting for both arsenic forms. Thermodynamic studies indicated a spontaneous and endothermic adsorption process. Additionally, a 4:10:1 ANN model accurately predicted adsorption behavior.

Mechanical Properties and Tribological Study of Bottom Pouring Stir-Cast A356 Alloy Reinforced with Graphite Solid Lubricant Extracted from Corn Stover

The present work epitomises extracting the graphite (Gr) solid lubricant from the corn stover. The extracted Gr was incorporated as reinforcement in the A356 alloy (Al-7Si), and the effect of the Gr particles on the mechanical and tribological properties was investigated. In spite of this, the input process parameters for the dry sliding wear test at room temperature against the EN31 steel disc were optimised through ANOVA analysis. The fabricated A359—X wt% (X = 0, 2.5, 5, 7.5) composite through bottom pouring stir casting techniques was analysed microstructurally by using XRD and FESEM analysis. The micro Brinell hardness and tensile strength were investigated per ASTME10 and ASTME8M standards. A wear test was performed for the composite pins against the EN31 steel disc according to ASTM G99 specifications. The XRD analysis results depict the presence of carbon (C), aluminium (Al), and silicon (Si) in all the wt% of the Gr reinforcement. However, along with the elements, the Al2Mg peak was confirmed for the A356—7.5 wt% Gr composite and the corresponding cluster element was confirmed in FESEM analysis. The maximum micro Brinell hardness of 92 BHN and U.T.S of 123 MPa and % elongation of 7.11 was attained at 5 wt% Gr reinforcement due to uniform Gr dispersion in the A356 alloy. Based on the ANOVA analysis, the optimal process parameters were obtained at 20 N applied load, 1 m/s sliding velocity, and 1000 m sliding distance for the optimal wear rate of 0.0052386 g/km and 0.364 COF.

Tuning of Particle Size of Zeolitic Imidazolate Framework-7 via Rapid Synthesis Duration for CH4 Adsorption

In this work, zeolite imidazolate framework-7 (ZIF-7) nanoparticles are synthesized via a solvothermal method and rapid synthesis durations of 1 h and 3 h. The effect of the synthesis duration on the structural properties of ZIF-7 was characterized by XRD and FESEM analyses. Subsequently, CH4 single gas adsorption over ZIF-7 nanoparticles was examined using the volumetric method at room temperature and pressure ranging from 2 to 9 bar. The results showed that the synthesized ZIF-7 adsorbents were highly crystalline with a well-defined and homogeneous particle size distribution of 50–60 nm. It was found that increasing the synthesis duration from 1 h to 3 h did not amend the structure and morphology of the resultant samples significantly, mainly due to the short synthesis duration. Meanwhile, the CH4 adsorbed by ZIF-7 nanoparticles increased with rising pressure for both samples, and the ZIF-7 nanoparticles synthesized at 3 h showed a greater adsorption capacity than that of 1 h, mainly due to its higher crystallinity and well-developed pore structure. The ZIF-7 synthesized at 3 h demonstrated an adsorption capacity up to 2.2 mol/kg, which was higher than those values reported in the literature for micron-sized ZIF-7 samples. The CH4 gas adsorption behavior of ZIF-7 nanoparticles synthesized at 1 h and 3 h were well predicted by the Langmuir isotherm model, with coefficients of determination, R2, of 0.9994 and 0.9982, respectively.