Chemical Functional Groups Research Articles

Enhancing the degradation of microplastics through combined KMnO4 oxidation and UV radiation

The pervasive issue of microplastics in aquatic environments presents a formidable challenge to traditional water treatment methodologies, including those utilizing KMnO4. This study pioneers advanced oxidation processes (AOPs) method aimed at improving the degradation of PE microplastics by employing a dual treatment strategy that combines KMnO4 oxidation with UV irradiation. Detailed analysis of the surface modifications and chemical functional groups of the treated PE microplastics revealed the establishment of Mn-O-Mn linkages on their surfaces. Weight reductions of 3.9%, 4.9%, and 7.5% were observed for the KMnO4/UVA, KMnO4/UVB, and KMnO4/UVC treatments over seven days, respectively. The emergence of carboxyl and hydroxyl groups played a crucial role in accelerating the degradation process. Notably, the combined application of UVC rays and KMnO4 resulted in the most effective degradation of PE microplastics observed in our study. The process significantly enhanced the formation of MnO2 particles from KMnO4 oxidation, with concentrations ranging from 0.036 to 0.070 mM for KMnO4/UVA, 0.066–0.097 mM for KMnO4/UVB, and 0.086–0.180 mM for KMnO4/UVC. Furthermore, the influence of varying pH levels, KMnO4 concentrations, and different water sources on the degradation efficacy was investigated. The pivotal role of free radicals and reactive manganese species in promoting the degradation of PE microplastics was identified. A comparative evaluation with treatments solely utilizing KMnO4 or UV light highlighted the enhanced effectiveness of the combined approach, demonstrating its potential as an efficient solution for reducing microplastic contamination in aquatic systems.

Zein and 3-Aminophenyl Boronic Acid Conjugated Polyvinylpyrrolidone Polymer Blend: Electrospinning, Characterization, and Mucoadhesive Drug Delivery.

The era of mucoadhesive polymers has advanced to the next generation, focusing on targeted adhesion of chemical functional groups with mucosa. This work aims to develop boronic acid functionalized polymers, which could facilitate reversible binding with the mucin in the mucosa. Pendant groups of boronic acid were conjugated on the chains of polyvinylpyrrolidone (PVP) via C═N bonding. The evidence from FTIR spectroscopy, XPS analysis, and UV spectroscopy has been used for the confirmation of the chemical conjugation of 3-aminophenyl boronic acid (APBA) to PVP. Boronate ester formation is a pH-dependent process. High pKa values of APBA preferably cause the binding of trigonal-shaped boronic acid with sialic acid groups of mucin. Boronic acid moieties additionally benefited in mucoadhesion in comparison to PVP alone, which is a result of the formation of a five-membered boronate ester complex. The presence of boronic acid moieties enhanced the force of adhesion on porcine buccal mucosal tissue from 13.12 ± 1.52 to 19.04 ± 1.97 g force. Specific binding of the polymer to the mucosal surface caused prolonged adhesion of the polymer to the mucosal surface. A polymer blend of boronic acid functionalized PVP and zein has been explored for its potential for mucoadhesive delivery of propranolol hydrochloride.

Morphology and methanol permeability of sulfosuccinic acid cross‐linked polyvinyl alcohol and polyvinyl alcohol/Nafion nanofibrous membranes

AbstractCross‐linking of polyvinyl alcohol (PVA) and polyvinyl alcohol/Nafion (PVA/Nafion) electrospun nanofibers with sulfosuccinic acid (SSA) was investigated to assess their characterization and the effects of cross‐linking on the methanol permeability performance of the nanofibrous membranes. SSA was directly incorporated into the electrospinning polymer solution. The morphology, chemical functional groups, thermal stability, water stability and water swelling of the resulting nanofibers were examined. The effects of SSA concentration on ion exchange capacity (IEC) and methanol permeability of the nanofibrous membranes were discussed. Bead‐free and smooth nanofibers were produced for all SSA concentrations with a mean nanofiber diameter of 240–270 nm. It was shown that 15% SSA concentration was suitable for preserving the morphology of PVA nanofibers against water, while the morphology of PVA/Nafion nanofibers was preserved even without cross‐linking. The increase in SSA concentration led to increase in swelling in water. SSA cross‐linking was also shown to increase the thermal stability of the produced nanofibers. IEC increased by the increase in SSA concentration, while increase in SSA concentration led to a decrease in methanol permeability.

Silica-Biomacromolecule Interactions: Toward a Mechanistic Understanding of Silicification.

Silica-organic composites are receiving renewed attention for their versatility and environmentally benign compositions. Of particular interest is how macromolecules interact with aqueous silica to produce functional materials that confer remarkable physical properties to living organisms. This Review first examines silicification in organisms and the biomacromolecule properties proposed to modulate these reactions. We then highlight findings from silicification studies organized by major classes of biomacromolecules. Most investigations are qualitative, using disparate experimental and analytical methods and minimally characterized materials. Many findings are contradictory and, altogether, demonstrate that a consistent picture of biomacromolecule-Si interactions has not emerged. However, the collective evidence shows that functional groups, rather than molecular classes, are key to understanding macromolecule controls on mineralization. With recent advances in biopolymer chemistry, there are new opportunities for hypothesis-based studies that use quantitative experimental methods to decipher how macromolecule functional group chemistry and configuration influence thermodynamic and kinetic barriers to silicification. Harnessing the principles of silica-macromolecule interactions holds promise for biocomposites with specialized applications from biomedical and clean energy industries to other material-dependent industries.

Flexible and innovative PVA/ZrO2/g-C3N4/CNT nanocomposites film for optoelectronic applications

This study successfully prepared polyvinyl alcohol (PVA) polymer films doped with ZrO2/(g-C3N4/CNT) nanofillers using the solution casting technique. The crystal structure of the nanocomposite films was characterized by X-ray diffraction (XRD), revealing the semi-crystalline nature of PVA and an average ZrO2 crystallite size of 13.17 nm. Fourier-transform infrared (FTIR) spectroscopy confirmed the chemical composition and functional groups present in the nanocomposites. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis showed uniform dispersion of the nanofillers without noticeable phase separation, with EDX confirming the successful incorporation of ZrO2, g-C3N4, and CNT into the PVA matrix. X-ray photoelectron spectroscopy (XPS) further validated the elemental composition and chemical states, indicating the presence of carbon, oxygen, nitrogen, and zirconium. Optical analysis demonstrated that increasing ZrO2/(g-C3N4/CNT) content reduced the direct and indirect band gaps from 5.41 eV to 5.25 eV and from 5.18 eV to 4.92 eV, respectively. In addition, the single-oscillator energy (E0) and dispersion energy (Ed) increased, while the static refractive index (n0) decreased. Improvements were also observed in linear optical susceptibility (χ(1)) and third-order nonlinear optical susceptibility (χ(3)), enhancing the polarizability of the polymer molecules. These results indicate that PVA films doped with ZrO2/(g-C3N4/CNT) hold promise for optoelectronic applications due to their enhanced optical properties.

Electrospun biomass carbon-based porous nanofibers modified by green-dry cold plasma for gaseous formaldehyde adsorption

Biomass carbon-based porous nanofibers (BCNFs) derived from cellulose and chitosan were fabricated by combining electrospinning, carbonization, with cold plasma technologies for highly efficient adsorption of gaseous formaldehyde (HCHO). The effects of different carbonization temperatures and plasma atmospheres on the micro-morphology, porosity, surface hydrophilicity, graphitization degree, element contents, and chemical functional groups of BCNFs were investigated. The adsorption performance and the interaction between HCHO and of BCNFs were elucidated by theoretical calculation. The carbonized nanofibers at 800°C exhibited the highest specific surface area (584.974 m2 g−1). The surface wettability of BCNFs after plasma modification significantly changed from hydrophobicity to hydrophilicity corresponding to the static water contact angle varying from 117.07° to 0°. The optimal adsorption capacity of HCHO reached to 118.67 mg g−1 corresponding to the BCNFs modified in oxygen atmosphere at 500 W for 2 min, which was 70.23 % higher compared to the control. The maximum theoretical adsorption capacity can be achieved to 202.37 mg g−1 fitted by Freundlich model. The enhanced adsorption behavior of HCHO molecules by BCNFs with incorporating various oxygen (O) and nitrogen (N) containing functional groups by cold plasma was superior within the basal plane than at the edge. The adsorption energies of HCHO by the different types of O, N-containing functional groups were ranked as: carboxyl (-12.45 kcal mol−1) > hydroxyl (-12.27 kcal mol−1) > pyrrole (-10.25 kcal mol−1) > pyridine (-5.24 kcal mol−1). The enhanced adsorption mechanism was attributed to a strong combination of electrostatic interactions and van der Waals forces induced by various functional groups.

Characterization of food color additives and evaluation of their acute toxicity in Wistar albino rats

Background and Aim: The use of food dyes can cause certain diseases, such as anemia and indigestion, along with other disorders, tumors, and even cancer. Therefore, this study aimed to determine the chemical nature and toxicity of some commercial dyes locally used in processed foods compared with standard food dyes. Materials and Methods: Three types of standard and commercial food color additives (Sunset Yellow, Tartrazine, and Carmoisine) were extensively examined. The chemical structures and functional groups of the dyes were evaluated by Fourier-transform infrared (FTIR) spectroscopy. The melting temperatures of the dyes were also determined by chemical thermal analysis. The acute toxicity test to evaluate the standard and commercial food color safety was estimated by a range-finding study using 150 Wistar albino rats. Sub-groups were administered one of the three colors under study at doses of 2, 3, 4, and 5 g/kg body weight (BW) orally for 7 days. When no mortality was observed, an additional 15 g/kg BW was administered. Concerning the median lethal dose 50 (LD50), 38 rats were exploited using the up-and-down method. Results: Commercial dyes had lower melting points than standard colors. Regarding the range-finding study, rats receiving different doses of the dyes exhibited no signs of toxicity, no deaths, and no clinical or gross pathological signs throughout the 7 days of the experiment. However, the animals that were dosed with 15 g/kg BW of each dye showed signs of loss of appetite, tachycardia, drowsiness, and eventual death. The LD50 values of the commercial food dyes, particularly Sunset Yellow and Carmoisine, were lower than those of the standard dyes. Conclusion: Commercial food colors were more toxic to rats than standard food colors. Differences were observed between the purity of the standard and commercial dyes, and the latter ones contained different percentages of salt, indicating the occurrence of fraud in commercial markets. Keywords: acute toxicity, food colors, Fourier-transform infrared spectroscopy, lethal dose 50, range-finding study.

Cellulose, cellulose nanofibers, and cellulose acetate from Butia fruits (Butia odorata): Chemical, morphological, structural, and thermal properties

Cellulose possesses numerous advantageous properties and is a precursor to compounds and derivatives. The objective of this study was to isolate and characterize cellulose from Butia fruits and simultaneously produce cellulose nanofibers and cellulose acetate from the isolated cellulose. Cellulose extraction was performed using a combination of alkaline and bleaching treatments, while the production of cellulose nanofibers and cellulose acetate was achieved through acid hydrolysis and acetylation, respectively. The materials were characterized by their chemical composition, size distribution, zeta potential, morphology, relative crystallinity (XRD), functional groups (FTIR), molecular structure (NMR), and thermal stability (TGA). The Butia crude fibers presented 49.4 % cellulose, 4.5 % hemicellulose, 25.4 % lignin, and 1.3 % ash. The cellulose nanofibers presented an average diameter ranging from 13.7 to 93.1 nm and exhibited a high degree of crystallinity (63.3 %). FTIR, XRD, 13C, and 1H NMR analyses confirmed that the isolation processes effectively removed amorphous regions from the cellulose nanofibers and confirmed the cellulose acetylation process. As demonstrated, cellulosic materials derived from Butia fruit exhibit promise for various applications, including their potential use as reinforcing agents in polymer matrices, due to their high extraction yield, thermal properties, and crystallinity.

Effects of hexagonal boron nitride nanosheets on the biostabilization of recycled sands for geotechnical fill applications

Biostabilization techniques including plant enzyme induced calcite precipitation (EICP) and microbially induced calcite precipitation (MICP) represent promising and environmentally friendly methods for improving the engineering properties of recycled geomaterials for geotechnical fill applications. In this study, hexagonal boron nitride (h-BN) nanosheets were dispersed and utilized as nano-additives in the EICP and MICP reaction processes to facilitate the precipitation of calcium carbonate polymorphs (CaCO3) in washed recycled sands (RS) derived from construction and demolition (C&D) wastes for geotechnical fill applications. The investigation comprised a systematic range of biological and chemical microscopic and macroscopic experiments intending to stabilize the RS for geotechnical fill applications. The study results suggested that using h-BN nanosheets did not have a notable impact on bacterial growth or the functioning of bacterial and plant enzyme activity. In addition, it was observed that the optimal addition of h-BN nanosheet additives substantially increased CaCO3 precipitation by up to 34 % and 28 % in the EICP and MICP reaction processes respectively, which can be postulated to be due to the nanosheets acting as nucleation sites throughout the high surface area and negatively surface charge. Furthermore, the introduction of h-BN nanosheets led to a significant enhancement in the performance of unconfined compressive strength (UCS) of the stabilized RS through nanofillers and reinforcements, with improvements of up to 20 % and 13 % in the biostabilization of RS using the EICP and MICP after 10 treatment cycles. Detailed analyses, including Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) imaging, revealed that h-BN nanosheets, with a substantial surface area and effective chemical functional groups, interconnected with the CaCO3 mineral surface. Overall, the study suggests that integrating effective additives can improve the utilization of EICP and MICP in geotechnical fill applications, namely in road embankments and pavements, whilst providing both commercial viability and enhanced performance.

Synthesis and Characterization of Ester Derivatives of N-Phenylanthranilic Acid

N-Phenylanthranilic acid (fenamic acid) serves as the fundamental structure for synthesizing several non-steroidal anti-inflammatory drugs, antibacterial drugs and also functions as a modulator of membrane transport. To reduce the dose-related side effects of existing drugs, research is focussing to improve fenamic acid derivative solubility and bioavailability. A series of ester derivatives of N-phenylanthranilic acid (MB-1 to MB-5) viz. 2-(phenyl amino)methyl benzoate, 2-(phenyl amino)ethyl benzoate, 2-(phenyl amino)isopropyl benzoate,2-(phenyl amino)butyl benzoate and 2-(phenyl amino)phenyl benzoate were synthesized. The chemical structures and functional groups of these derivatives were confirmed using elemental analysis and spectral data. Furthermore, the derived compounds were evaluated for their antibacterial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) strains using the agar-well diffusion method followed by molecular docking studies to predict binding interactions of the synthesized compounds with DNA gyrase.

Advancement in Soft Hydrogel Grippers: Comprehensive Insights into Materials, Fabrication Strategies, Grasping Mechanism, and Applications.

Soft hydrogel grippers have attracted considerable attention due to their flexible/elastic bodies, stimuli-responsive grasping and releasing capacity, and novel applications in specific task fields. To create soft hydrogel grippers with robust grasping of various types of objects, high load capability, fast grab response, and long-time service life, researchers delve deeper into hydrogel materials, fabrication strategies, and underlying actuation mechanisms. This article provides a systematic overview of hydrogel materials used in soft grippers, focusing on materials composition, chemical functional groups, and characteristics and the strategies for integrating these responsive hydrogel materials into soft grippers, including one-step polymerization, additive manufacturing, and structural modification are reviewed in detail. Moreover, ongoing research about actuating mechanisms (e.g., thermal/electrical/magnetic/chemical) and grasping applications of soft hydrogel grippers is summarized. Some remaining challenges and future perspectives in soft hydrogel grippers are also provided. This work highlights the recent advances of soft hydrogel grippers, which provides useful insights into the development of the new generation of functional soft hydrogel grippers.

Development of sustainable flame-retardant bio-based hydrogel composites from hemp/wool nonwovens with chitosan-banana sap hydrogel

Flame retardant (FR) finishing is crucial for developing protective textiles, traditionally relying on halogen, phosphorus, and phosphorus-nitrogen chemistries, which have limitations like toxicity and fabric stiffening. Innovative approaches such as nanotechnology, plasma treatments, and natural resource-based finishes are being explored to achieve sustainable FR textiles. This study presents the development and comprehensive characterization of hydrogel composites made from nonwoven fabrics composed of various hemp/wool blends (70/30, 80/20, and 90/10). The nonwoven fabrics were treated with a chitosan hydrogel incorporating banana sap to enhance their properties. Scanning electron microscope (SEM) examined the surface morphology and structural integrity of the composites, while Fourier transform infrared spectroscopy (FTIR) identified chemical interactions and functional groups. Differential scanning calorimeter (DSC) revealed thermal properties, water absorbency tests demonstrated hydrophilicity, mechanical testing assessed tensile strength, and vertical flammability tests evaluated fire resistance. SEM and FTIR revealed a successful coating of chitosan hydrogel with banana sap inclusions onto the hemp/wool nonwoven fabric, forming a composite structure. DSC analysis suggests higher chitosan content and hemp fiber ratio (like 70/30) lead to increased thermal stability of hydrogel composites. Higher chitosan concentrations in the hydrogel significantly improve the flame-retardant properties of hemp/wool nonwoven fabrics by reducing char length and enhancing protective char layer formation, with banana sap further promoting charring. These results indicate that the developed composite can be effectively used in flame-retardant textiles.

Evaluation of a New In Chemico Skin Corrosion Test

The purpose of this study is to evaluate a novel macromolecular test method for the identification of dermal corrosives. The simple in chemico test procedure involves allowing the material to be tested to interact with a skin biomarker for corrosivity and then adding a detection reagent. The corrosivity of the test substance is predicted based on the measured macromolecular damage, which results in reduced optical density of the detection reagent as compared with controls. This study aims to determine if such an extremely simple, cell-free test method can accurately identify dermal corrosives. To determine predictivity and repeatability, we tested 60 chemicals (30 in vivo dermal corrosives and 30 in vivo dermal noncorrosives; all tested in triplicate) representative of a broad range of chemical classes, functional groups, mixtures, and levels of toxicity. Validation results indicate the GHS multicategory and packing group assignment accuracy is on par with that of the Reconstructed Human Epidermis test method and the Membrane Barrier test method and for the global identification of corrosives, the method has a considerably higher accuracy (98 % vs. ∼80 %).

A Study on the Mechanisms of Coal Fly Ash to Improve the CO2 Capture Efficiency of Calcium-Based Adsorbents

Utilizing calcium-based adsorbents for CO2 adsorption through cyclic calcination/carbonization is one of the most cost-effective methods for carbon emission reduction. In order to improve the cycle stability of the adsorbents and the capture efficiency of CO2, this study used industrial solid waste coal fly ash for the hydration treatment of calcium-based adsorbent to explore the variations in the cyclic adsorption performance of the adsorbent under different doping ratios and hydration conditions. By means of various characterization techniques, the microscopic mechanism for improving the performance of the modified adsorbent was analyzed from the perspectives of chemical composition, physical structure, and surface functional groups of the adsorbents. The results demonstrated that the modification of coal fly ash could significantly enhance the carbonation performance and cycle stability of the adsorbent in multiple CO2 capture processes. The modified material doped with 5% coal fly ash had the highest total CO2 adsorption capacity, which increased by 13.7% compared to before modification. Additionally, the modified material doped with 10% coal fly ash exhibited the strongest cyclic adsorption capacity, which was 14.0% higher than that before modification, and the adsorption attenuation rate decreased by 32.2%. The characterization results showed that the reaction between calcium oxide and coal fly ash formed CaSiO3 and Ca12Al14O33 during the modification process, which was the primary reason for the improvement in the CO2 capture performance of the modified materials. This study provided a new perspective on the resource utilization of solid waste fly ash and efficient CO2 capture.

Photochemical Defluorinative Alkenylation of Trifluoromethyl Alkenes with Organoboronic Acids

We have developed a photo‐catalyzed defluorinative two‐component coupling reaction of trifluoromethyl alkenes and organoboronic acids, providing a straightforward and efficient route for the synthesis of functionalized gem‐difluorinated 1,4‐dienes. Both the chemical yields and functional group tolerance are generally good.

Effects of antioxidants on chemical and rheological properties of asphalt binders from different crude oil sources

Antioxidants can effectively mitigate or delay the oxidative aging degradation of asphalt binder, thereby improving pavement durability. While research has largely concentrated on the application of antioxidants to asphalt binders from a single source, limited studies have explored their effects on binders derived from different crude oil sources. Moreover, the relationship between the chemical and rheological properties of antioxidant-modified asphalt binders remains insufficiently understood. In this study, three antioxidants - zinc diethyldithiocarbamate (ZDC), Irganox 1010 and kraft lignin - were utilized and blended with base binders sourced from three distinct regions globally. Fourier transform infrared spectroscopy (FTIR) was utilized to analyze the impact of these antioxidants on the chemical composition of aged binders. Additionally, dynamic shear rheometer (DSR) and bending beam rheometer (BBR) tests were conducted to assess the high- and low-temperature performance of the antioxidant-modified binders, identifying the most effective antioxidant. The linear amplitude sweep (LAS) test further evaluated the performance of ZDC across binders from different crude oil sources. The results revealed three key findings: first, chemical functional group changes due to antioxidants are not always reflected in rheological performance; second, ZDC demonstrated superior performance across different base binders, as evidenced by improved aging indices, high-temperature rutting resistance, and enhanced fatigue and low-temperature cracking resistance; and third, asphalt binders from different crude oil sources exhibit varying sensitivities to antioxidant type and dosage. This study underscores the necessity of determining optimal antioxidant dosages for different asphalt binders, as the relationship between antioxidant dosage and effectiveness is not straightforward.

Assembling Zn2+ on surface of kevlar NanoFibers as functionalized separator for dendrite-free Zn anode and high-performance Zn metal batteries

The proliferation of wearable electronic products has made the development of flexible energy storage devices increasingly important. Among various options, aqueous Zn metal batteries are promising due to their low cost, safety, non-toxicity, environmental friendliness, and abundant element storage. However, the growth of dendrites on the anode surface of Zn metal batteries is a significant challenge to efficient transport of Zn2+, which leads to reduced battery capacity or even failure. This limitation hinders practical applications for these batteries. This study develops a functionalized separator with high ion transport performance and excellent mechanical performances by electrostatic assembling deprotonated PPTA− molecular chains with Zn2+ using Kevlar as a raw material. The successful assembly of Zn2+ is confirmed through chemical composition and functional group analysis. The prepared separator significantly shows the increased the transfer number of Zn2+ and decreased activation energy of Zn2+ deposition. The separator is used in Zn||Zn symmetric batteries, achieving a reversible deposition/stripping process of more than 180 h at a current density of 1 mA cm−2 and a deposition capacity of 1 mAh·cm−2. When applied to Zn||MnO2 batteries, an initial discharging specific capacity of up to 220 mAh·g−1 is obtained at a high current density of 2 A g−1, and the battery could be cycled stably for more than 1, 200 cycles, with a smooth and flat Zn anode surface and no obvious dendrite growth. The separator has good potential for flexible energy storage applications due to its excellent mechanical strength, which enables it to maintain high electrochemical activity even after bending 500 times at 180°. Overall, the functionalized separator effectively inhibits dendrite growth, improves the electrochemical stability of Zn metal batteries, and demonstrates significant application potential for other flexible energy storage applications.

Carbon Dots: A Versatile Platform for Cu2+ Detection, Anti-Counterfeiting, and Bioimaging.

Carbon dots (CDs) have garnered extensive interest in basic physical chemistry as well as in biomedical applications due to their low cost, good biocompatibility, and great aqueous solubility. However, the synthesis of multi-functional carbon dots has always been a challenge for researchers. Here, we synthesized novel CDs with a high quantum yield of 28.2% through the straightforward hydrothermal method using Diaminomaleonitrile and Boc-D-2, 3-diaminopropionic acid. The size, chemical functional group, and photophysical properties of the CDs were characterized by TEM, FTIR, XPS, UV, and fluorescence. It was demonstrated in this study that the prepared CDs have a high quantum yield, excellent photostability, and low cytotoxicity. Regarding the highly water-soluble property of CDs, they were proven to possess selective and sensitive behavior against Cu2+ ions (linear range = 0-9 μM and limit of detection = 1.34 μM). Moreover, the CDs were utilized in fluorescent ink in anti-counterfeiting measures. Because of their low cytotoxicity and good biocompatibility, the CDs were also successfully utilized in cell imaging. Therefore, the as-prepared CDs have great potential in fluorescence sensing, anti-counterfeiting, and bioimaging.

Fabrication of nanozeolite-Y/chitosan composite based on rice husks for efficient adsorption of methylene blue dye: kinetic and thermodynamic studies

In this work, three solid adsorbents were synthesized, namely, nanozeolite-Y prepared from rice husks ash by a sol-gel method as a green biosource (ZN), chitosan as a cationic biopolymer (CS), and nanozeolite-Y/chitosan composite (CSZ). An eco-friendly composite that consists of chitosan and nanozeolite-Y was used to combine the advantages of nanoparticles with biopolymers two materials to increase the removal % of methylene blue dye. All the synthetized solid adsorbents were investigated using TGA, nitrogen adsorption, SEM, TEM, FTIR, XRD, and zeta potential. The results showed that CSZ particles had a high specific surface area (432.3 m2/g), mesoporosity (with an average pore diameter of 2.59 nm), a smaller TEM particle size (between 28.6 and 60.7 nm), a lot of chemical functional groups, and high thermal stability. CSZ exhibited the maximum adsorption capacity (141.04 mg/g) towards methylene blue. The adsorption nature of methylene blue onto CS and CSZ is endothermic, spontaneous, and a physical adsorption process, while it is exothermic, nonspontaneous, physical adsorption process in the case of ZN, as confirmed by thermodynamic results. Pseudo-second order, Elovich, Dubinin-Radushkevich, Freundlich, Langmuir, Temkin, and adsorption models all fit the MB adsorption well, with correlation coefficients reaching about 0.9997. Nitric acid was found to be the best desorbing agent, with a desorption efficiency of about 99%.

Comparative studies on pinhole free CBD-CdZnS thin films on ITO and FTO substrate

The development of CdZnS thin films using the chemical bath deposition process in nonaqueous media is a technological challenge. In this work, 75 millilitres of ethylene glycol and ethanol (1:2 ratios) were used to develop a CdZnS thin film on ITO and FTO glass substrates using cadmium acetate, zinc sulphate, and thiourea. The ideal bath temperature was kept at 1300C and the anneal temperature of the film that had been deposited in the air was maintained at 3500C. The films have been examined using FTIR, WCA, FESEM, and XRD. XRD studies reveal that CdZnS films have a hexagonal crystal structure with a preference for orientation (002) during the deposition and annealing processes and the assessment of the various attributes have been done, such as dislocation density, micro strain, and grain size. FESEM study indicates that as deposited film on ITO glass have smooth surface and grains appear in the form of small needle shape of equal sizes where as FTO substrate reveals the grains of equal size throughout the entire surface in cluster form. It is also confirmed that both the CdZnS films formed on ITO and FTO substrates have hydrophilic quality. The presence of chemical bonds and functional groups was confirmed by FTIR analysis.