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531.
Intensification of esterification of acids for synthesis of biodiesel using acoustic and hydrodynamic cavitation 总被引:2,自引:0,他引:2
Cavitation results in conditions of turbulence and liquid circulation in the reactor which can aid in eliminating mass transfer resistances. The present work illustrates the use of cavitation for intensification of biodiesel synthesis (esterification) reaction, which is mass transfer limited reaction considering the immiscible nature of the reactants, i.e., fatty acids and alcohol. Esterification of fatty acid (FA) odour cut (C(8)-C(10)) with methanol in the presence of concentrated H(2)SO(4) as a catalyst has been studied in hydrodynamic cavitation reactor as well as in the sonochemical reactor. The different reaction operating parameters such as molar ratio of acid to alcohol, catalyst quantity have been optimized under acoustic as well as hydrodynamic cavitating conditions in addition to the optimization of the geometry of the orifice plate in the case of hydrodynamic cavitation reactors. Few experiments have also been carried out with other acid (lower and higher)/methanol combination viz. caprylic acid and capric acids with methanol with an aim of investigating the efficacy of cavitation for giving the desired yields and also to quantify the degree of process intensification that can be achieved using the same. It has been observed that ambient operating conditions of temperature and pressure and reaction times of <3h, for all the different combinations of acid (lower and higher)/methanol studied in the present work, was sufficient for giving >90% conversion (mol%). This clearly establishes the efficacy of cavitation as an excellent way to achieve process intensification of the biodiesel synthesis process. 相似文献
532.
Sarangi S. N. Adhikari P. K. Pandey D. Sahu S. N. 《Journal of nanoparticle research》2010,12(6):2277-2286
Journal of Nanoparticle Research - CdSe nanocrystalline thin films have been synthesized on indium tin oxide (ITO) substrates by an electrodeposition technique. A Schottky junction device in the... 相似文献
533.
Rajan Adhikari Dr. Jan Brox Stephen Massicot Dr. Michael Ruppel Prof. Dr. Norbert Jux Dr. Hubertus Marbach Prof. Dr. Hans-Peter Steinrück 《Chemphyschem》2023,24(17):e202300539
The front cover artwork is provided by the groups of Prof. Dr. Hans-Peter Steinrück and Prof. Dr. Norbert Jux at the Friedrich-Alexander-Universität (FAU) Erlangen-Nürnberg. The image shows a mixture of six 2H-tetrakis-(3, 5-di-tert-butyl-phenyl)(x)benzoporphyrins (2H-diTTBP(x)BPs, x = 0, 1, 2-cis, 2-trans, 3, or 4) molecules forming a porous square structure on Ag(111) as observed in scanning tunneling microscopy (STM) at room temperature. Read the full text of the Research Article at 10.1002/cphc.202300355 . 相似文献
534.
Mohammad Umer Lone Nihar Sahu Dr. Raj Kumar Roy Dr. Bimalendu Adhikari 《Chemistry (Weinheim an der Bergstrasse, Germany)》2023,29(1):e202202711
Proper monomer design is the key to enhancing the strength of noncovalent interactions between the molecules toward the efficient formation of supramolecular polymers (SPs). We have designed and synthesized 1,n′-disubstituted ferrocene-azobenzene-long alkyl chains, Fc(CONH-Azo-TDP)2, to afford SPs with a high probability. The design exploits the ‘‘molecular ball-bearing’’ property of the ferrocene core, which allows two azobenzene arms to rotate in the planes of cyclopentadienyl rings, generating the most suitable molecular conformation required for SP formation. This ferrocene monomer formed a supergel consisting of SPs supported by strong intermolecular (H-bonding and π-π stacking) interactions and higher enthalpy gain than the reference molecules, where the central ferrocene core was replaced by flexible aliphatic as well as rigid benzene linkers. The molecular conformation involved in SPs, the strength of noncovalent interactions, and the process of supramolecular polymerization were investigated through NMR, UV-Vis, XRD and TEM studies. The results demonstrate that ferrocene may act as a good modulator for constructing efficient SPs. 相似文献
535.
Using different microscopic techniques, we investigate the morphology and the micro-deformation processes in two entirely different classes of polymer based composites: natural biocomposites and synthetic polymer composites. The emphasis has been put on the comparison of the micromechanical properties of those composite materials. In the natural layered composites exemplified by human cortical bone, analogous to the synthetic glassy polymers, craze-like deformation zones were formed. A strong dependence of deformation mechanisms (such as transition from formation of single crazes to multiple crazing behaviour) on the layer dimension was observed in the layered composites made up of different amorphous polymers. 相似文献
536.
The correlation between the morphology and the deformation mechanism in styrene/butadiene block copolymers having modified architecture and in blends with homopolymer polystyrene (hPS) was studied. It was demonstrated that the morphology formation in the block copolymers is highly coupled with their molecular architecture. In particular, the micromechanical behaviour of a star block copolymer and its blends with polystyrene was investigated by using electron microscopy and tensile testing. A homogeneous plastic flow of polystyrene lamellae (thin layer yielding) was observed if the lamella thickness was in the range of 20 nm. The deformation micromechanism switched to the formation of craze-like deformation zones when the average PS lamella thickness changed to about 30 nm and more. 相似文献