@article { ISI:000260452200009, title = {[Ru(salen)(NO)] complex encapsulated in mesoporous SBA-16 as catalyst for hydrogenation of ketones}, journal = {Catalysis Communications}, volume = {10}, number = {1}, year = {2008}, month = {OCT}, pages = {45-48}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

SBA-16 mesoporous silica with cubic lm3m structure was synthesized using Pluronic F127 poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer (EO106PO70EO106) and it blends with Pluronic P123 triblock copolymer (EO20PO70EO20) as supramolecular templates. The resulting material was used for encapsulating [Ru(salen)(NO)] complex and used in the hydrogenation of ketones to the corresponding alcohols. The pore entrance size of SBA-16 was precisely tailored by silylation with diphenyldichlorosilane to trap [Ru(salen)(NO)] complex in the cage of SBA-16. Small angle XRD, N-2 sorption measurements, UV-Vis and FT-IR analysis evidences the structural integrity of mesoporous silica as well as the complex. (C) 2008 Elsevier B.V. All rights reserved.

}, keywords = {Encapsulation, Hydrogenation, Ketones, SBA-16, [Ru(salen)(NO)] complex}, issn = {1566-7367}, doi = {10.1016/j.catcom.2008.07.029}, author = {Bordoloi, Ankur and Amrute, Amol P. and Halligudi, Shivaraj B.} } @article { ISI:000302893400028, title = {In situ encapsulation of ultra small ceria nanoparticles stable at high temperatures in the channels of mesoporous silica}, journal = {Microporous and Mesoporous Materials}, volume = {155}, year = {2012}, month = {JUN}, pages = {215-219}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Ultra small ceria nanoparticles of sizes \<2 nm stable at 500 degrees C are encapsulated in the channels of mesoporous silica by employing a novel method of synthesis. The method involves modifying non-ionic polymer templates with ionic surfactants to enhance anchoring of metal ion precursors. In this way, further silica wall formation around the template ensures isolation of the nanoparticles exclusively within the channels after template removal by heat treatment. Further understanding of the interaction of the composite template system and cerium precursor is gained by cyclic voltammetric studies. (C) 2012 Elsevier Inc. All rights reserved.

}, keywords = {ceria, Encapsulation, Mesoporous silica, Template synthesis}, issn = {1387-1811}, doi = {10.1016/j.micromeso.2012.02.006}, author = {Ghosh, Sumona and Jijil, Chamundi P. and Devi, R. Nandini} } @article { ISI:000320929200041, title = {Pd ultra-small clusters as precursors for silica-encapsulated Pd nanoreactors: highly sinter-resistant catalysts}, journal = {Chemcatchem}, volume = {5}, number = {7}, year = {2013}, month = {JUL}, pages = {1911-1916}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Sintering and consequent deactivation in supported metal catalysts is a severe problem encountered in heterogeneous catalysis. This problem can be addressed by encapsulating active metal nanoparticles within inert oxides such as silica, provided the oxide shell is porous to enable access of reactant molecules to the nanoparticle surface to facilitate catalysis. We report the synthesis of highly sinter-resistant silica-encapsulated Pd catalysts with nanoparticle sizes stabilized at (3.4 +/- 0.6)nm at high temperatures of approximately 750 degrees C. The synthesis was achieved by utilizing thiol-protected ultra-small clusters of Pd as precursors for silica encapsulation. The ultra-small clusters were synthesized by using propyl ammonium functionalised thiols making them water-dispersible and amenable for silica encapsulation. Abundance of organics also aided in creating porosity subsequent to calcination at high temperatures.

}, keywords = {cluster compounds, Encapsulation, nanoreactors, Palladium, silicates}, issn = {1867-3880}, doi = {10.1002/cctc.201200908}, author = {Samanta, Anupam and Devi, R. Nandini} } @article { ISI:000354137000018, title = {Encapsulation of ultra small metal clusters in silica: evolution of the concept of nanoreactors and the case of Ag-Pd@SiO2 alloy catalyst}, journal = {Catalysis Today}, volume = {251}, year = {2015}, note = {7th Tokyo Conference on Advanced Catalytic Science and Technology (TOCAT), Kyoto, JAPAN, JUN 01-06, 2014}, month = {AUG}, pages = {114-120}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The concept of encapsulation of ultra small clusters within silica evolved as a means to address the sintering of active metal nanoparticles and subsequent deactivation observed in supported noble metal catalysts. It is hypothesised that sintering, which mainly occurs due to mobility of metal species on the support surfaces, can be minimised if the growth and movement of metal nanoparticles are constrained. First, nanoparticles are isolated inside 1D channels in 2D mesoporous compounds and the idea develops to complete encapsulation of thiol protected ultra small nanoclusters in silica spheres. Sintering is better controlled in the latter due to the confined space for growth of nanoparticles. Access of reactant molecules to the active metal surfaces also is ensured by porosity created in the silica matrix forming the basis of the concept of nanoreactors. In this paper, we elaborate on the evolution of this concept from our earlier work on highly sinter resistant silica encapsulated Au, Pd and Au-Pd alloys to the present system of Ag-Pd alloy encapsulated in silica. Silver, with the lowest Tammann temperature among noble metals, is highly prone to sintering which is adequately controlled by alloying with Pd as well as encapsulation in silica. Its enhanced activity in paranitrophenol reduction in comparison with pure metals indicates the advantageous effect of alloying. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Ag-Pd alloy, Encapsulation, Sinter resistant, Sintering, Ultra small nanoclusters}, issn = {0920-5861}, doi = {10.1016/j.cattod.2014.11.006}, author = {Mondal, Sourik and Samanta, Anupam and Dhar, Basab B. and Devi, R. Nandini} } @article { ISI:000382587400004, title = {Encapsulation of yeast (Saccharomyces cereviciae) by spray drying for extension of shelf life}, journal = {Drying Technology}, volume = {34}, number = {11}, year = {2016}, month = {JAN}, pages = {1307-1318}, publisher = {TAYLOR \& FRANCIS INC}, address = {530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA}, abstract = {

The objective of the present work was to encapsulate yeast using different carrier materials and examine their efficacy in retaining viability of cells after spray drying. Slurry containing yeast cells along with known amount of carrier material (maltodextrin, corn starch, gum arabic, acacia gum, polyethylene glycol 8000, -cyclodextrin, and skimmed milk powder, one at a time) was added and served as feed. Among these carrier materials attempted, corn starch and maltodextrin showed the best results with respect to powder yield (59\%, w/w) and cell survival (80.5\%), respectively. However, considering both survival and powder yield (67 and 59\% w/w, respectively), corn starch was observed to be the most suitable carrier material.

}, keywords = {Cell viability, Encapsulation, freeze-drying, spray drying, Yeast}, issn = {0737-3937}, doi = {10.1080/07373937.2015.1112808}, author = {Chandralekha, A. and Tavanandi, A. Hrishikesh and Amrutha, N. and Hebbar, H. Umesh and Raghavarao, K. S. M. S. and Gadre, Ramchandra V.} } @article { ISI:000382349600001, title = {Large trisoctahedral Au nanoparticles encapsulated inside porous silica catalyses CO oxidation at room temperature: probing the effect of encapsulation and the role of step atoms and interfaces}, journal = {Applied Catalysis A-General}, volume = {524}, year = {2016}, month = {AUG}, pages = {1-7}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

As envisaged, a synthesis strategy is reported for encapsulating high index faceted trisoctahedral Au nanoparticles inside porous silica to preserve nanoparticle size by preventing sintering. Further, to probe the role of interfaces an active metal oxide junction was created by decorating trisoctahedral (TOH) Au nanoparticle with nano oxides before silica encapsulation. The activity of these catalysts was tested for CO oxidation reaction. The reaction was found to be facile on these encapsulated large structured Au nanoparticles showing appreciable activity at room temperature compared to non encapsulated counterparts. Apart from preventing sintering, the improved activity is demonstrated due to the retention of morphology and thereby the active centres due to encapsulation. (C) 2016 Elsevier B.V. All rights reserved.

}, keywords = {Defect sites, Encapsulation, High index facets, Metal-oxide active perimeter, Trisoctahedral Au nanoparticles}, issn = {0926-860X}, doi = {10.1016/j.apcata.2016.05.023}, author = {Sreedhala, S. and Maheshwari, Shruti and Betsy, K. J. and Vinod, C. P.} } @article {45579, title = {Nonconventional method for drying of Pseudomonas aeruginosa and its comparison with conventional methods}, journal = {Drying Technology}, volume = {37}, year = {2018}, month = {MAY}, pages = {839-853}, type = {Article}, abstract = {

In this study, preparation of dried cultures of Pseudomonas aeruginosa using nonconventional drying method, namely, low-temperature low-humidity (LTLH) drying was investigated. The effect of carrier materials (whey protein, corn starch, and trehalose) was examined one at a time and also in combinations (to explore the synergistic effect). The results were compared with those obtained using spray drying and freeze drying in terms of cell survival and dry cell powder yield. The powder samples were analyzed also for morphology, flowability, particle size, and moisture content. In LTLH drying, good cell survival was observed along with high powder yield when compared with that in spray drying. Corn starch showed the highest cell survival (91\%) and powder yield (94\%, w/w) among the carrier materials employed besides resulting in good cell survival (65\%) even after a storage period of 6 months.

}, keywords = {cell survival, Encapsulation, freeze drying, Low-temperature low-humidity (LTLH) drying, Pseudomonas aeruginosa, spray drying}, issn = {0737-3937}, doi = {10.1080/07373937.2018.1469140}, author = {Umashankar, K., and Chandralekha, A. and Dandavate, T., and Tavanandi, H. A. and Raghavarao, K. S. M. S.} } @article {48940, title = {Potential utility of bacterial protein nanoreactor for sustainable in-situ biocatalysis in wide range of bioprocess conditions}, journal = {Enzyme and microbial technology }, volume = {173}, year = {2024}, month = {FEB}, pages = {110354}, type = {Article}, abstract = {

Bacterial microcompartments (MCPs) are proteinaceous organelles that natively encapsulates the enzymes, substrates, and cofactors within a protein shell. They optimize the reaction rates by enriching the substrate in the vicinity of enzymes to increase the yields of the product and mitigate the outward diffusion of the toxic or volatile intermediates. The shell protein subunits of MCP shell are selectively permeable and have specialized pores for the selective inward diffusion of substrates and products release. Given their attributes, MCPs have been recently explored as potential candidates as subcellular nano-bioreactor for the enhanced production of indus-trially important molecules by exercising pathway encapsulation. In the current study, MCPs have been shown to sustain enzyme activity for extended periods, emphasizing their durability against a range of physical challenges such as temperature, pH and organic solvents. The significance of an intact shell in conferring maximum pro-tection is highlighted by analyzing the differences in enzyme activities inside the intact and broken shell. Moreover, a minimal synthetic shell was designed with recruitment of a heterologous enzyme cargo to demonstrate the improved durability of the enzyme. The encapsulated enzyme was shown to be more stable than its free counterpart under the aforementioned conditions. Bacterial MCP-mediated encapsulation can serve as a potential strategy to shield the enzymes used under extreme conditions by maintaining the internal microen-vironment and enhancing their cycle life, thereby opening new means for stabilizing, and reutilizing the enzymes in several bioprocess industries.

}, keywords = {Bioprocess industries, Encapsulation, Enzyme recycling, Enzyme Stability, Microcompartment, Nanobioreactor}, issn = {0141-0229}, doi = {10.1016/j.enzmictec.2023.110354}, author = {Shinde, Yashodhara D. and Chowdhury, Chiranjit} }