Jitendra Naik

Removal of Brilliant Green from wastewater using conventional and ultrasonically prepared poly(acrylic acid) hydrogel loaded with kaolin clay: A comparative study

The present work deals with the removal of Brilliant Green dye from wastewater using a poly(acrylic acid) hydrogel composite (PAA-K hydrogel) prepared by incorporation of kaoline clay. The composite has been synthesized using ultrasound assisted polymerization process as well as the conventional process, with an objective of showing the better effectiveness of ultrasound assisted synthesis. It has been observed that the hydrogel prepared by ultrasound assisted polymerization process showed better results. The optimum conditions for the removal of dye are pH of 7, temperature of 35°C, initial dye concentration of 30mg/L and hydrogel loading of 1g. The extent of removal of dye increased with an increase in the contact time and initial dye concentration. A pseudo-second-order kinetic model has been developed to explain the adsorption kinetics of dye on the PAA-K hydrogel. Thermodynamic and kinetic parameters indicate that the adsorption process is spontaneous in nature and the PAA-K hydrogel prepared by ultrasound process is a promising adsorbent compared to conventional process. The obtained adsorption data has also been fitted into commonly used adsorption isotherms and it has been found that Freundlich as well as Langmuir adsorption isotherm models fits well to the experimental results.

Effect of Treatment of Maleic Anhydride on Mechanical Properties of Natural Fiber: Polystyrene Composites

Abstract: In the present work, banana, hemp, and sisal fibers are employed as fillers for the formation of natural fiber:polystyrene composites in the ratios of 55:45, 50:50, 45:55, and 40:60 (wt/wt). The natural fibers were treated with maleic anhydride. The Youngs modulus, flexural modulus, impact strength, and Shore-D hardness all decreased with increasing amounts of fibers in the natural fiber:polystyrene composites. The sisal fiber composites show the highest mechanical strength for all ratios. A maleic anhydride treatment shows significant improvement in Youngs modulus, flexural modulus, impact strength, and Shore-D hardness compared with the untreated fiber composites.

Aceclofenac microspheres: Quality by design approach

The purpose of this study was to prepare polymeric microspheres containing aceclofenac by single emulsion [oil-in-water (o/w)] solvent evaporation method. Two biocompatible polymers, ethylcellulose, and Eudragit® RS100 were used in combination. Seven processing factors were investigated by Plackett-Burman design (PBD) in order to enhance the encapsulation efficiency of the microspheres. A Plackett-Burman design was employed by using the Design-Expert® software (Version-8.0.7.1). The resultant microspheres were characterized for their size, morphology, encapsulation efficiency, and drug release. Imaging of particles was performed by field emission scanning electron microscopy. Interaction between the drug and polymers were investigated by Fourier transform infrared (FTIR) spectroscopy, and X-ray powder diffractometry (XRPD). Graphical and mathematical analyses of the design showed that Eudragit® RS100, and polyvinyl alcohol (PVA) were significant negative effect on the encapsulation efficiency and identified as the significant factor determining the encapsulation efficiency of the microspheres. The low magnitudes of error and the significant values of R(2) in the present investigation prove the high prognostic ability of the design. The microspheres showed high encapsulation efficiency (70.15% to 83.82%). The microspheres were found to be discrete, oval with smooth surface. The FTIR analysis confirmed the compatibility of aceclofenac with the polymers. The XRPD revealed the dispersion of drug within microspheres formulation. Perfect prolonged drug release profile over 12h was achieved by a combination of ethylcellulose, and Eudragit® RS100 polymers. In conclusion, polymeric microspheres containing aceclofenac can be successfully prepared using the technique of experimental design, and these results helped in finding the optimum formulation variables for encapsulation efficiency of microspheres.

Esterification Effect of Maleic Anhydride on Surface and Volume Resistivity of Natural Fiber/Polystyrene Composites

The natural fibers (banana, hemp and sisal) and polystyrene (PS) were taken for the preparation of natural fiber polymer composites in the different ratios of 40:60, 45:55, 50:50 and 55:45 (wt/wt), respectively. These fibers were esterified with maleic anhydride (MA) and the effect of esterification of maleic anhydride was studied on surface resistivity and volume resistivity of natural fiber/polystyrene composites. It was found that the untreated fibers composites show more surface resistivity and volume resistivity in comparison to maleic anhydride treated fibers composites. An untreated hemp fibers composite shows maximum surface and volume resistivity while maleic anhydride treated sisal fibers composites show minimum surface and volume resistivity.

The Compatibilizing Effect of Maleic Anhydride on Swelling Properties of Plant-Fiber-Reinforced Polystyrene Composites

In this work the fibers of banana, hemp, and sisal are employed as fillers for the formation of wood polymer composites with polystyrene in the different ratios of 40:60 and 45:55 (wt/wt), respectively. These fibers were esterified with maleic anhydride, and the effect of maleic anhydride was studied on absorption of steam and water at ambient temperature in wood polymer composites. Untreated fiber composites show more absorption of steam in comparison to maleic anhydride (MA)–treated fiber composites. The absorption of water increases with the increase in time from 2–30 h in all untreated fiber composites. The maximum absorption of water was found in hemp fiber composites and the minimum in sisal fiber composites. The maleic anhydride esterified fiber composites showed less absorption of water than the untreated fiber composites. Steam absorption in MA treated and untreated fiber composites is higher than the water absorption in respective fiber composites. The wood polymer composites containing low amount of fiber shows less absorption of steam and water at ambient temperature than the composites containing a greater amount of fiber in respective fiber composites.

Mechanical Properties of Wood Polymer Composites Prepared from Agro-Waste and HDPE

Abstract: Wood polymer composites based on untreated and maleic anhydride treated banana, hemp, and sisal fibers with HDPE resin are prepared in different ratios of 55:45, 50:50, 45:55, and 40:60 (wt/wt), respectively. Youngs modulus and flexural modulus decrease with increase in fiber amount in the polymer. Maleic anhydride-treated fiber composites show highest Youngs modulus and flexural modulus. The impact strength and shore-D hardness is also observed to be higher in maleic anhydride-treated fiber composites than in the untreated fiber composites.

Studies on Electrical Properties of Natural Fiber: HDPE Composites

Abstract: The composites of banana, hemp, and agave with HDPE resin were separately prepared in different ratios, 60:40, 55:45, 50:50, and 45:55 (wt/wt). These fibers were also treated with maleic anhydride and the effect of maleic anhydride was studied on surface resistivity and volume resistivity of wood polymer composites. The surface resistivity decreases with an increase in fiber content in the composites, while volume resistivity increases. The maximum surface and volume resistivities were observed in untreated banana fiber composite, while minimum surface resistivity and volume resistivity were found in maleic anhydride-treated agave fiber composite. The decrement in volume resistivity and surface resistivity is due to the increment in cross-linking between polymer and fiber by treatment with maleic anhydride.

Solvent evaporation and spray drying technique for micro- and nanospheres/particles preparation: A review

ABSTRACT This article presents a comprehensive review of research relating to the preparation of biodegradable and biocompatible controlled/sustained release of micro and nanoparticles. It covers recent developments in the area of technology through solvent evaporation followed by lyophilization and spray drying. The last decade seen a shift from empirical formulation efforts to a technological approach based on better understanding of micro and nanoparticle formation in the solvent evaporation and spray drying technique. This review provides concepts and a theoretical framework for the preparation of micro and nanoparticle formation. Encapsulation of pharmaceutical materials has received much attention due to enhanced effectiveness, bioavailability, and the dissolution rates that can be achieved. Polymeric micro and nanoparticles can be used to transport drug in a rate-controlled and sometimes targeted manner. Initially, laboratory-scale experiments are performed, but for industrial scale-up, experiments are required using sophisticated technologies. The objective of this review article is to summarize the solvent evaporation and spray drying techniques for the preparation of biodegradable and biocompatible controlled/sustained release of micro and nanospheres/particles with focus on the steps involved in its preparation, materials used, and the technique of microencapsulation. The review also summarizes recent research on solvent evaporation and spray drying.

Effect of Polymer Concentration on Sustained Release Microparticles of Metformin Hydrochloride Prepared by Using Spray Dryer

Metformin hydrochloride, polyacrylic acid and β-cyclodextrin were taken for the preparation of spray dried sustained released micro particles in a different ratios. These sustained release micro particles were used for the preparation of tablets. Hardness of tablet increases with increase in concentration of polymer while the percentage friability decreases with increase in polymer concentration in tablet. The encapsulated drug shows better sustained release than the conventional tablet. The kinetics of the dissolution process were studied by analyzing the dissolution data using three kinetic equations—the zero-order equation, the first-order equation and the Hixson–Crowell cube root law equation.

Optimization of sustained release aceclofenac microspheres using response surface methodology

Polymeric microspheres containing aceclofenac were prepared by single emulsion (oil-in-water) solvent evaporation method using response surface methodology (RSM). Microspheres were prepared by changing formulation variables such as the amount of Eudragit® RS100 and the amount of polyvinyl alcohol (PVA) by statistical experimental design in order to enhance the encapsulation efficiency (E.E.) of the microspheres. The resultant microspheres were evaluated for their size, morphology, E.E., and in vitro drug release. The amount of Eudragit® RS100 and the amount of PVA were found to be significant factors respectively for determining the E.E. of the microspheres. A linear mathematical model equation fitted to the data was used to predict the E.E. in the optimal region. Optimized formulation of microspheres was prepared using optimal process variables setting in order to evaluate the optimization capability of the models generated according to IV-optimal design. The microspheres showed high E.E. (74.14±0.015% to 85.34±0.011%) and suitably sustained drug release (minimum; 40% to 60%; maximum) over a period of 12h. The optimized microspheres formulation showed E.E. of 84.87±0.005 with small error value (1.39). The low magnitudes of error and the significant value of R(2) in the present investigation prove the high prognostic ability of the design. The absence of interactions between drug and polymers was confirmed by Fourier transform infrared (FTIR) spectroscopy. Differential scanning calorimetry (DSC) and X-ray powder diffractometry (XRPD) revealed the dispersion of drug within microspheres formulation. The microspheres were found to be discrete, spherical with smooth surface. The results demonstrate that these microspheres could be promising delivery system to sustain the drug release and improve the E.E. thus prolong drug action and achieve the highest healing effect with minimal gastrointestinal side effects.