Showing papers by "Balbir Singh Kaith published in 2018"

Fabrication of Biodegradable Superabsorbent Using RSM Design for Controlled Release of KNO 3

Abstract: Present study envisaged the sequential experimental design approach for the development of biodegradable Gelatin-Tapoica/polyacrylamide superabsorbent. Percentage water uptake efficacy of candidate sample was optimized using Response Surface Methodology (RSM) design under microwave irradiation. Different process variables such as potassium persulphate and ammonium persulphate (KPS:APS) ratio, pH, reaction time concentration of acrylamide and N,N-methylene-bis-acrylamide (MBA) were investigated as a function of percentage swelling using sequential experimental design. Maximum liquid efficacy of 1550% was obtained at KPS:APS = 1.0:0.5; acrylamide = 7.67 × 10−1 mol L−1; MBA = 1.76 × 10−2 mol L−1; pH 10 and time = 110 s. The 3D crosslinked network formed was characterized using Fourier Transformation Infrared spectroscopy (FTIR), X-ray diffraction (XRD), Scanning Electron Microscopic (SEM) techniques and thermal stability was ensured by Thermal gravimetric Analysis/Differential Thermal Analysis/Differential Thermal Gravimetric (TGA/DTA/DTG) studies. Superabsorbent synthesized could increase the moisture content in different type of soils and was found to enhance the water-holding capability of the soil upto 60 days in clayey, 40 days in sandy and 51 days in mixture of two soils under controlled conditions. Further, candidate polymer was investigated for the in-vitro controlled release of the KNO3 with diffusion exponent ‘n’ was found to be 0.4326 indicating Fickian type diffusion. Also, initial diffusion coefficient (DI = 3.49 × 10−5 m2 h−1) was found to be greater than the lateral diffusion coefficient (DL = 3.76 × 10−6 m2 h−1) indicated rapid release of KNO3 during initial hours with slow release afterwards. The ecofriendly nature of the synthesized polymer was also tested by conducting biodegradation studies and it was found to degrade upto 94% and 88.1% within 70 days with degradation rate of 1.34 and 1.26% per day using composting method and vermicomposting method respectively. So, the synthesized candidate polymer was found to be boon for agriculture-horticulture sector with wide applicability.

RSM-CCD optimized In-air synthesis of photocatalytic nanocomposite: Application in removal-degradation of toxic brilliant blue

Abstract: The present research work describes the synthesis of a nanocomposite hydrogel [BFO/Mr-cl-poly(AAm)-IPN-poly(AA)] from nano bismuth iron oxide (BFO) synergistically coupled with interpenetrating network (IPN: Mr-cl-poly(AAm)-IPN-poly(AA)) of acrylic acid (AA) created within crosslinked network of a semi-IPN (Mr-cl-poly(AAm)). Semi-IPN was previously synthesized from N, N′-methylene bisacrylamide (MBA) crosslinked (cl) network of polyacrylamide (poly(AAm)) grafted onto aqueous extract of Commiphora mukul (Mr). The synthesized sample was efficient in removal-degradation of Coomassie brilliant blue G-250 (CBB) dye. Nanocomposite (NC) was magnetic as well as photocatalytic. Initially, optimization of the reaction parameters was carried out using Response Surface Methodology (RSM) design. Significant variables were accessed using Minimum Resolution V design and further optimized conditions were evaluated with central composite design (CCD). Semi-IPN showed maximum % swelling of 833.8% showing interdependence of time-temperature and solvent-crosslinker concentration. IPN synthesized gave maximum swelling of 285.8%. On insertion of BFO nanoparticles, the NC synthesized could remove-degrade a maximum of 90.4% dye in sunlight and 88.6% in UV–visible light under optimized parameters: 600 mg NC dose, 10 ppm initial dye concentration, pH 7.0, removal and degradation time 25 h and 4 h, respectively. The whole process showed second order kinetics with Elovich model criteria and followed Langmuir adsorption isotherm. GC-MS analysis gave low molecular weight products as an evidence of degradation process. Also, the NC synthesized can be recycled for industrial use.

Microwave-assisted synthesis of biodegradable interpenetrating polymer network of aloe vera–poly(acrylic acid- co -acrylamide) for removal of malachite green dye: equilibrium, kinetics and thermodynamic studies

Abstract: The present work deals with the synthesis of a biodegradable interpenetrating polymer network (IPN) consisting of natural polysaccharide aloe vera, acrylamide and acrylic acid. Biodegradability of the synthesized IPN was studied through soil burial and composting methods. The synthesized IPN was completely degraded within 70 days through the composting method and showed 91% degradation within 77 days through the soil burial method. Evidence of biodegradation of the synthesized IPN was studied by different techniques, for instance Fourier infrared spectroscopy and scanning electron microscopy. The synthesized IPN was used as a device for the removal of malachite green dye. The effect of different reaction parameters on IPN synthesis and dye removal was investigated. The maximum dye adsorption occurred at pH 4.5, because at this pH methylene green dye molecules are present in monomeric state. The result of Weber–Morris intra-particle diffusion showed that the rate-limiting step was not the intra-particle diffusion. The adsorption isotherm models, i.e., Langmuir, Freundlich, Dubinin–Radushkevich, Temkin, Redlich–Peterson and Sips, were studied and it was found that the Langmuir was the best-fitting model for the experimental data. An increase in temperature resulted in a decrease in malachite green dye removal, suggesting that the adsorption process was exothermic in nature. This synthesis is important from industrial viewpoints.

Synthesis of a biodegradable interpenetrating polymer network of Av-cl-poly(AA-ipn-AAm) for malachite green dye removal: kinetics and thermodynamic studies

Abstract: This paper deals with the synthesis of a biodegradable interpenetrating polymer network (IPN) from the natural polysaccharide aloe vera (Av), acrylamide (AAm) and acrylic acid (AA), and its evaluation as a dye removal device. In the synthesis of Av-cl-poly(AA-ipn-AAm), ammonium persulfate (APS) was used as an initiator, N,N′-methylene bisacrylamide (MBA) as a cross-linker, AA and AAm as primary and secondary monomers, respectively. Soil burial and composting methods were used to study the biodegradability of the synthesized IPN and the results showed 94% degradation within 70 days using the composting method and 86% degradation within 77 days using the soil burial method. Biodegradation was confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The synthesized IPN was used as a device for the removal of malachite green (MG) dye from aqueous solution. The maximum MG removal capacity of the synthesized IPN was found to be 97.3% under the optimal conditions (i.e. time = 180 min., pH = 4.5, adsorbent dose = 5 g L−1). The adsorption kinetics of malachite green molecules onto synthesized IPN was studied and compared using pseudo-first-order and pseudo-second-order models and we found that the adsorption process is better represented by the pseudo-second-order model. The different adsorption isotherm models like Langmuir, Freundlich, Dubinin–Radushkevich, Temkin, Redlich–Peterson and Sips isotherms were studied. The best-fitting isotherm model for the present experiment is the Langmuir model.

Central Composite Design Model to Study Swelling of GrA-cl-poly(AAm) hydrogel and Kinetic Investigation of Colloidal Suspension

Abstract: In the present study, the flocculation behavior of crosslinked copolymer GrA-cl-poly(AAm) hydrogel has been studied for the removal of turbidity from waste water. Sodium borohydride has been used for the reduction of the Gum rosin acids by which it gets converted into rosin alcohols. The reduced Gum rosin alcohol was crosslinked by the use of MBA and copolymerized with acrylamide using KPS as a redox initiator. Synthesized sample was then optimized for reaction conditions like reaction time, reaction temperature and the amount of solvent, monomer concentration, initiator concentration and pH of the reaction medium in order to get maximum percentage swelling. Synthesized samples were characterized using Fourier transform infrared spectroscopy, scanning electron of microscopy and X-ray diffraction techniques. Response surface methodology (RSM) based central composite design was used to study the effect of pH of swelling medium and temperature to maximize the percentage swelling. A statistical model (ANOVA) predicted pH 7.0 and temperature 40 °C as optimum operating conditions in order to get maximu swelling. GrA-cl-poly(AAm) hydrogel was found to be pH and temperature sensitive. Kaolin has been employed as a coagulant. The flocculation efficiency of the synthesized polymer was studied as a function of polymer dose, temperature and pH of the solution. GrA-cl-poly(AAm) observed to show maximum flocculation efficiency (95%) with 70mgL−1 polymer dose in pH 5.0 at 30 °C. The adsorption capacity of malachite green dye removal (95%) was also studied with this synthesized polymer. The results validate that GrA-cl-poly(AAm) hydrogel has significant flocculation and dye removal properties and can be employed as an effective and low-cost material for removal of impurities from waste water.