Antimicrobial, anticancer activities, molecular docking, and DFT/B3LYP/LANL2DZ analysis of heterocyclic cellulose derivative and their Cu-complexes.

In this study, novel Cu-complexes of heterocyclic cellulose which were synthesized via the reaction of carboxymethyl cellulose (CMC) from bagasse pulp with NH2NH2 to give hydrazide cellulose which easily reacted with CS2 to form salt and then cyclized in the presence of HCl to afford cellulose oxadiazole, or with hydrazine hydrate to give cellulose triazole. Furthermore, the cellulose oxadiazole and triazole moieties acting as chelating agents with metal ion Cu (II), and all synthesized compounds were examined for their spectral analysis to show the adsorption of Cu (II) on the surface of cellulose through intramolecular hydrogen bonding. Results illustrated that cellulose oxadiazole and Cu- cellulose oxadiazole exhibited antimicrobial activities more than triazole and Cu- cellulose triazole. Furthermore, anticancer results showed that both cellulose oxadiazole and triazole exhibited activity higher than Cu-cellulose oxadiazole and Cu-cellulose triazole, where the cellulose triazole showed the highest activity (IC50 = 58.7 µg/µL). Additionally, the docking simulation of the synthesized cellulose complexes with different proteins such as PDBID:3t88, PDBID:4ynt, PDBID:1tgh, PDBID:2wje, and PDBID:4hdq and shortage bond length to confirm the experimental results. Optimization of metal complexes utilized the DFT/B3LYP/LANL2DZ basis set to confirm the stability of these metals theoretically and their physical descriptors and FMO analysis.

Ionothermal Carbonization of Sugarcane Bagasse in 1-Alkyl-3-methylimidazolium Ionic Liquids: Insights into the Role of the Chloroferrate Anion.

We report the ionothermal carbonization (ITC) of lignocellulosic biomass in imidazolium tetrachloroferrate ionic liquids (ILs) as an advantageous approach for the preparation of nanostructured carbonaceous materials, namely, ionochars. In a previous study, we investigated the role of the imidazolium cation and demonstrated the possibility of controlling both the textural and morphological properties of ionochars by cation engineering. Although essential for providing intermediate Lewis acidity and relatively high thermal stability, the role of the chloroferrate anion is still open to debate. Herein, we investigated the ITC of sugarcane bagasse and its main component, cellulose, in 1-alkyl-3-methylimidazolium ILs with different chloroferrate anions. We identified anionic speciation and its impact on the properties of the IL by Raman spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. The obtained ionochars were characterized by gas physisorption, electron microscopy, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and 13C solid-state CP-MAS NMR spectroscopy. We show that the anionic species have a predominant impact on the textural and morphological properties of the ionochars.

Antibacterial activity and dielectric properties of the PVA/cellulose nanocrystal composite using the synergistic effect of rGO@CuNPs.

This work aims to enhance the performance of the polyvinyl alcohol (PVA) composite by using cellulose nanocrystal (CNC) as reinforcement and copper nanoparticles (CuNPs)/reduced graphene oxide (rGO) as conducting and antimicrobial reagents. Firstly, rGO was loaded onto CuNPs using an eco-friendly microwave method. Different techniques characterized the components and prepared composites, which indicated the incorporation of cellulose nanocrystals and rGO@CuNPs within the polyvinyl alcohol matrix. Utilizing the clear zone of inhibition, the antibacterial test was quantified. Compared to the neat composite, the rGO@CuNPs loaded polyvinyl alcohol/ cellulose nanocrystal composites exhibited no bacterial growth against S. aureus, E. coli, and C. albicans. However, all composites did not have antifungal activity against A. niger. The combination of conductivity and interfacial polarization is the reason for the abrupt increase of permittivity with decreasing frequency. Besides, adding rGO@CuNPs improved the electrical conductivity. DC-Conductivity increased about a decade after adding cellulose nanocrystal to polyvinyl alcohol, then another decade after adding CuONPs. The electric loss modulus representation shows a systematic shift in the peak position towards higher frequencies, decreasing the so-called conductivity relaxation time. This is the main reason for the enhancement of conductivity. The systematic attenuation of peaks' height with increasing conductivity is still unclear.

Potential application of hydroxypropyl methylcellulose/shellac embedded with graphene oxide/TiO2-Nps as natural packaging film.

Graphene oxide (GO), TiO2-NPs, HPMC, and shellac are environmentally green polymers and nanocomposites. This work aimed to create biodegradable composite films made of HPMC/shellac, HPMC/shellac-GO, and HPMC/shellac-GO/TiO2-NPs by film casting. TiO2-HPMC/shellac-GO matrix's dispersibility and mixing ability were characterized and observed using FTIR and XRD. XRD analysis shows that the crystallinity decreased within the composites due to breaking H-bonding. Compared to HPMC/shellac, TGA/DTG demonstrated the composite films' superior thermal stability. TiO2 (0.08-0.16 %) was cast into a composite film comprising HPMC, shellac, and GO. The homogeneity of TiO2 distribution in the composite film was shown using a SEM, which was also used to display the morphology of nanocomposite films. Nanocomposite films' thickness, air permeability, tensile strength, Young's modulus, and burst strength were examined. The results demonstrated that natural films prepared by a combination of shellac/GO with HPMC enhanced the fabricating of films' properties, the tensile strength increased by 231 % (from 16 to 53 MPa) in HPMC and HPSG2 (HPMC 1.9 g/shellac 0.25 g/GO 0.125 g in 100 mL) respectively, whereas the contact angle did not change. And after addition of TiO2-NPs, there were high enhancements in HPMC films' properties, such tensile strength increased by 212 % (from 16 to 50 MPa), burst strength increased by 20.96 % (3.1 to 3.75 Kg/cm2), and the contact angle by 60.86 % (48 to 74°) in HPMC and HPSGT2 respectively. Compared to HPMC films, films exhibited the highest levels of antibacterial activity against E. coli, B. mycoides, and C. albicans. So, the composite films from HPMC/shellac/GO/TiO2-NPs are promising potential packaging materials.

Exceptionally Fast Temperature-Responsive, Mechanically Strong and Extensible Monolithic Non-Porous Hydrogels: Poly(N-isopropylacrylamide) Intercalated with Hydroxypropyl Methylcellulose.

Exceptionally fast temperature-responsive, mechanically strong, tough and extensible monolithic non-porous hydrogels were synthesized. They are based on divinyl-crosslinked poly(N-isopropyl-acrylamide) (PNIPAm) intercalated by hydroxypropyl methylcellulose (HPMC). HPMC was largely extracted after polymerization, thus yielding a 'template-modified' PNIPAm network intercalated with a modest residue of HPMC. High contents of divinyl crosslinker and of HPMC caused a varying degree of micro-phase-separation in some products, but without detriment to mechanical or tensile properties. After extraction of non-fixed HPMC, the micro-phase-separated products combine superior mechanical properties with ultra-fast T-response (in 30 s). Their PNIPAm network was highly regular and extensible (intercalation effect), toughened by hydrogen bonds to HPMC, and interpenetrated by a network of nano-channels (left behind by extracted HPMC), which ensured the water transport rates needed for ultra-fast deswelling. Moreover, the T-response rate could be widely tuned by the degree of heterogeneity during synthesis. The fastest-responsive among our hydrogels could be of practical interest as soft actuators with very good mechanical properties (soft robotics), while the slower ones offer applications in drug delivery systems (as tested on the example of Theophylline), or in related biomedical engineering applications.

Microwave-Prepared Quantum Dots and Their Potential Applications as Adsorbents and Chemosensors.

A combination of different eco-friendly materials prepared promising fluorescent quantum dots (QDs) through the one-step process using the microwave heating of urea with cellulose, chitosan, and biochar. Characterizations of the prepared QDs, including the investigation of their structure by infrared spectroscopy, Raman analysis, X-ray diffraction, thermal gravimetric analysis, morphology, and optical properties, were performed. The results showed that QDs possess a small size, high UV absorption, and excitation wavelength-dependent fluorescence. The prepared QDs were also tested for metal ions removal from aqueous solutions. The adsorption at different contact times was investigated to optimize the adsorption efficiency of the prepared QDs. All QDs were found to be an ideal sorbent for Cr(II), Cu(II), Mn(II), and Pb(II). From the data, Cr(II) was more highly adsorbed than other metal ions. The results of the kinetic investigation showed that the pseudo-second-order kinetic model fit the adsorption process effectively. In addition, the fluorescence spectra of QDs were changed after the adsorption of metal ions; hence, the prepared QDs could be utilized in environmental sectors such as wastewater pollution detection, adsorption, and chemical sensing applications.

Sustainable grafted chitosan-dialdehyde cellulose with high adsorption capacity of heavy metal.

A novel adsorbent was prepared using a backbone comprising chemically hybridized dialdehyde cellulose (DAC) with chitosan via Schiff base reaction, followed by graft copolymerization of acrylic acid. Fourier transform infrared spectroscopy (FTIR) confirmed the hybridization while scanning electron microscopy (SEM) revealed intensive covering of chitosan onto the surface of DAC. At the same time, energy dispersive X-ray (EDX) proved the emergence of nitrogen derived from chitosan. The X-ray diffraction (XRD) indicated that the crystallinity of the backbone and graft copolymer structures was neither affected post the hybridization nor the grafting polymerization. The adsorbent showed high swelling capacity (872%) and highly efficient removal and selectivity of Ni2+ in the presence of other disturbing ions such as Pb2+ or Cu2+. The kinetic study found that the second-order kinetic model could better describe the adsorption process of (Cu2+, Ni2+) on the graft copolymer. In contrast, the first-order kinetic model prevails for the binary mixture (Pb2+, Ni2+). Moreover, the correlation coefficient values for the adsorption process of these binary elements using Langmuir and Freundlich isotherms confirmed that the developed grafted DAC/chitosan exhibits a good fit with both isotherm models, which indicates its broadened and complicated structure. Furthermore, the grafted DAC/chitosan exhibited high efficient regeneration and high adsorption capacity for Pb2+, Cu2+ and Ni2+.

Anatase-cellulose acetate for reinforced desalination membrane with antibacterial properties.

This study aimed to prepare antifouling and highly mechanical strengthening membranes for brackish and underground water desalination. It was designed from cellulose acetate (CA) loaded anatase. Anatase was prepared from tetra-iso-propylorthotitanate and carboxymethyl cellulose. Different concentrations of anatase (0.2, 0.3, 0.5, 0.6, 0.7, and 0.8)% were loaded onto CA during the inversion phase preparation of the membranes. The prepared membranes were characterized using Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM & EDX), mechanical properties, swelling ratio, porosity determination, and ion release. The analysis confirmed the formation of anatase on the surface and inside the macro-voids of the membrane. Furthermore, anatase loading improved the CA membrane's mechanical properties and decreased its swelling and porosity rate. Also, CA-loaded anatase membranes displayed a significant antibacterial potential against Gram-positive and Gram-negative bacteria. The results showed that the salt rejection of the CA/anatase films as-prepared varies considerably with the addition of nanomaterial, rising from 46%:92% with the prepared membranes under the 10-bar operation condition and 5 g/L NaCl input concentration. It can be concluded that the prepared CA-loaded anatase membranes have high mechanical properties that are safe, economical, available, and can stop membrane biofouling.

Microwave-assisted synthesis of amphoteric fluorescence carbon quantum dots and their chromium adsorption from aqueous solution.

The chromium adsorption behavior from aqueous solution by the amphoteric Janus nitrogen-doped carbon quantum dots (AJ-N-CQDs) was investigated. The pseudo-first-order and the second-order adsorption kinetics models were employed to analyze the experimental data; the second-order adsorption kinetics model presented a better correlation to the experimental data, suggesting a chemisorptions process. The values obtained in the pseudo-first-order are still suitable for describing the Kinetics of Cr(VI) sorption. These values elucidate the surface processes involving chemisorption and physisorption in the adsorption of Cr(VI) by AJ-N-CQDs. The R2 of the Boyd model gave a better fit to the adsorption data of AJ-N-CQDs (i.e., external diffusion), which means the surface processes involving external Cr(VI) adsorption by AJ-N-CQDs. The higher value of α may be due to the greater surface area of the AJ-N-CQDs for the immediate adsorption of Cr(VI) from the aqueous solution. AJ-N-CQDs have fluorescence spectra before and after Cr(VI) adsorption, indicating they are promising for chemical sensor applications.

Sulfate-reducing bacteria loaded in hydrogel as a long-lasting H2S factory for tumor therapy.

The continuous supply of hydrogen sulfide (H2S) gas at high concentrations to tumors is considered a promising and safe strategy for tumor therapy. However, the absence of a durable and cost-effective H2S-producing donor hampers its extensive application. Sulfate-reducing bacteria (SRB) can serve as an excellent H2S factory due to their ability to metabolize sulfate into H2S. Herein, a novel injectable chondroitin sulfate (ChS) hydrogel loaded with SRB (SRB@ChS Gel) is proposed to sustainably produce H2S in tumor tissues to overcome the limitations of current H2S gas therapy. In vitro, the ChS Gel not only supports the growth of encapsulated SRB, but also supplies a sulfate source to the SRB to produce high concentrations of H2S for at least 7 days, resulting in mitochondrial damage and immunogenic cell death. Once injected into tumor tissue, the SRB@ChS Gel can constantly produce H2S for >5 days, significantly inhibiting tumor growth. Furthermore, such treatment activates systemic anti-tumor immune responses, suppresses the growth of distant and recurrent tumors, as well as lung metastases, meanwhile with negligible side effects. Therefore, the injectable SRB@ChS Gel, as a safe and long-term, self-sustained H2S-generating factory, provides a promising strategy for anti-tumor therapy.

New antibacterial hydrogels based on sodium alginate.

Nowadays, the combined knowledge and experience in biomedical research and material sciences results in the innovation of smart materials that could efficiently overcome the problems of microbial contaminations. Herein, a new drug delivery platform prepared by grafting sodium alginate with ß-carboxyethyl acrylate and acrylamide was described and characterized. 9-Aminoacridine (9-AA), and kanamycin sulfate (KS) were separately loaded into the hydrogel in situ during graft polymerization. The grafting efficiency for the resulting hydrogels was 70.01-78.08 %. The chemical structure of the hydrogels, thermogravimetric analysis, and morphological features were investigated. The swelling study revealed that the hydrogel without drugs achieved a superior swelling rate compared to drug-loaded hydrogels. The hydrogel tuned the drug-release rate in a pH-dependent manner. Furthermore, the antibacterial study suggested that the hydrogels encapsulating 9-AA (88.6 %) or KS (89.3 %) exhibited comparable antibacterial activity against Gram-positive and Gram-negative bacterial strains. Finally, the cytocompatibility study conducted on normal lung cell line (Vero cells) demonstrated neglectable to tolerable toxicity for the drug-loaded hydrogel. More interestingly, the cell viability for the blank hydrogel was 92.5 %, implying its suitability for biomedical applications.

Bimetallic hydrogels based on chitosan and carrageenan as promising materials for biological applications.

In this study, novel crosslinked hydrogels based on chitosan (CS) and carrageenan (CRG) loaded with silver and/or copper nanoparticles (Ag/CuNPs) were prepared through a freeze-drying (thawing) process to be applied in biological applications comprising wound dressing. These hydrogels showed porous interconnected structures. The influence of the used nanoparticles (NPs) on the antibacterial properties of the CS/CRG hydrogels was explored. Antimicrobial results revealed that both CS/CRG/CuNPs, CS/CRG/AgNPs, and CS/CRG/Ag-CuNPs exhibited promising antibacterial and antifungal activity against Escherichia coli, Pseudomonas aeruginosa, Streptococcus mutans, Staphylococcus aureus, Bacillus subtilis, and Candida albicans. Moreover, CS/CRG/AgNPs, CS/CRG/CuNPs, and CS/CRG/Ag-CuNPs hydrogels showed potential antioxidant activity to be 57%, 78%, and 89%, respectively. Furthermore, cytotoxicity results against Vero normal cell line confirmed that all designed hydrogels are safe upon usage. The bimetallic CS/CRG hydrogels showed notably enhanced antibacterial properties among the as-prepared hydrogels allowing them to be a successful material upon being employed in wound dressing applications.

Insight into TEMPO-oxidized cellulose-based composites as electrochemical sensors for dopamine assessment.

The diagnosis and treatment of many neurological and psychiatric problems depend on establishing simple, inexpensive, and comfortable electrochemical sensors for dopamine (DA) detection. Herein, 2,2,6,6 tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TOC) were successfully loaded with silver nanoparticles (AgNPs) and/or graphite (Gr) and crosslinked by tannic acid, producing composites. This study describes a suitable casting procedure for the composite synthesis of TOC/AgNPs and/or Gr for the electrochemical detection of dopamine. Electrochemical impedance spectra (EIS), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were employed to characterize the TOC/AgNPs/Gr composites. In addition, the direct electrochemistry of electrodes treated with the prepared composites was examined using cyclic voltammetry. The TOC/AgNPs/Gr composite-modified electrode improved electrochemical performance towards detecting dopamine compared to TOC/Gr-modified electrodes. Upon employing amperometric measurement, our electrochemical instrument has a wide linear range (0.005-250 µM), a low limit of detection (0.0005 µM) at S/N = 3, and a high sensitivity (0.963 µA µM-1 cm-2). Additionally, it was demonstrated that DA detection seemed to have outstanding anti-interference characteristics. The proposed electrochemical sensors meet the clinical criteria regarding reproducibility, selectivity, stability, and recovery. The straightforward electrochemical method utilized in this paper may provide a potential framework for creating dopamine quantification biosensors.

Wound Dressings Based on Sodium Alginate-Polyvinyl Alcohol-Moringa oleifera Extracts.

Biopolymers have significant pharmaceutical applications, and their blending has favorable characteristics for their pharmaceutical properties compared to the sole components. In this work, sodium alginate (SA) as a marine biopolymer was blended with poly(vinyl) alcohol (PVA) to form SA/PVA scaffolds through the freeze-thawing technique. Additionally, polyphenolic compounds in Moringa oleifera leaves were extracted by different solvents, and it was found that extracts with 80% methanol had the highest antioxidant activity. Different concentrations (0.0-2.5%) of this extract were successfully immobilized in SA/PVA scaffolds during preparation. The characterization of the scaffolds was carried out via FT-IR, XRD, TG, and SEM. The pure and Moringa oleifera extract immobilized SA/PVA scaffolds (MOE/SA/PVA) showed high biocompatibility with human fibroblasts. Further, they showed excellent in vitro and in vivo wound healing capacity, with the best effect noted for the scaffold with high extract content (2.5%).

Temperature- and pH-Responsive Super-Absorbent Hydrogel Based on Grafted Cellulose and Capable of Heavy Metal Removal from Aqueous Solutions.

In this work, we prepared highly swelling, stimuli-responsive hydrogels capable of the highly efficient adsorption of inorganic pollutants. The hydrogels were based on hydroxypropyl methyl cellulose (HPMC) grafted with acrylamide (AM) and 3-sulfopropyl acrylate (SPA) and were synthesized via the growth (radical polymerization) of the grafted copolymer chains on HPMC, which was activated by radical oxidation. These grafted structures were crosslinked to an infinite network by a small amount of di-vinyl comonomer. HPMC was chosen as a cheap hydrophilic and naturally sourced polymer backbone, while AM and SPA were employed to preferentially bond coordinating and cationic inorganic pollutants, respectively. All the gels displayed a pronounced elastic character, as well as considerably high values of stress at break (several hundred %). The gel with the highest fraction of the ionic comonomer SPA (with an AM/SPA ratio = 0.5) displayed the highest equilibrium swelling ratio (12,100%), the highest volume response to temperature and pH, and the fastest swelling kinetics, but also the lowest modulus. The other gels (with AM/SPA = 1 and 2) displayed several times higher moduli but more modest pH responses and only very modest temperature sensitivity. Cr(VI) adsorption tests indicated that the prepared hydrogels removed this species from water very efficiently: between 90 and 96% in one step. The hydrogels with AM/SPA ratios of 0.5 and 1 appeared to be promising regenerable (via pH) materials for repeated Cr(VI) adsorption.

Advances in the Physico-Chemical, Antimicrobial and Angiogenic Properties of Graphene-Oxide/Cellulose Nanocomposites for Wound Healing.

Graphene oxide (GO) and its reduced form (rGO) have recently attracted a fascinating interest due to their physico-chemical properties, which have opened up new and interesting opportunities in a wide range of biomedical applications, such as wound healing. It is worth noting that GO and rGO may offer a convenient access to its ready dispersion within various polymeric matrices (such as cellulose and its derivative forms), owing to their large surface area, based on a carbon skeleton with many functional groups (i.e., hydroxyl, carboxyl, epoxy bridge, and carbonyl moieties). This results in new synergic properties due to the presence of both components (GO or rGO and polymers), acting at different length-scales. Furthermore, they have shown efficient antimicrobial and angiogenic properties, mostly related to the intracellular formation of reactive oxygen species (ROS), which are advantageous in wound care management. For this reason, GO or rGO integration in cellulose-based matrixes have allowed for designing highly advanced multifunctional hybrid nanocomposites with tailored properties. The current review aims to discuss a potential relationship between structural and physico-chemical properties (i.e., size, edge density, surface chemistry, hydrophilicity) of the nanocomposites with antimicrobials and angiogenic mechanisms that synergically influence the wound healing phenomenon, by paying particular attention to recent findings of GO or rGO/cellulose nanocomposites. Accordingly, after providing a general overview of cellulose and its derivatives, the production methods used for GO and rGO synthesis, the mechanisms that guide antimicrobial and angiogenic processes of tissue repair, as well as the most recent and remarkable outcomes on GO/cellulose scaffolds in wound healing applications, will be presented.

Preparation and performance of bionanocomposites based on grafted chitosan, GO and TiO2-NPs for removal of lead ions and basic-red 46.

Wastewater rich in heavy metals and organic compounds represents one of the essential environmental pollutants. Therefore, a practical approach is to fabricate eco-friendly polymer-based systems with a high ability to absorb pollutants. Herein, bionanocomposites consisting of chitosan (Cs) grafted by various monomers, such as acrylamide (Am), acrylic acid (AA), and 4-styrene sulfonic acid (SSA), and hybrid nanoparticles of graphene oxide/titanium dioxide nanoparticles (GO@TiO2-NPs) were fabricated. The prepared nanomaterials and bionanocomposites characterized via various tools. The data illustrated that the prepared GO had a thickness of 10 nm and TiO2-NPs had a diameter of 25 nm. In addition, the grafted chitosan (gCs) using Am and SSA had the largest surface area (gCs2; 22.89 nm) and its bionanocomposite (NC5; 104.79 nm). In addition, the sorption ability of the 0.15 g of prepared bionanocomposites to the (100 mg/L) of lead ions (Pb2+) and (25 mg/L) of basic-red 46 (BR46) under various conditions has been studied. The results showed that gCs3 and NC5 had the highest adsorption of Pb2+ (79.54 %) and BR46 (79.98 %), respectively. The kinetic study results of the sorbents obeyed the Pseudo second-order model. In contrast, the isothermal study followed the Freundlich adsorption model for Pb2+ and the Langmuir adsorption model for BR46.

Polyanionic electrically conductive superabsorbent hydrogel based on sodium alginate-g-poly (AM-co-ECA-co-AMPS): Broadband dielectric spectroscopy investigations.

In this study, the dielectric behavior of polyanionic electrically conductive superabsorbent hydrogel based on sodium alginate-g-poly(AM-co-ECA-co-AMPS) was investigated by broadband dielectric spectroscopy (BDS). The dielectric spectra obtained from -70 to 70 °C showed a superposition of three distinctive processes, electrode polarization, charge carrier's transport, and a molecular relaxation process. These dynamic processes were further analyzed along with the effect of both temperature and reduced graphene oxide (rGO) content. The development of a clear electrochemical double layer (ECDL) at the electrode/hydrogel interface strongly supports its possible application in supercapacitors' forms of energy storage. TGA, DSC, rheology, and electrochemical properties were studied. Furthermore, when the composite hydrogel with rGO content of 2.5 % was assembled into a symmetric supercapacitor, it displayed a specific capacitance of 756 F.g-1 at 1 A.g-1 and 704 F.g-1 after 5000 cycles with high capacitance retention of 93.2 %. The superior conductivity and porous structure of the rGO composite hydrogel are credited with the hydrogel's excellent electrochemical capabilities.

Eco-friendly Synthesis of Carbon Quantum Dots as an Effective Adsorbent.

Fluorescent carbon quantum dots (CQDs) were prepared by an economical, green, and single-step procedure with the assistance of microwave heating of urea with bagasse (SCB), cellulose (C), or carboxymethyl cellulose (CMC). The prepared CQDs were characterized using a series of spectroscopic techniques, and they had petite size, intense absorption in the UV, and excitation wavelength-dependent fluorescence. The prepared CQDs were used for Pb(II) adsorption from an aqueous solution. The removal efficiency percentages (R %) were 99.16, 96.36, and 98.48% for QCMC, QC, and QSCB, respectively. The findings validated the efficiency of CQDs synthesized from CMC, cellulose, and SCB as excellent materials for further utilization in the environmental fields of wastewater pollution detection, adsorption, and chemical sensing applications. The kinetics and isotherms studied found that all CQDs isotherms fit well with the Langmuir model than Freundlich and Temkin models. According to R2, the pseudo-second-order fits the adsorption of QCMC, while the first-order one fits with QC and QSCB.

High performance hydrogel electrodes based on sodium alginate-g-poly(AM-c o-ECA-co-AMPS for supercapacitor application.

Electrochemical conductive hydrogels are being extensively explored in the fabrication of portable batteries and high-performance supercapacitors. Herein, the rational design of a new polyanionic electrically conductive hydrogels based on sodium alginate-g-poly(AM-co-ECA-co-AMPS) are described. rGO was incorporated into the hydrogel during the polymerization process generating rGO@ sodium alginate-g-poly(AM-co-ECA-co-AMPS) composite hydrogels to study the impact of rGO on the performance of the hydrogels. FT-IR, XRD, and SEM-EDX characterized the chemical composition, crystalline, and morphological structure of the new synthesized hydrogels. The electrochemical performance of as-synthesized hydrogels was investigated by cyclic voltammetry, galvanostatic, charge-discharge rate, and electrochemical impedance spectroscopy. The supercapacitor performance for ECH2.5 composite hydrogel showed a capacitance of 753 F. g-1 at 1 A. g-1 with good rate capability and cycling stability up to 5000 cycles. Thus, ECH2.5 hydrogel is a good candidate as electrode material in supercapacitor applications.