Microwave-Assisted Rapid Synthesis of Reduced Graphene Oxide-Based Gum Tragacanth Hydrogel Nanocomposite for Heavy Metal Ions Adsorption

Synthesis and characterization xanthan gum/acrylic acid/acrylamide modified with graphene oxide hydrogel nanocomposite for removal of methylene blue from aqueous solution

The demand for clean water has become a worldwide problem because of the pollutants' excessive and inappropriate use. In this regard, a new hydrogel nanocomposite adsorbent was fabricated from xanthan gum and graphene oxide via free radical polymerization for methylene blue (MB) dye removal. The physicochemical properties of the synthesized hydrogel nanocomposite were evaluated using scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The properties of the bare hydrogel and the adsorption of MB dye in an aqueous solution were enhanced by adding graphene oxide to the hydrogel matrix. The batch adsorption experiment revealed a maximum adsorption capacity of 1008 mg/g for the prepared hydrogel nanocomposite, using 250 mg/L of MB dye at pH 7 over the course of an hour. The findings of the adsorption kinetics model suggested that the order of the adsorption process of the prepared hydrogel nanocomposite is fitted well with pseudo-second-order kinetics. The regeneration study demonstrated excellent recyclability for the synthesized nanocomposite across five successive reusable cycles. The findings from the point of zero charge (pzc) and FTIR investigations indicate that electrostatic attraction is the primary force between the adsorbent and the dye molecules.

Natural gums-derived hydrogels for adsorptive removal of heavy metals: A review

This review explores advancing and refining hydrogels derived from natural gums for heavy metal ion adsorption, focusing on their efficiency, capacity, and influencing parameters. The high adsorption capacity of these hydrogels, with values reaching up to 384.6 mg/g (Pb2+) and 203.7 mg/g (Cu2+), is linked to functional moieties like -COOH and -OH, which bind to metal ions through electrostatic interactions, exchange of ions, and coordination mechanisms. Adsorption efficiency is governed by conditions such as duration of contact, temperature, and pH. Temperature studies imply that adsorption occurs through an endothermic mechanism, with positive ΔH values and negative ΔG values, validating the spontaneity and efficiency of the process. Adsorption isotherms, including Langmuir and Freundlich models, have shown promising fits, with a high correlation coefficient (r2 > 0.9). The kinetic study reveals that the adsorption follows pseudo-second-order kinetics, implying a chemisorption mechanism. The occurrence of interfering ions (e.g., Na+, Ca2+) can reduce adsorption efficiency, but their impact is minimal at lower concentrations. Overall, gum-based hydrogels provide an eco-conscious and reliable approach for metal ion removal in aqueous solutions, showing potential for large-scale environmental applications. Further studies focusing on improving adsorption capacity and scalability are recommended to enhance their practical utility in wastewater treatment.

Fabrication and Characterizations of Microwave‐Assisted Gelatin Cross‐Linked LBG/Guar Gum–Based Super Porous Hydrogels With Metformin Hydrochloride for Open Incision Wound Healing

The goal of this study was to fabricate gelatin cross‐linked Locust bean gum (LBG)/guar gum–based hydrogels with microwave assistance for diabetic wound healing applications and evaluate it for physicochemical properties. In the last few years, microwave irradiation has gained acceptance as a reliable technique for quickening and streamlining chemically modified reactions. In order to achieve this, metformin‐loaded LBG and guar gum–based hydrogel were formulated employing microwave radiation. Moreover, the microwave‐assisted–based metformin hydrogel are microwave‐assisted reaction sudden increase in temperature may led to distortion of molecules, very vigorous and which may be hazardous, but environmental sustainability and friendly chemistry concepts are supported by microwave irradiation. The optimized formulation (F3) showed significantly improved physicochemical properties, with a swelling capacity of 480.4% ± 2.5%. The results indicate an appropriate duration for adequate drugs diffusion and nutrition exchange. Controlled disintegrate and sustained release of embedded drug molecules from F3 may have an impact on antibacterial activity. The study indicated that microwave‐assisted polymer blend hydrogels had adequately improved physical qualities, making them a promising candidate for improving diabetic wound healing and hastening skin tissue regeneration.

Gum acacia based hydrogels and their composite for waste water treatment: A review

The non-toxic nature of natural polysaccharides and their biodegradability makes them the first choice of researchers. Various natural polysaccharides are available nowadays, like cellulose, starch, chitosan, gum acacia, guar gum etc. Among these, gum acacia is a common natural polysaccharide presently used in research and technology. It is highly biodegradable, pH stable and shows appropriate water solubility. It is used in research to synthesize hydrogels and hydrogel nanocomposites for various applications because of its antimicrobial, anti-inflammatory and excellent absorption properties. The major fields of applications include the stabilization of metal nanoparticles in the form of nanocomposites, wound dressing materials, delivery systems of various drugs and pharmaceutical agents, bioengineering, tissue engineering, purification of water, synthesis of antibacterial and antifungal composites for agricultural improvements, and many others. Due to the increasing problem of water pollution, the major focus is on research helping to reduce this problem. Gum acacia-based hydrogel and hydrogel composites were synthesized and tested for pollutant removal efficiency from wastewater by different researchers. The research on gum acacia hydrogel and their hydrogel composite applications for water purification, as well as their synthesis processes and properties, are summarized in this review article.

Advances in gum-based hydrogels and their environmental applications

Gum-based hydrogels (GBHs) have been widely employed in diverse water purification processes due to their environmental properties, and high absorption capacity. More desired properties of GBHs such as biodegradability, biocompatibility, material cost, simplicity of manufacture, and wide range of uses have converted them into promising materials in water treatment processes. In this review, we explored the application of GBHs to remove pollutants from contaminated waters. Water resources are constantly being contaminated by a variety of harmful effluents such as heavy metals, dyes, and other dangerous substances. A practical way to remove chemical waste from water as a vital component is surface adsorption. Currently, hydrogels, three-dimensional polymeric networks, are quite popular for adsorption. They have more extensive uses in several industries, including biomedicine, water purification, agriculture, sanitary products, and biosensors. This review will help the researcher to understand the research gaps and drawbacks in this field, which will lead to further developments in the future.

Tailoring Homogeneous Hydrogel Nanospheres by Facile Ultra-Sonication Assisted Cross-Linked Copolymerization for Rhodamine B Dye Adsorption

The present paper describes the design of shape-oriented hydrogel nanospheres using a facile ultrasonication-supported crosslinked copolymerization technique. The effect of variable monomer concentration on the homogeneity of hydrogel nanospheres was investigated. The chitosan-cl-poly(MMA) hydrogel nanospheres were well characterized using various techniques such as FTIR, XRD, TGA, SEM, and TEM. The chitosan-cl-poly(MMA) hydrogel nanospheres were studied for their swelling behavior and could potentially be used as a novel adsorbent for rhodamine B dye remediation from aqueous media. The study found that utilizing chitosan-cl-poly(MMA) nanohydrogel spheres at the optimal pH 5 increased RhB dye adsorption capacity from 7.9 to 17.8 mg/g (pH 2 to 5), followed by a slight reduction. Furthermore, when nanohydrogel concentration increased, adsorption capacity dropped from 18.03 to 2.8 mg/g, but adsorption percentage climbed from 90.2% to 97.8%. At an initial dye concentration of 140 mg/L, rhodamine B adsorption achieved 204.3 mg/g in 60 min. The rhodamine B dye adsorption study includes adsorption kinetics, isotherm, and thermodynamics analyses. The interpretation of the adsorption study revealed that Langmuir isotherms fit best with a qmax value of 276.26 mg/g, which is in close approximation with the experimental value, whereas pseudo-second-order kinetics explains the adsorption process rate. The interaction of RhB dye with chitosan-cl-poly(MMA) hydrogel nanospheres involves multiple forces such as electrostatic interactions, hydrogen bonding, van der Waals forces, etc.

Dynamics of reduced graphene oxide: synthesis and structural models

Technological advancements are leading to an upsurge in demand for functional materials that satisfy several of humankind's needs. In addition to this, the current global drive is to develop materials with high efficacy in intended applications whilst practising green chemistry principles to ensure sustainability. Carbon-based materials, such as reduced graphene oxide (RGO), in particular, can possibly meet this criterion because they can be derived from waste biomass (a renewable material), possibly synthesised at low temperatures without the use of hazardous chemicals, and are biodegradable (owing to their organic nature), among other characteristics. Additionally, RGO as a carbon-based material is gaining momentum in several applications due to its lightweight, nontoxicity, excellent flexibility, tuneable band gap (from reduction), higher electrical conductivity (relative to graphene oxide, GO), low cost (owing to the natural abundance of carbon), and potentially facile and scalable synthesis protocols. Despite these attributes, the possible structures of RGO are still numerous with notable critical variations and the synthesis procedures have been dynamic. Herein, we summarize the highlights from the historical breakthroughs in understanding the structure of RGO (from the perspective of GO) and the recent state-of-the-art synthesis protocols, covering the period from 2020 to 2023. These are key aspects in the realisation of the full potential of RGO materials through the tailoring of physicochemical properties and reproducibility. The reviewed work highlights the merits and prospects of the physicochemical properties of RGO toward achieving sustainable, environmentally friendly, low-cost, and high-performing materials at a large scale for use in functional devices/processes to pave the way for commercialisation. This can drive the sustainability and commercial viability aspects of RGO as a material.

Research Progress of Treatment Technology and Adsorption Materials for Removing Chromate in the Environment

Cr is used extensively in industry, so the number of Cr (VI) hazards is increasing. The effective control and removal of Cr (VI) from the environment are becoming an increasing research priority. In order to provide a more comprehensive description of the research progress of chromate adsorption materials, this paper summarizes the articles describing chromate adsorption in the past five years. It summarizes the adsorption principles, adsorbent types, and adsorption effects to provide methods and ideas to solve the chromate pollution problem further. After research, it is found that many adsorbents reduce adsorption when there is too much charge in the water. Besides, to ensure adsorption efficiency, there are problems with the formability of some materials, which impact recycling.

Electro-stimulated drug release by methacrylated hyaluronic acid-based conductive hydrogel with enhanced mechanical properties

Recently, the design of stimuli-responsive hydrogels for controlled drug delivery systems has been extensively investigated to meet therapeutic needs and optimize the release pattern of the drug. Being a natural polyelectrolyte, hyaluronic acid (HA) is excellent potential to generate new opportunities for electro-responsive drug carrier applications. In the current study, HA-based electroconductive hydrogel was developed as a novel smart drug carrier for anti-inflammatory drug release by the combination of in-situ and post polymerization mechanisms. HA was modified through methacrylation reaction to introduce photocrosslinkable groups into its structure and then reduced graphene oxide (rGO) was encapsulated into methacrylated HA (HA/MA) hydrogel by using the photopolymerization technique. In the post polymerization process, polyaniline (PANI) was incorporated/loaded into HA/MA-rGO polymeric network produced in previous step. The produced HA/MA-rGO-PANI hydrogel exhibited sufficient electrical conductivity providing the desirable electro-responsive ability for Ibuprofen (IBU) release. Furthermore, it has superior mechanical performance compared to pure (HA/MA) and rGO containing (HA/MA-rGO) hydrogels. IBU release from the hydrogel was successfully triggered by electrical stimulation and the cumulative drug release also enhanced by increasing of the applied voltage. These results highlighted that the novel HA/MA-rGO-PANI hydrogel could be a promising candidate for electrical-stimulated anti-inflammatory release systems in neural implant applications.

Carboxymethyl cellulose based sustainable hydrogel for colon-specific delivery of gentamicin

The current research includes the synthesis, improvement of NaCMC-cl-DMAA/AAc hydrogel and in-situ controlled release of gentamicin within various pH environments. The prepared hydrogel was then modified using boron nitride nanosheets aiming to enhancement in the adsorption rate. The prepared hydrogels were investigated by FTIR, XRD, FESEM, TGA/DSC, swelling and cell viability analysis. Cytotoxicity study indicated that prepared sample has a cytocompatibility nature towards healthy normal human cell line (FR2 cells). By changing the pH environment, the drug release properties of the hydrogels can be controlled. The cumulative rate of release for NaCMC-cl-DMAA/AAc hydrogel was 76.5 % at pH = 2.2 and 87.5 % at pH = 7.4. Whereas drug release rate for NaCMC-cl-DMAA/AAc-BNNSs hydrogel composite was 78.6 % at pH = 2.2 and 97.3 % at pH = 7.4 within 4320 min. Gentamicin release kinetics have been determined using the Korsemeyar-Peppas model, which confirms the drug release mechanism.

Polysaccharide-based biopolymer hydrogels for heavy metal detection and adsorption

BACKGROUND

With rapid development in agriculture and industry, water polluted with heavy metallic ions has come to be a serious problem. Adsorption-based methods are simple, efficient, and broadly used to eliminate heavy metals. Conventional adsorption materials have the problems of secondary environmental contamination. Hydrogels are considered effective adsorbents, and those prepared from biopolymers are biocompatible, biodegradable, non-toxic, safe to handle, and increasingly used to adsorb heavy metal ions.

AIM OF REVIEW

The natural origin and easy degradability of biopolymer hydrogels make them potential for development in environmental remediation. Its water absorption capacity enables it to efficiently adsorb various pollutants in the aqueous environment, and its internal pore channels increase the specific surface area for adsorption, which can provide abundant active binding sites for heavy metal ions through chemical modification.

KEY SCIENTIFIC CONCEPT OF REVIEW

As the most representative of biopolymer hydrogels, polysaccharide-based hydrogels are diverse, physically and chemically stable, and can undergo complex chemical modifications to enhance their performance, thus exhibiting superior ability to remove contaminants. This review summarizes the preparation methods of hydrogels, followed by a discussion of the main categories and applications of polysaccharide-based biopolymer hydrogels.

Green and Superior Adsorbents Derived from Natural Plant Gums for Removal of Contaminants: A Review

The ubiquitous presence of contaminants in water poses a major threat to the safety of ecosystems and human health, and so more materials or technologies are urgently needed to eliminate pollutants. Polymer materials have shown significant advantages over most other adsorption materials in the decontamination of wastewater by virtue of their relatively high adsorption capacity and fast adsorption rate. In recent years, "green development" has become the focus of global attention, and the environmental friendliness of materials themselves has been concerned. Therefore, natural polymers-derived materials are favored in the purification of wastewater due to their unique advantages of being renewable, low cost and environmentally friendly. Among them, natural plant gums show great potential in the synthesis of environmentally friendly polymer adsorption materials due to their rich sources, diverse structures and properties, as well as their renewable, non-toxic and biocompatible advantages. Natural plant gums can be easily modified by facile derivatization or a graft polymerization reaction to enhance the inherent properties or introduce new functions, thus obtaining new adsorption materials for the efficient purification of wastewater. This paper summarized the research progress on the fabrication of various gums-based adsorbents and their application in the decontamination of different types of pollutants. The general synthesis mechanism of gums-based adsorbents, and the adsorption mechanism of the adsorbent for different types of pollutants were also discussed. This paper was aimed at providing a reference for the design and development of more cost-effective and environmentally friendly water purification materials.

Recent developments of magnetic nanoadsorbents for remediation of arsenic from aqueous stream

One of the emerging environmental concerns is the high levels of arsenic ions found in groundwater and other water sources. Decontaminating water that contains arsenic is crucial for environmental and health reasons. Nano-adsorbents have gained much interest recently for the adsorptive removal of arsenic species from wastewater. On the other hand, for their prospective use in natural water treatment, current nano-adsorbents must be separated from treated fluids. Researchers studied nanocomposite iron oxide-based adsorbents to overcome these problems and to design effective sorbents for removing arsenic. This study provides a summary of current developments in the field of magnetic nanoadsorbents for the removal of various arsenic compounds from wastewater. Adsorption of arsenic from groundwater has been found to be very promising for magnetic nanoadsorbents. In order to eliminate arsenic from the aqueous phase, magnetic nanocomposite adsorbents may offer practical and affordable water purification solutions.

Adsorptive sequestration of noxious uranium (VI) from water resources: A comprehensive review

Groundwater is usually utilized as a drinking water asset everywhere. Therefore, groundwater defilement by poisonous radioactive metals such as uranium (VI) is a major concern due to the increase in nuclear power plants as well as their by-products which are released into the watercourses. Waste Uranium (VI) can be regarded as a by-product of the enrichment method used to produce atomic energy, and the hazard associated with this is due to the uranium radioactivity causing toxicity. To manage these confronts, there are so many techniques that have been introduced but among those adsorptions is recognized as a straightforward, successful, and monetary innovation, which has gotten major interest nowadays, despite specific drawbacks regarding operational as well as functional applications. This review summarizes the various adsorbents such as Bio-adsorbent/green materials, metal oxide-based adsorbent, polymer based adsorbent, graphene oxide based adsorbent, and magnetic nanomaterials and discuss their synthesis methods. Furthermore, this paper emphasis on adsorption process by various adsorbents or modified forms under different physicochemical conditions. In addition to this adsorption mechanism of uranium (VI) onto different adsorbent is studied in this article. Finally, from the literature reviewed conclusion have been drawn and also proposed few future research suggestions.

Magnetic nanocomposite adsorbents for abatement of arsenic species from water and wastewater

The presence of high concentrations of arsenic species in drinking water and other water bodies has become one of the most critical environmental concerns. Therefore, decontamination of arsenic-containing water is essential for improved health and environmental concern. In recent years, nano-adsorbents have been widely used for the adsorptive removal of arsenic from water. Separating existing nano-adsorbents from treated waters, on the other hand, is a critical issue for their potential applications in natural water treatment. To address these issues and to effectively remove arsenic from water, researchers looked at iron oxide-based magnetic nanocomposite adsorbents. The magnetic nanoadsorbents have the benefit of surface functionalization, making it easier to target a specific pollutant for adsorption, and magnetic separation. In addition, magnetic nanoparticles have a large surface area, high chemical inertness, superparamagnetic, high magnetic susceptibility, small particle size, and large specific surface area, and are especially easily separated in a magnetic field. Magnetic nano-adsorbents have been discovered to have a lot of potential for eliminating arsenic from water. The recent advances in magnetic nano-absorbents for the cleanup of arsenic species from water are summarized in this paper. Future perspectives and directions were also discussed in this article. This will help budding researchers for the further advancement of magnetic nanocomposites for the treatment of water and wastewater contaminated with arsenic.

Highly efficient poly(acrylic acid-co-aniline) grafted itaconic acid hydrogel: Application in water retention and adsorption of rhodamine B dye for a sustainable environment

The present study used a free radical co-polymerization approach to synthesize a smart hydrogel of itaconic acid grafted poly(acrylic acid-co-aniline) (ItA-g-poly(AA-co-ANi)). ItA-g-poly(AA-co-ANi) hydrogel was characterized by Fourier transform infrared spectroscopy (FT-IR), Raman, X-ray diffraction (XRD), thermogravimetric analysis (TGA), field emission scanning electron microscope (FE-SEM), and X-ray photoelectron spectroscopy (XPS) analysis. Rhodamine B (RhB) dye was removed from an aqueous medium using ItA-g-poly(AA-co-ANi) hydrogel. To determine the maximum adsorption, the effect of parameters such as initial dye concentration, contact time, pH, and adsorbent dose were examined. The ItA-g-poly(AA-co-ANi) hydrogel had a high swelling percentage of 1755.3%. The high water penetration of ItA-g-poly(AA-co-ANi) hydrogel with a high swelling rate exposed the internal adsorption sites for RhB dye adsorption. The adsorption performance of ItA-g-poly(AA-co-ANi) hydrogel was explained by the pseudo-first-order and Freundlich adsorption isotherm models. Moreover, after four adsorption-desorption cycles, the ItA-g-poly(AA-co-ANi) hydrogel maintained an adsorption efficiency of 85.2%. The high water retention ability of ItA-g-poly(AA-co-ANi) hydrogel improved the moisture maintenance limit of soil for irrigation up to 23 days. As a result, ItA-g-poly(AA-co-ANi) hydrogel can be used in the elimination of toxic dyes as well as in irrigation systems.

Electromagnetic field controlled domain wall displacement for induced strain tailoring in BaTiO3-epoxy nanocomposite

Failure in an epoxy polymer composite material is prone to initiate by the coalescence of microcracks in its polymer matrix. As such, matrix toughening via addition of a second phase as rigid or/and rubber nano/micro-particles is one of the most popular approaches to improve the fracture toughness across multiple scales in a polymer composite, which dissipates fracture energy via deformation mechanisms and microcracks arrest. Few studies have focused on tailorable and variable toughening, so-called ‘active toughening’, mainly suggesting thermally induced strains which offer slow and irreversible toughening due to polymer’s poor thermal conductivity. The research presented in the current article has developed an instantaneous, reversible extrinsic strain field via remote electromagnetic radiation. Quantification of the extrinsic strain evolving in the composite with the microwave energy has been conducted using in-situ real-time fibre optic sensing. A theoretical constitutive equation correlating the exposure energy to micro-strains has been developed, with its solution validating the experimental data and describing their underlying physics. The research has utilised functionalised dielectric ferroelectric nanomaterials, barium titanate (BaTiO₃), as a second phase dispersed in an epoxy matrix, able to introduce microscopic electro-strains to their surrounding rigid epoxy subjected to an external electric field (microwaves, herein), as result of their domain walls dipole displacements. Epoxy Araldite LY1564, a diglycidyl ether of bisphenol A associated with the curing agent Aradur 3487 were embedded with the BaTiO₃ nanoparticles. The silane coupling agent for the nanoparticles’ surface functionalisation was 3-glycidoxypropyl trimethoxysilane (3-GPS). Hydrogen peroxide (H₂O₂, 30%) and acetic acid (C₂H₄O₂, 99.9%) used as functionalisation aids, and the ethanol (C₂H₆O, 99.9%) used for BaTiO₃ dispersion. Firstly, the crystal microstructure of the functionalised nanoparticles and the thermal and dielectric properties of the achieved epoxy composite materials have been characterised. It has been observed that the addition of the dielectric nanoparticles has a slight impact on the curing extent of the epoxy. Secondly, the surface-bonded fibre Bragg grating (FBG) sensors have been employed to investigate the real-time variation of strain and temperature in the epoxy composites exposed to microwaves at 2.45 GHz and at different exposure energy. The strains developed due to the in-situ exposure at composite, adhesive and their holding fixture material were evaluated using the FBG. The domain wall induced extrinsic strains were distinguished from the thermally induced strains, and found that the increasing exposure energy has an instantaneously increasing effect on the development of such strains. Post-exposure Raman spectra showed no residual field in the composite indicating no remnant strain field examined under microwave powers < 1000 W, thus suggesting a reversible strain introduction mechanism, i.e. the composite retaining its nominal properties post exposure. The dielectric composite development and quantifications presented in this article proposes a novel active toughening technology for high-performance composite applications in numerous sectors.

Bentonite-based sodium alginate/ dextrin cross-linked poly (acrylic acid) hydrogel nanohybrids for facile removal of paraquat herbicide from aqueous solutions

Removal of hazardous herbicides from the aqueous solution is critical for overcoming health-related issues across the wider population. In the current work, we have prepared sodium alginate (SAlg), dextrin, and acrylic acid (AA) based cross-linked hydrogels, composed of bentonite incorporated in the biocompatible hydrogel matrix. This hydrogel composite can remove highly toxic herbicide paraquat (PQ). As-synthesised hydrogel (SAlg/dextrin-cl-PAA) and hydrogel composite (SAlg/dextrin-cl-PAA/bentonite) were further analysed by infra-red spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and thermogravimetric analysis (TGA/DSC). For the first time, PQ adsorption onto sodium and dextrin-based hydrogel was also evaluated. The measured highest removal capacities were 76.923 and 90.909 mg g^-1 for the SAlg/dextrin-cl-PAA and SAlg/dextrin-cl-PAA/bentonite, respectively. Pseudo-second-order (PSO) and Langmuir isotherm models have shown to be best suited for accurately describing the adsorption mechanism. A thermodynamics study verified that the adsorption of PQ on adsorbents is spontaneous, favourable and exothermic. Moreover, reusability analysis shows that the adsorbents possess good reproducibility even after six successive cycles. The adsorption results demonstrate that the synthesised adsorbents are very efficient for removing herbicides (PQ) from wastewater.

Nanofabrication route to achieve sustainable production of next generation defect-free graphene: analysis and characterisation

In the past two decades, graphene has been one of the most studied materials due to its exceptional properties. The scalable route to cost-effective manufacture defect-free graphene has continued to remain a technical challenge. Intrinsically defect-free graphene changes its properties dramatically, and it is a challenging task to control the defects in graphene production using scaled-down subtractive manufacturing techniques. In this work, the exfoliation of graphite was investigated as a sustainable low-cost graphene manufacturing technique. The study made use of a simple domestic appliance e.g., a kitchen blender to churn graphene in wet conditions by mixing with N-Methyl-2-pyrrolidone (NMP). It was found that the centrifugal force-induced turbulent flow caused by the rotating blades exfoliates graphite flakes to form graphene. The technique is endowed with a high yield of defect-free graphene (0.3 g/h) and was deemed suitable to remove 10% fluoride content from the water and color absorption from fizzy drinks.

A Short Review on the N,N-Dimethylacrylamide-Based Hydrogels

Scientists have been encouraged to find different methods for removing harmful heavy metal ions and dyes from bodies of water. The adsorption technique offers promising outcomes for heavy metal ion removal and is simple to run on a large scale, making it appropriate for practical applications. Many adsorbent hydrogels have been developed and reported, comprising N,N-dimethylacrylamide (DMAA)-based hydrogels, which have attracted a lot of interest due to their reusability, simplicity of synthesis, and processing. DMAA hydrogels are also a suitable choice for self-healing materials and materials with good mechanical properties. This review work discusses the recent studies of DMAA-based hydrogels such as hydrogels for dye removal and the removal of hazardous heavy metal ions from water. Furthermore, there are also references about their conduct for self-healing materials and for enhancing mechanical properties.

ZrO2 Nanoparticles and Poly(diallyldimethylammonium chloride)-Doped Graphene Oxide Aerogel-Coated Stainless-Steel Mesh for the Effective Adsorption of Organophosphorus Pesticides

A novel sorbent based on the ZrO₂ nanoparticles and poly(diallyldimethylammonium chloride)-modified graphene oxide aerogel-grafted stainless steel mesh (ZrO₂/PDDA-GOA-SSM) was used for the extraction and detection of organophosphorus pesticides (OPPs). Firstly, the PDDA and GO composite was grafted onto the surface of SSM and then freeze-dried to obtain the aerogel, which efficiently reduced the accumulation of graphene nanosheets. It integrated the advanced properties of GOA with a thin coating and the three-dimensional structural geometry of SSM. The modification of ZrO₂ nanoparticles brought a selective adsorption for OPPs due to the combination of the phosphate group as a Lewis base and ZrO₂ nanoparticles with the Lewis acid site. The ZrO₂/PDDA-GOA-SSM was packed into the solid-phase extraction (SPE) cartridge to extract OPPs. According to the investigation of different factors, the extraction recovery was mainly affected by the hydrophilic-hydrophobic properties of analytes. Effective extraction and elution parameters such as sample volume, sample pH, rate of sample loading, eluent, and eluent volume, were also investigated and discussed. Under the optimal conditions, the linearity of phoxim and fenitrothion was in the range of 1.0-200 μg L^-1, and the linearity of temephos was in the range of 2.5-200 μg L^-1. The limits of detection were ranged from 0.2 to 1.0 μg L^-1. This established method was successfully applied to detect OPPs in two vegetables. There was no OPP detected in real samples, and results showed that the matrix effects were in the range of 46.5%-90.1%. This indicates that the ZrO₂/PDDA-GOA-SSM-SPE-HPLC method could effectively extract and detect OPPs in vegetables.

Thermal, Mechanical and Electrical Properties of Carbon Fiber Fabric and Graphene Reinforced Segmented Polyurethane Composites

Thermal conductive materials with reliable and high performances such as thermal interface materials are crucial for rapid heat transferring in thermal management. In this work, carbon fiber fabric and graphene reinforced segmented polyurethane composites (CFF-G/SPU) were proposed and prepared to obtain superior thermal, mechanical and electrical properties using the hot-pressing method. The composites exhibit excellent tensile strength and can withstand a tensile force of at least 350 N without breaking. The results show that, comparing with the SPU material, the thermal conductivity is increased by 28% for the CFF-G/SPU composite, while the in-plane electrical conductivity is increased by 8 orders of magnitude to 175 S·m^-1. The application of CFF-G/SPU composite as a winding thermal interface material with electric-driven self-heating effect presents good performances of fluidity and interface wettability. The composite has great advantages in phase transition and filling the interfacial gap in the short time of few seconds under the condition of electrical field, with the interface temperature difference between two layers significantly reduced.