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1.
The bulk copolymerization of styrene–acrylonitrile monomers using styrene‐N+–montmorillonite complex as a comonomer in the polymerization was studied. The X‐ray diffraction (XRD) analysis showed that part of the styrene‐N+–montmorillonite complex remained non‐dispersed (immiscible) and the copolymer was excluded from the interlayer of the immiscible part of the clay. The successive chemical extraction process revealed that a reasonable amount of the styrene–acrylonitrile copolymer was directly attached to the styrene‐N+–montmorillonite complex and enveloped the clay. Highly exfoliated clay lamella and nanospheres (3–5 nm) were observed by transmission electron microscopy (TEM). The montmorillonite clay assume two different morphologies, immiscible and exfoliated, on the basis of the XRD and TEM data. A simple method of calculation of the ratio of the exfoliated/immiscible amounts of the clay indicated that the amount of the styrene‐N+–montmorillonite complex exfoliated into separate lamella was 40 % (w/w) of the amount of the clay samples containing 2 % of the (styrene‐N+–montmorillonite complex) clay. This amount of exfoliated clay decreases with the increase of the concentration of the clay. The presence of the styrene‐N+–montmorillonite clay in the copolymerization reaction had a minor effect on both the copolymer composition and the molecular weight. Modification of the clay with the derivatized styrene monomer can achieve a nanocomposite using a percentage no more than 4 % (w/w) of complex in the copolymer. Copyright © 2004 Society of Chemical Industry 相似文献
2.
S. Vaidyanathan K. M. Kavadia L. P. Borkar S. P. Mahajan 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1985,35(2):121-128
With a view to evaluate the effects of hydraulic retention time and volatile solids loading rate on methane production using water hyacinth, experiments were conducted in a 160 dm3 capacity, well-mixed continuous digestion unit at ambient temperature. The optimal design of biogas plant using water hyacinth was elucidated, to provide a unit giving a maximum methane yield of 0.16 nm3 kg?1 volatile solids added, which was 60% greater than the conventional plant using cowdung. The calculations of optimal design factors were based on reactor size, hydraulic retention time and volatile solids loading rate; considerations were made of capital cost, running costs and operational revenue. 相似文献
3.
Kannapiran Nagarajan Muthusamy Athianna Meena Sher Singh 《Journal of Inorganic and Organometallic Polymers and Materials》2021,31(8):3441-3459
Journal of Inorganic and Organometallic Polymers and Materials - Different concentrations of ZnFe2O4 and manganese substituted ZnFe2O4 nanoparticles (10%, 20% and 30%) dispersed... 相似文献
4.
The aqueous polymerization of acrylamide initiated by potassium permanganate/β-hydroxybutyric acid has been studied volumetrically at 35 ± 0.01°C in an inert medium. The rate of polymerization shows nearly square root dependence on β-hydroxybutyric acid at low concentration (3.12 – 12.5 · 10?3 mol dm?3). The order with respect to potassium permanganate has been found to be 0.6 indicating thereby a bimolecular mode of termination. The polymerization rate has been varied linearly at low monomer concentrations i.e. from 2.5 –7.0 · 10?2 mol dm?3. The dependence of number average degree of polymerization on the initial rate of polymerization and temperature has been determined. The over-all activation energy has been found to be 51.66 kJ mol?1. A kinetic reaction scheme is proposed on the basis of experimental results. 相似文献
5.
For the all-ones lower triangular matrices, the upper and lower bounds on rigidity are known to match [P. Pudlak, Z. Vavrin, Computation of rigidity of order n2/r for one simple matrix, Comment Math. Univ. Carolin. 32 (2) (1991) 213-218]. In this short note, we apply these techniques to the all-ones extended lower triangular matrices, to obtain upper and lower bounds with a small gap between the two; we show that the rigidity is . 相似文献
6.
Mahajan VN 《Applied optics》1994,33(34):8121
Zernike circle polynomials, their numbering scheme, and relationship to balanced optical aberrations of systems with circular pupils are discussed. 相似文献
7.
Mahajan Nitish Chauhan Amita Kumar Harish Kaushal Sakshi Sangaiah Arun Kumar 《Mobile Networks and Applications》2022,27(4):1423-1443
Mobile Networks and Applications - In the era of Internet of Things (IoT) powered by 5G technologies, Automobile Industry is headed towards a revolution. In Intelligent Transport Systems (ITS),... 相似文献
8.
Jobina Rajkumari Himani Meena Muralitharan Gangatharan Siddhardha Busi 《IET nanobiotechnology / IET》2017,11(8):987
Pseudomonas aeruginosa is a notorious pathogen that causes biofilm aided infections in patients with cystic fibrosis and burn wounds, resulting in significant mortality in immunocompromised individuals. This study reports a novel one‐step biosynthesis of gold nanoparticles using phytocompound, hordenine (HD), as a reducing and capping agent. The synthesis of the anisotropic hordenine‐fabricated gold nanoparticles (HD‐AuNPs) with an average particle size of 136.87 nm was achieved within 12 h of incubation at room temperature. Both HD and HD‐AuNPs exhibited significant antibiofilm activity against P. aeruginosa PAO1, although greater biofilm inhibition was observed for the nanoparticles as compared to hordenine alone. In the microtitre plate assay and tube method, the nanoparticles significantly inhibited the biofilm formation by 73.69 and 78.41%, respectively. The exopolysaccharide production by the test pathogen was arrested by 68.46% on treatment with the nanoparticles. Further, the effect of HD and HD‐AuNPs on the biofilm architecture of P. aeruginosa was revealed by light and confocal laser‐scanning microscopy micrographs. The overall results of this study suggested the synergistic antibiofilm effect of AuNPs and HD for the treatment of chronic bacterial infections caused by biofilms forming pathogens.Inspec keywords: molecular biophysics, biochemistry, gold, nanoparticles, nanofabrication, microorganisms, organic compounds, particle size, nanobiotechnologyOther keywords: green synthesis, anisotropic gold nanoparticles, hordenine, antibiofilm efficacy, Pseudomonas aeruginosa, pathogen, cystic fibrosis, burn wounds, one‐step biosynthesis, phytocompound, reducing agent, capping agent, particle size, microtitre plate assay, tube method, confocal laser‐scanning microscopy micrographs, Au 相似文献
9.
Rashmi Mahajan Akhshay Singh Bhadwal Nishant Kumar Mukil Madhusudanan Ramesh Namdeo Pudake Ravi Mani Tripathi 《IET nanobiotechnology / IET》2017,11(4):360
The present study reports a novel, facile, biosynthesis route for the synthesis of carbon nanodots (CDs) with an approximate quantum yield of 38.5%, using Musk melon extract as a naturally derived‐precursor material. The synthesis of CDs was established by using ultraviolet–visible (UV–vis) spectroscopy, Dynamic light scattering, photoluminescence spectroscopy, X‐ray diffraction, transmission electron microscopy and Fourier transform infrared (FTIR) spectroscopy. The as‐prepared CDs possess an eminent fluorescence under UV–light (λ ex = 365 nm). The size range of CDs was found to be in the range of 5–10 nm. The authors further explored the use of such biosynthesised CDs as a photocatalyst material for removal of industrial dye. Degradation of methylene blue dye was performed in a photocatalytic reactor and monitored using UV–vis spectroscopy. The CDs show excellent dye degradation capability of 37.08% in 60 min and reaction rate of 0.0032 min−1. This study shows that synthesised CDs are highly stable in nature, and possess potential application in wastewater treatment.Inspec keywords: carbon, nanostructured materials, nanofabrication, catalysis, photochemistry, ultraviolet spectra, visible spectra, photoluminescence, X‐ray diffraction, transmission electron microscopy, Fourier transform infrared spectra, fluorescence, dyesOther keywords: green synthesis, highly stable CD, photocatalytic performance, biosynthesis route, carbon nanodots, quantum yield, Musk melon extract, naturally derived‐precursor material, ultraviolet‐visible spectroscopy, dynamic light scattering, photoluminescence spectroscopy, X‐ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, FTIR spectroscopy, fluorescence, biosynthesised CD, photocatalyst material, industrial dye, methylene blue dye degradation, photocatalytic reactor, UV‐vis spectroscopy, wastewater treatment, size 5 nm to 10 nm, time 60 min 相似文献
10.
Ritika Puri Mohit Mahajan Nikhil Shri Sahajpal Harjeet Singh Harmanpreet Singh 《Drug development and industrial pharmacy》2016,42(7):1032-1041
Context: Docosahexanoic acid (DHA) is an essential omega-3 fatty acid for normal brain development and its use has increased considerably in recent years.Objective: The aim of this study is to develop and evaluate self-nanoemulsifying drug delivery systems (SNEDDS) of DHA for improved palatability, dispersibility and bioavailability.Methods: The SNEDDS were prepared and evaluated for miscibility, employing different combinations of olive oil and soyabean oil as oil phase, Span 80, Span 20, soya phosphatidylcholine, Labrafil M 1944 CS as surfactants while Tween 80, PEG 400, Cremophor RH40 and propylene glycol as cosurfactants. Thermodynamically stable SNEDDS were characterized for dispersibility, self-emulsification time, droplet size, zeta potential along with sensory analysis. The optimized formulation was subjected to ex vivo and in vivo evaluation such as intestinal permeability, memory performance test, brain concentration and histopathology studies.Results: The optimized SNEDDS formulation showed emulsification time of 27?±?4.7?s with droplet size of 17.6?±?3.5?nm and zeta potential of??37.6?±?0.5?mV. Intestinal absorption study depicted 18.3%, 21.5%, 41.5%, 98.7% absorption of DHA with SNEDDS-based formulation in comparison to 8.2%, 15.1%, 28.8%, 46.1% absorption of DHA with oil-based marketed formulation after 0.5, 1, 2 and 4?h. DHA concentration in brain homogenate was found to be increased to 2.6-fold in comparison to DHA-marketed formulation. This could be ascribed to enhanced dispersibility and bioavailability of DHA from nanosized formulation.Conclusion: The developed formulation led to enhanced dispersibility and bioavailability of DHA due to the formation of nanodroplets. 相似文献