Search

Herein, we report the designing of a C3N4/BiOI heterostructure that is supported on gum acacia-crosslinked-poly(acrylamide) hydrogel to fabricate a novel nanocomposite hydrogel. The potential application of the obtained nanocomposite hydrogel to remediate crystal violet dye (CVD) in an aqueous solution was explored. The structural and functional analysis of the nanocomposite hydrogel was performed by FTIR (Fourier transform infrared spectroscopy), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The different reaction parameters, such as CVD concentration, nanocomposite hydrogel dosage, and working pH, were optimized. The C3N4/BiOI heterostructure of the nanocomposite hydrogel depicts Z-scheme as the potential photocatalytic mechanism for the photodegradation of CVD. The degradation of CVD was also specified in terms of COD and HR-MS analysis was carried to demonstrate the major degradation pathways. [ABSTRACT FROM AUTHOR]

Rapid increase in use of fungicides for the agricultural and industrial purposes has marked the deterioration of water resources which ultimately affects the human life. Accordingly, various attempts have been made in the removal of these noxious compounds. In the same context, we are presenting biopolymers based nanohydrogel sheets; guar gum- crosslinked -Soya lecithin nanohydrogel sheets (GG- crosslinked -SY NHS) used for the effective removal of a fungicide; thiophanate methyl from aqueous solution. Guar gum and soya lecithin were employed as the biopolymers in the fabrication of nanohydrogel sheets due to their non- toxic nature, easy availability, cheapness and significant properties. Due to the presence of highly reactive functional groups onto the surface of GG- crosslinked -SY NHS, good adsorption results have been obtained. Maximum adsorption capacity of 59.205 mg/g was observed with 20 mg GG- crosslinked -SY NHS and 25 ppm thiophanate methyl solution concentration as calculated from the Langmuir isotherm. Results showed that neutral pH favoured the adsorption process. Kinetics results were indicative of the physical interactions between the thiophanate methyl and GG- crosslinked -SY NHS surface. Thermodynamic results have shown the spontaneous and endothermic adsorption process. [ABSTRACT FROM AUTHOR]

In the present work, a nanocomposite hydrogel is designed consisting of gum acacia, poly(acrylamide) and carbon nitride by facile microwave approach. This nanocomposite hydrogel is sensitive to environmental stimuli which is essential for its application in environmental remediation and as a drug delivery system. The effects of carbon nitride percentage and microwave Watt variation on swelling capacity of gum acacia‐cl‐poly(acrylamide)@carbon nitride (Ga‐cl‐PAM@C3N4) nanocomposite hydrogel are analyzed. The structural characterizations are considered by numerous techniques such as FTIR (Fourier transform infra‐red spectroscopy), X‐ray diffraction, transmission electron microscopy, scanning electron microscopy, and elemental mapping. Batch experiment is performed for remediation of ciprofloxacin (CIP) drug from water. Various parameters such as effect of ciprofloxacin doses, Ga‐cl‐PAM@C3N4 nanocomposite hydrogel dosage, pH, time and temperature for adsorption of CIP on gum acacia‐cl‐poly(acrylamide)@carbon nitride nanocomposite hydrogel is examined. Maximum adsorption capacity of Ga‐cl‐PAM@C3N4 nanocomposite hydrogel observed is 169.49 mg g−1 at pH 6.4. The drug loading and drug release capacity of Ga‐cl‐PAM@C3N4 nanocomposite hydrogel is investigated for ciprofloxacin. Drug release is monitored in artificial ocular solution (pH 8), saline (pH 5.5), acetate buffer (pH 2.2), and distilled water. Maximum drug release is observed in artificial ocular solution. [ABSTRACT FROM AUTHOR]

In this study, we have synthesized a starch/poly(alginic acid-cl-acrylamide) nanohydrogel (ST/PL(AA-c!-AAm) NHG) by co-polymerization method which was used as an effective adsorbent for the removal of coomassie brilliant (CB) blue R-250 dye from the aqueous solution. The synthesized nanohydrogel was characterized by FTIR, SEM and TEM techniques. The effect of initial dye concentration, temperature, and agitation time on the adsorption ability of the nanohydrogel was studied comprehensively. The experimental outcomes exhibited that the prepared nanohydrogel had high adsorption tendency to remove the CB from the aqueous solution. The regression coefficient values for Langmuir (0.99), Frendluich (0.93) and Tempkin (0.98) recommended that adsorption process fit to langmuir isotherm. The pseudo-second-order equation showed the better adsorption kinetics of the adsorption process. The feasibility of CB adsorption onto ST/PL(AA-cI-AAm) NHG was also studied thermodynamically and the results indicated that the adsorption was spontaneous and chemical in nature. [ABSTRACT FROM AUTHOR]

Polysaccharide-based hydrogels offer a great overlook for environmental applications and help in the elimination of various noxious pollutants from the water system. Novel carrageenan and itaconic acid-based superadsorbent hydrogel having appreciable swelling properties and adsorption capacity towards Methylene blue (MB), Crystal violet (CV), and Methyl Red (MR) was synthesized by suspension polymerization technique. The swelling study showed the dependency upon the temperature in which the swelling rate increased with increasing temperature with a maximum swelling rate of 417% at 318 K. For ascertaining the maximum adsorption capacity, various influential parameters such as contact time, adsorbent dose, dye concentration, and temperature were systematically studied. Maximum adsorption capacity as calculated from the Langmuir isotherm was 2439.02, 1111.11, and 666.68 mg/g for MB, CV, and MR, respectively. Thermodynamic studies revealed the spontaneous nature of the undertaken dye adsorption experiment. Overall, the present study reveals that the synthesized superadsorbent hydrogel can be used as an efficient adsorbent for the removal of dyes from an aqueous solution. [Display omitted] • Superadsorbent hydrogel designed for the adsorptive removal of cationic dyes. • Maximum adsorption capacity obtained for MB followed by CV and MR. • Results have been analyzed by isotherm and kinetic studies. • Superadsorbent hydrogel successfully recycled for consecutive 5 cycles. [ABSTRACT FROM AUTHOR]

Nanocomposite hydrogels are polymeric networks that possess a unique property of hydration. The presence of alcohols, carboxylic acids and amides as hydrophilic moieties in structure of nanocomposite hydrogels enhances their stiffness and water-absorbing capacity. Addition of cross-linker in the synthesis of hydrogels increases their stability under extreme conditions of temperature, pH and pressure. Natural polymer-based nanocomposite hydrogels are biodegradable, highly hydrophilic and possess good mechanical strength. Gelatin, chitin, cellulose, pectin, carrageenan, starch and alginate are natural polymers commonly used to fabricate nanocomposite hydrogels. Nanocomposite hydrogels have special characteristics such as high swelling rate, selectivity and stimuli-sensitive nature. Here we review nanocomposite hydrogels for environmental protection and biomedical engineering. Applications in biomedical engineering include drug delivery agents, wound dressing, tissue engineering and antibacterials. Applications in environmental protection include ion exchangers, adsorption, photocatalysis and soil conditioning. Many nanocomposite hydrogels show excellent adsorption selectivity for heavy metal ions: Cu2+ up to 30.35 mg/g, Pb2+ up to 35.94 mg/g, and Zn2+ and Fe3+ up to 94.34 mg/g. Xanthan gum-based nanocomposite hydrogel has removed 96% dye from industrial effluent as reported. In addition, most of the nanocomposite hydrogels showed better adsorption capacity for pollutants in the pH range from 5 to 7. The nanocomposite hydrogels could also be regenerated and successfully utilized for several times. Nanocomposite hydrogels are therefore good bio-absorbent materials for environmental detoxification. [ABSTRACT FROM AUTHOR]

In this study, chitosan- crosslinked -poly (alginic acid) nanohydrogel ( CN-cl-PL(AA) NHG) was synthesized by co-polymerization method. It was used an effective adsorbent for the exclusion of Cr(VI) metal ion from aqueous medium. The synthesized nanohydrogel was characterized by FTIR, SEM and TEM. The TEM images clearly indicated the appearance of smooth surface with average size of particles ranging from 30 to 80 nm. The effect of different adsorption parameters like agitation time, temperature, initial metal ion concentration and adsorbent dosage was studied and optimized. The results demonstrated that the prepared chitosan- crosslinked -poly (alginic acid) nanohydrogel had high adsorption tendency for the removal of Cr(VI) from the aqueous solution. The pseudo-second-order equation represented the better adsorption kinetics for the adsorption process. The thermodynamic studies showed the adsorption of Cr(VI) onto CN-cl-PL(AA) NHG was spontaneous and chemical in nature. [ABSTRACT FROM AUTHOR]