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Modification of polyaniline (PANI) is significant to attain the required targeted applications in this modern era. Radiations are preferred to modify PANI because this protocol of modification does not involve any chemical agent that can... more
Modification of polyaniline (PANI) is significant to attain the required targeted applications in this modern era. Radiations are preferred to modify PANI because this protocol of modification does not involve any chemical agent that can introduce any impurity. In this chapter, modification of PANI via gamma irradiation, electron beam (EB) irradiation, and ion implantation technique is discussed in detail. The principles of all these techniques are also elaborated. The effect of gamma and EB irradiations on different properties including cross-linking, microstructure, mechanical and wear properties, degradation and oxidative behavior, stability and solubility of PANI are explained. In case of ion implantation technique, effects of ion implantation on concentration of radical of PANI, amount of nitrogen and hydrogen atom in PANI, electrical conductivity, stability, shrinkage effect, color change, oxidation–reduction effect, and degradation behavior of PANI are illustrated. It is foun...
One of the important applications of polyurethanes is polyurethane foam. Flexible type of polyurethane foam is divided into many types and one of them is visco-elastic foam. Visco-elastic foam is unique foam showing both viscous and... more
One of the important applications of polyurethanes is polyurethane foam. Flexible type of polyurethane foam is divided into many types and one of them is visco-elastic foam. Visco-elastic foam is unique foam showing both viscous and elastic behavior at same time. Visco-elastic foam covers major applications of flexible polyurethane foam. Visco-elastic foam samples were synthesized on lab scale by cup foaming. All samples were characterized by finding density of each sample. Cream time, gel time and rise time were also estimated for each sample. The chemical compositions of all polyurethane foam samples were characterized by FTIR analysis.
pH responsive hydrogels have gained much attraction in biomedical fields. We have formulated ternary hydrogel films as a new carrier of drug. Polyelectrolyte complex of chitosan/guar gum/polyvinyl pyrrolidone cross-linked via sodium... more
pH responsive hydrogels have gained much attraction in biomedical fields. We have formulated ternary hydrogel films as a new carrier of drug. Polyelectrolyte complex of chitosan/guar gum/polyvinyl pyrrolidone cross-linked via sodium tripolyphosphate was developed by solution casting method. Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis were conducted to examine the interactions between the polymeric chains, surface morphology and thermal stability, respectively. The swelling tests resulted that the swelling was reduced with the increase in the concentration of crosslinker due to the more entangled arrangement and less availability of pores in hydrogels. Ciprofloxacin hydrochloride was used as a model drug and its release in simulated gastric fluid, simulated intestinal fluid and phosphate buffer saline solution was studied. pH responsive behaviour of the hydrogels have subjected these hydrogels for drug release applications.
The chitosan/polyvinyl alcohol/halloysite nanoclay (CS/PVA/HNC) loaded with cephradine drug electrospun nanofibers (NFs) were fabricated and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy... more
The chitosan/polyvinyl alcohol/halloysite nanoclay (CS/PVA/HNC) loaded with cephradine drug electrospun nanofibers (NFs) were fabricated and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) techniques. FTIR analysis confirmed the hydrogen bonding between the polymer chain and the developed siloxane linkages. SEM analysis revealed the formation of uniform NFs having beads free and smooth surface with an average diameter in 50–200 nm range. The thermal stability of the NFs was increased by increasing the HNC concentration. The antimicrobial activity was examined against Escherichia  coli and staphylococcus strains and the NFs revealed auspicious antimicrobial potential. The drug release was studied at pH 7.4 (in PBS) at 37 °C. The drug release analysis showed that 90% of the drug was released from NFs in 2 h and 40 min. Hence, the prepared NFs could be used as a potential drug carrier and release in a...
The objective of this work is to fabricate hydrogel films which are biodegradable and also fit for packaging applications. The hydrogel films were prepared by the reaction of polyvinyl alcohol and gelatin with and without... more
The objective of this work is to fabricate hydrogel films which are biodegradable and also fit for packaging applications. The hydrogel films were prepared by the reaction of polyvinyl alcohol and gelatin with and without 3-aminopropyltriethoxysilane (APTEOS) cross-linker. The hydrogel films were then characterized by FTIR spectroscopy, degree of swelling, TGA, SEM analysis and mechanical testing. The FTIR spectra of the hydrogel films confirmed the presence of both polymers and hydrogen bonding between them. TGA analysis confirmed the increase in thermal stability with the increase of cross-linker amount. SEM analysis confirmed the increase in uniformity of structure with the increase of cross-linker amount. The increase in cross-linker amount resulted in decrease of degree of swelling and increase of tensile strength. The biodegradability of hydrogel films was evaluated by performing soil burial test and found to be decreased with the increase of cross-linker amount. In order to b...
Fresh and clean water is consistently depleting and becoming a serious problem with rapid increases in population, so seawater desalination technology has captured global attention. For an efficient desalination process, this work... more
Fresh and clean water is consistently depleting and becoming a serious problem with rapid increases in population, so seawater desalination technology has captured global attention. For an efficient desalination process, this work proposes a novel, nanofibrous, thin-film composite membrane (NF-TFC) based on the deposition of the nanofibrous active layer of a blend of chitosan (CS) and poly (vinylpyrrolidone) (PVP) crosslinked with maleic acid on a 3-triethoxysilylpropylamine functionalized cellulose acetate substrate. FTIR analysis demonstrated the development of chemical and physical interactions and confirmed the incorporation of functional groups present in the NF-TFC. Scanning electron microscopy (SEM) micrographs depict the fibrous structure of the active layers. The reverse osmosis (RO) desalination characteristics of NF-TFC membranes are elevated by increasing the concentration of the crosslinker in a CS/PVP blend. Cellulose acetate (CA)-S4 attained an optimal salt rejection ...
The extensive use of pesticides in agricultur has raised toxicity level in environment because of their mutagenic and carcinogenic activity. A sensitive technique is needed to develop for the detection of pesticides to get high... more
The extensive use of pesticides in agricultur has raised toxicity level in environment because of their mutagenic and carcinogenic activity. A sensitive technique is needed to develop for the detection of pesticides to get high sensitivity and selectivity in complex matrices. Modified Stober‘s method was used for the synthesis of pure SiO2 particles and grafted by linoleic acid. Grafted SiO2 were examined for its capability as a sorbent for removal and preconcentration of four organochlorine pesticides i.e. endrin, dieldrin, aldrin and DDT. The particles of SiO2 undergo hydrophobic interaction with linoleic acid by grafting. Both pure SiO2 and linoleic acid grafted SiO2 particles were characterized by SEM, FTIR and XRD. FTIR confirmed the grafting of SiO2 with linoleic acid. XRD and SEM results showed monodispersed and spherical SiO2 particles. The evaluation of grafted SiO2 was carried out by spiking organochlorine pesticides in drinking water. The grafted SiO2 particles could be u...
Pictorial diagram of multi-responsive hydrogels for controlled drug release system.
Silane crosslinked biopolymer based novel pH-responsive hydrogels were fabricated by blending the cationic (chitosan) and anionic (alginate) polymers with poly(vinyl alcohol). Tetraethoxysilane (TEOS) was used, as a crosslinker in... more
Silane crosslinked biopolymer based novel pH-responsive hydrogels were fabricated by blending the cationic (chitosan) and anionic (alginate) polymers with poly(vinyl alcohol). Tetraethoxysilane (TEOS) was used, as a crosslinker in different amounts due to its nonhazardous nature, to study its impact on physical and chemical properties of the prepared injectable hydrogels along with the controlled release of drug. The swelling response of the prepared hydrogels was examined in different solvent media which exhibited decreased swelling ratio with increase in the amount of TEOS. All the fabricated hydrogels represented highest swelling at acidic pH while low swelling at basic and neutral pH. This specific pH sensitive behavior at pH 7 made them an appropriate candidate for the injectable controlled drug delivery in which Neomycin Sulfate (NMS) was successfully loaded on suitable hydrogel (comprising 50μL TEOS) to study its release mechanism. The results revealed that in simulated gastric fluid (SGF), hydrogel released the entire drug (NMS) in initial 30min while in simulated intestinal fluid (SIF), NMS was released in a controlled way up to 83% in 80min. These results endorsed that the hydrogels could be practiced as a smart intelligent material for injectable controlled drug delivery as well as for other biomedical applications at physiological pH.
Novel silane crosslinked tough hydrogel scaffolds were prepared using chitosan (CS) and polyvinyl alcohol (PVA) to give network structure and scaffolds properties. The influence of crosslinking and PVA concentration on scaffolds were... more
Novel silane crosslinked tough hydrogel scaffolds were prepared using chitosan (CS) and polyvinyl alcohol (PVA) to give network structure and scaffolds properties. The influence of crosslinking and PVA concentration on scaffolds were studied. Fourier transform infrared spectroscopy (FTIR) spectroscopy confirmed the presence of incorporated components. Tensile strength (TS) and fracture strain analysis of scaffolds were detected owing to the mutual effect of chemically and physically crosslinked network. Tough hydrogel scaffolds having 90% CS and 10% PVA exhibited TS of 49.18MPa and 10.15% elongation at break. The contact angle is less than 90(°) exhibited the hydrophilic nature of the scaffold. X-ray diffraction analysis (XRD) indicated the characteristics peaks fitting to CS and PVA and increase in the crystallinity of scaffolds. Cytotoxicity of scaffolds with different human fibroblast cell lines (F121, F192 and F84) for indirect method and human dermal fibroblast cell lines (F121...
Graphene oxide (GO) was indigenously synthesized from graphite using standard Hummers method. Chitosan-graphene oxide green composite films were fabricated by mixing aqueous solution of chitosan and GO using dilute acetic acid as a... more
Graphene oxide (GO) was indigenously synthesized from graphite using standard Hummers method. Chitosan-graphene oxide green composite films were fabricated by mixing aqueous solution of chitosan and GO using dilute acetic acid as a solvent for chitosan. Chitosan of different viscosity and calculated molecular weight was used keeping amount of GO constant in each composite film. The structural properties, thermal stability and mechanical properties of the composite films were investigated using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and tensile test. FTIR studies revealed the successful synthesis of GO from graphite powder and it was confirmed that homogenous blending of chitosan and GO was promising due to oxygenated functional groups on the surface of GO. XRD indicated effective conversion of graphite to GO as its strong peak observed at 11.06° as compared to pristine graphite which appeared at 26°. Moreover, mechanical analysis confirmed the effect of molecular weight on the mechanical properties of chitosan-GO composites showing that higher molecular weight chitosan composite (GOCC-1000) showed best strength (higher than 3GPa) compared to other composite films. Thermal stability of GOCC-1000 was enhanced for which residual content increased up to 56% as compared to the thermal stability of GOCC-200 whose residue was restricted to only 24%. The morphological analysis of the composites sheets by SEM was smooth having dense structure and showed excellent interaction, miscibility, compatibility and dispersion of GO with chitosan. The prepared composite films find their applications as biomaterials in different biomedical fields.
Selected properties of chitosan (CS) and poly(vinyl alcohol) (PVA) blends crosslinked by tetraethoxysilane (TEOS) were studied. XRD analysis showed characteristics peak at 22.5° attributed to the crystalline structure of CS and PVA. DSC... more
Selected properties of chitosan (CS) and poly(vinyl alcohol) (PVA) blends crosslinked by tetraethoxysilane (TEOS) were studied. XRD analysis showed characteristics peak at 22.5° attributed to the crystalline structure of CS and PVA. DSC thermograms unveiled the quantitative determination of free, intermediate and bound water in the blends. Tensile strength and fracture strain of blends were observed due to the combined effect of physically and chemically crosslinked network structures. The decrease in water contact angle indorsed the hydrophilic performance while the storage modulus G' and loss modulus G″ was decreased as the temperature was increased exhibited the viscoelastic property of the blends. The fabricated blends can be employed for drug delivery systems, tissue engineering and other biomedical applications.
The feasibility of methods of trans-esterification reactions for the preparation of polyols from unsaturated soybean oil and castor oil have shown in this study. The polyol products formed from soybean oil has primary alcohol functional... more
The feasibility of methods of trans-esterification reactions for the preparation of polyols from unsaturated soybean oil and castor oil have shown in this study. The polyol products formed from soybean oil has primary alcohol functional group. For castor oil polyol, hydroxyl group of any chain of triglyceride is replaced by chlorine. Thus the polyol formed has two hydroxyl (-OH) groups. Polyol is identified from hydroxyl functional group using Fourier Transform Infrared Spectroscopy (FTIR), and characterized by acid value. It is seen that the synthesized polyols are useful in the treatment of processes, using polyols for the production of polyurethanes, and also manipulated to synthesize polyurethane with required properties.
ABSTRACT This study aims at fabrication of zinc oxide (ZnO) filled glass fiber reinforced polyester (GFRP) composites with varying concentrations of filler and investigation of their mechanical and thermal behavior. In this study, ZnO was... more
ABSTRACT This study aims at fabrication of zinc oxide (ZnO) filled glass fiber reinforced polyester (GFRP) composites with varying concentrations of filler and investigation of their mechanical and thermal behavior. In this study, ZnO was dispersed in polyester, and laminates were fabricated by hand lay-up technique followed by compression molding. Mechanical properties were determined by flexural strength analysis, impact strength and hardness testing whereas thermal stability by thermogravimetric analysis (TGA). Flexural strength of 3 wt.% ZnO filled GFRP composite was improved significantly (up to 62.12%) in comparison to unfilled composite. Hardness, impact strength and thermal stability have also been found increased gradually with increase in ZnO loading.