@article { ISI:000279836400026, title = {Synthesis and characterization of polyurethane-grafted single-walled carbon nanotubes via click chemistry}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {10}, number = {9}, year = {2010}, month = {SEP}, pages = {5700-5707}, publisher = {AMER SCIENTIFIC PUBLISHERS}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

Polyurethane (PU)-grafted carbon nanotubes were synthesized by the coupling of alkyne moiety decorated single walled carbon nanotube (SWCNT) with azide moiety containing PU using Cu(I) catalyzed Huisgen [3 + 2] cycloaddition click chemistry. The azide moiety containing poly(E-caprolactone)diol was synthesized by ring-opening polymerization and further used for PU synthesis. Alkyne-functionalizion of SWCNT was completed by the reaction of p-aminophenyl propargyl ether with SWCNT using a solvent free diazotization procedure. Nuclear magnetic resonance, Fourier transform infrared, and Raman spectroscopic measurements confirmed the functionalization of SWCNT. Scanning electron microscopy and transmission electron microscopy images showed an excellent dispersion of SWCNTs, and specially debundling of SWCNTs could be observed due to polymer assisted dispersion. A quantitative grafting was successfully achieved even at high content of functional groups.

}, keywords = {Carbon nanotubes, Click chemistry, dispersion, polyurethane}, issn = {1533-4880}, doi = {10.1166/jnn.2010.2434}, author = {Rana, Sravendra and Cho, Jae Whan and Kumar, Indresh} } @article { ISI:000354505100017, title = {Activation by pretreatment of Ag-Au/Al2O3 bimetallic catalyst to improve low temperature HC-SCR of NOx for lean burn engine exhaust}, journal = {Applied Catalysis B-Environmental}, volume = {174}, year = {2015}, month = {SEP}, pages = {145-156}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Bimetallic Ag-Au/Al2O3 catalyst was synthesised by successive impregnation of 1\% Au and 1\% Ag on in-house prepared high surface area alumina (450 m(2)/g). The corresponding monometallic catalysts were also prepared by loading 1\% Ag or 1\% Au on the same high surface area alumina for comparison. The catalysts were characterised by various physico-chemical techniques and tested for SCR activity under lean burn engine exhaust conditions. Ag-Au/Al2O3 catalyst prepared by successive impregnation method showed considerably higher NO reduction (100\%) to N-2 compared to 1\% Au/Al2O3 (70\%) whereas the activity was comparable with that of 1\% Ag/Al2O3 (96\%). The effect of various pretreatments on SCR activity of Ag-Au/Al2O3 was studied and pretreatment at 250 degrees C in flow of hydrogen was found to give the best results with 100\% NO conversion to N-2 at 353 degrees C. Further ageing of the catalyst under reaction feed at 500 degrees C resulted in considerable increase in low temperature activity of bimetallic catalyst with similar to 40\% NO conversion at 222 degrees C. Even though the SCR activity of pretreated Ag-Au/Al2O3 and Ag/Al2O3 were comparable, after ageing the Ag-Au/Al2O3 showed significantly higher NO conversion (95\%) compared to Ag/Al2O3 (83\%) and Au/Al2O3 (70\%). The formation of H-2 and CO due to steam reforming of higher hydrocarbon (decane) was evidenced at the temperature of highest deNO(x) activity. Detailed investigation of the textural properties of the pretreated and aged catalysts showed presence of well dispersed metallic Au and Ag-n(delta+) clusters after pretreatment in hydrogen at 250 degrees C. (C) 2015 Elsevier B.V. All rights reserved.

}, keywords = {Ag-Au bimetallic catalyst, Catalyst ageing, dispersion, Low temperature HC-SCR, Steam reforming}, issn = {0926-3373}, doi = {10.1016/j.apcatb.2015.02.035}, author = {More, Pavan M. and Nguyen, Duy L. and Granger, Pascal and Dujardin, Christophe and Dongare, Mohan K. and Shubhangi B. Umbarkar} } @article { ISI:000363775800020, title = {Effect of interfacial mass transfer on the dispersion in segmented flow in straight capillaries}, journal = {AICHE Journal}, volume = {61}, number = {12}, year = {2015}, month = {DEC}, pages = {4294-4308}, publisher = {WILEY-BLACKWELL}, address = {111 RIVER ST, HOBOKEN 07030-5774, NJ USA}, abstract = {

The effect of interfacial mass transfer on the extent of dispersion in liquid-liquid segmented flow in straight capillaries is studied. In the absence of interfacial mass transfer, dispersion coefficient was seen to go through a minimum with increasing flow rates. In the presence of mass transfer, physicochemical properties of both the phases and slug lengths were seen to vary along the capillary length. The extent of dispersion was always higher in the presence of interfacial mass transfer. The predictions using axial dispersion model deviated noticeably for larger capillaries as the model does not account for varying buoyancy, dynamic contacting, and Marangoni convection. Simulations of a first-order interfacial reaction considering varying slug lengths showed a significant change in optimum operating parameters than the conventional approach. A special case of drop-on-demand type of controlled two-phase flow in capillaries was also studied. (c) 2015 American Institute of Chemical Engineers.

}, keywords = {capillary, dispersion, interfacial mass transfer, segmented flow, slugs}, issn = {0001-1541}, doi = {10.1002/aic.14945}, author = {Deshpande, Jaydeep B. and Kulkarni, Amol A.} }