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Abhijit Bandyopadhyay

Bio: Abhijit Bandyopadhyay is an academic researcher from University of Calcutta. The author has contributed to research in topics: Natural rubber & Vinyl alcohol. The author has an hindex of 24, co-authored 116 publications receiving 1690 citations. Previous affiliations of Abhijit Bandyopadhyay include Indian Institute of Technology Kharagpur.


Papers
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Journal ArticleDOI
25 Apr 2005-Polymer
TL;DR: In this article, the organic-inorganic hybrid nanocomposites comprising poly(iminohexamethyleneiminoadipoyl), better known as Polyamide-6,6 (abbreviated henceforth as PA66), and silica (SiO2) were synthesized through sol-gel technique at ambient temperature.

122 citations

Journal ArticleDOI
TL;DR: In this paper, an organic-inorganic hybrid composites comprising acrylic rubber and silica were synthesized through sol-gel technique at ambient temperature, and the morphology of the hybrid materials was investigated by using the transmission electron microscope (TEM) and scanning electron microscopy (SEM).
Abstract: The organic-inorganic hybrid composites comprising acrylic rubber and silica were synthesized through sol-gel technique at ambient temperature. The composites were generated through the acid-catalyzed hydrolysis and subsequent condensations of inorganic tetraethoxysilane (TEOS) in the organic acrylic rubber (ACM), solvated in tetrahydrofuran. The morphology of the hybrid materials was investigated by using the transmission electron microscope (TEM) and scanning electron microscope (SEM). Transmission electron micrographs revealed that the silica particles, uniformly distributed over the rubber matrix, are of nanometer scale (20-90 nm). The scanning electron micrographs demonstrated the existence of silica frameworks dispersed in the rubber matrix of the hybrid composites. The X-ray silicon mapping also supported that observation. There was no evidence of chemical interaction between the rubber phase and the dispersed inorganic phase, as confirmed from the infrared spectroscopic analysis and solubility measurements. Dynamic mechanical analysis indicated mechanical reinforcements within the hybrid composites. The composites containing in situ silica, formed by sol-gel technique, demonstrated superior tensile strengths and tensile modulus values at 300% elongations with increasing proportions of tetraethoxysilane. However, the improvements in physical properties with similar proportions of precipitated silica were not significant. Maximum tensile strength and tensile modulus were obtained when the rubber phase in the hybrid composites was cured with ammonium benzoate and hexamethylenediamine carbamate system, as compared with benzoyl peroxide cured system. Thermal stability of the hybrid composites was not improved appreciably with respect to the virgin rubber specimen. Residue analysis from thermogravimetric study together with infrared spectroscopic analysis indicated the presence of unhydrolyzed tetraethoxysilane in the hybrid composites.

101 citations

Journal ArticleDOI
TL;DR: In this paper, a polyvinyl alcohol/silica organic inorganic hybrid composites were prepared by using sol-gel technique and the results were further supported by significant improvements in the Young's modulus and the tensile strengths of the samples.
Abstract: Poly(vinyl alcohol)/silica organic inorganic hybrid composites were prepared by using sol-gel technique. Tetraethoxysilane was used as the precursor for silica. The reaction was carried out in an aqueous medium having a pH of 1.5 with concentrated hydrochloric acid, used as the catalyst. All the composites were optically clear. Interaction at organic-inorganic interfaces due to hydrogen bonds was speculated from infrared spectroscopic analysis of the hybrid composites. Transmission electron microscopic studies revealed the existence of silica nanoparticles, uniformly dispersed in the organic matrix, which were found to grow in size with increase in tetraethoxysilane loading in the composites. Uniform dispersion of silica particles within the hybrid nanocomposites was also supported from the energy dispersive X-ray mapping of silicon. Dynamic mechanical properties exhibited substantial mechanical reinforcements due to the dispersion of nanosilica particles in the matrix. The results were further supported by significant improvements in the Young's modulus and the tensile strengths of the samples. All the hybrid composites demonstrated excellent water resistance.

90 citations

Journal ArticleDOI
TL;DR: Novel carboxymethyl guar gum-chemically modified multiwalled carbon nanotube (MCNT) hybrid hydrogels were synthesized at different MCNT levels as potential device for sustained trans-dermal release of diclofenac sodium to show relatively strong CMG-MCNT interaction.

78 citations

Journal ArticleDOI
TL;DR: In this article, the photo degradation of polystyrene (PS) by using zinc oxide (ZnO) as photo catalyst is reported, where the concentration of ZnO followed by the dispersion within the PS matrix has been found to be the key as the maximum weight loss of ∼ 16% in 2 h has been obtained with 0·5 wt-% of ZNO.
Abstract: This paper reports the photo degradation of polystyrene (PS) by using zinc oxide (ZnO) as photo catalyst. Virgin PS is not responsive to degradation by ultra violet (UV) light because of the presence of phenyl rings in its repeating units. ZnO acts as an UV absorber and helps in transferring the absorbed energy to various bonds of PS and causes degradation. The concentration of ZnO followed by the dispersion within the PS matrix has been found to be the key as the maximum weight loss of ∼ 16% in 2 h has been obtained with 0·5 wt-% of ZnO. Below and above this concentration, the degradation is clearly low. Addition of a UV sensitive dye has further improved this degradation (up to 18%) owing to synergism with ZnO. The degradation of PS has been further highlighted from infrared spectroscopy, surface analysis, viscosity average molecular weight studies and mechanical properties analysis. A suitable mechanism supporting the UV degradation has also been proposed.

75 citations


Cited by
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Journal ArticleDOI
TL;DR: Characterization and Properties 3928 8.2.1.
Abstract: 5. In Situ Polymerization 3907 5.1. General Polymerization 3907 5.2. Photopolymerization 3910 5.3. Surface-Initiated Polymerization 3912 5.4. Other Methods 3913 6. Colloidal Nanocomposites 3913 6.1. Sol-Gel Process 3914 6.2. In Situ Polymerization 3916 6.2.1. Emulsion Polymerization 3917 6.2.2. Emulsifier-Free Emulsion Polymerization 3919 6.2.3. Miniemulsion Polymerization 3920 6.2.4. Dispersion Polymerization 3921 6.2.5. Other Polymerization Methods 3923 6.2.6. Conducting Nanocomposites 3924 6.3. Self Assembly 3926 7. Other Preparative Methods 3926 8. Characterization and Properties 3928 8.1. Chemical Structure 3928 8.2. Microstructure and Morphology 3929 8.3. Mechanical Properties 3933 8.3.1. Tensile, Impact, and Flexural Properties 3933 8.3.2. Hardness 3936 8.3.3. Fracture Toughness 3937 8.3.4. Friction and Wear Properties 3937 8.4. Thermal Properties 3938 8.5. Flame-Retardant Properties 3941 8.6. Optical Properties 3942 8.7. Gas Transport Properties 3943 8.8. Rheological Properties 3945 8.9. Electrical Properties 3945 8.10. Other Characterization Techniques 3946 9. Applications 3947 9.1. Coatings 3947 9.2. Proton Exchange Membranes 3948 9.3. Pervaporation Membranes 3948 9.4. Encapsulation of Organic Light-Emitting Devices 3948

1,915 citations

Journal ArticleDOI
TL;DR: In this paper, the surface of inorganic nanoparticles is modified to improve the interfacial interactions between the inorganic particles and the polymer matrix, which improves the properties of polymeric composites.

1,709 citations

Journal ArticleDOI
TL;DR: In this article, the authors focus on graphite and describe its various modifications for use as modified fillers in polymer matrices for creating polymer-carbon nanocomposites, which is the basic building block of graphite.

1,092 citations

Journal ArticleDOI
TL;DR: Graphene-based materials and their composites possess promising applications in wide range of fields such as, electronics, biomedical aids, membranes, flexible wearable sensors and actuators as mentioned in this paper.
Abstract: Recent years have perceived many innovations in research and advancement of graphene, the thinnest two-dimensional atomic material. Graphene-based materials and their composites possess promising applications in wide range of fields such as, electronics, biomedical aids, membranes, flexible wearable sensors and actuators. The latest studies and progression in this subject area often produce inconsistent or inconclusive results. This review article assesses and summarises published data so as to provide a critical and comprehensive overview of state of the art. Firstly, the distinct structural nature of the graphene materials available is elucidated, as well as different production techniques available thus far. The assessment then discusses the various composites focusing different sub-functional regimes such as mechanical and collective functional applications such as energy, electronics biomedical, membranes and sensors. The utilisation of graphene and its derivatives in the manufacture of nanocomposites with different polymer matrices has been reconnoitred. Finally, a conclusion and perspective are given to discussing the remaining challenges for graphene nanocomposites in functional science and engineering.

610 citations