01313nas a2200157   4500008004100000022001400041245009400055210006900149260007300218300001200291490001100303520067200314100002100986700003001007856011801037       2012                        eng d  a0009-261400aEffect of digestive ripening agent on nanoparticle size in the digestive ripening process0 aEffect of digestive ripening agent on nanoparticle size in the d  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcFEB  a101-1040 v525-263 a<p>Digestive ripening is an efficient method that leads to monodispersed nanoparticles from polydispersed ones. A systematic investigation of digestive ripening with different agents viz. dodecanethiol and dodecylamine on different metallic systems is presented. It is shown that both the metallic system involved and the digestive ripening agent have influences on the final size distribution. Further, it is demonstrated that the interaction strength between the different metals and the digestive ripening agents based on Hard Soft Acid Base principles could be invoked to explain the variation in nanoparticle size. (C) 2012 Elsevier B.V. All rights reserved.</p>1 aSahu, Puspanjali1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/effect-digestive-ripening-agent-nanoparticle-size-digestive-ripening-process-001201nas a2200157   4500008004100000022001400041245012800055210006900183260011000252300001400362490000600376520048300382100002100865700003000886856012700916       2013                        eng d  a2040-336400aFine control of nanoparticle sizes and size distributions: temperature and ligand effects on the digestive ripening process0 aFine control of nanoparticle sizes and size distributions temper  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT  a1768-17710 v53 a<p>It is demonstrated that a fine control over the size and size distribution of nanoparticles could be achieved using digestive ripening at different temperatures. Such variations in size and size distributions hugely influence the self-assembled processes in nanoparticles, and result in superlattice structures that are controlled by subtle interplay between ligand orientational entropy and their interdigitation and the van der Waals attraction between the metal cores.</p>1 aSahu, Puspanjali1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/fine-control-nanoparticle-sizes-and-size-distributions-temperature-and-ligand-effects-001344nas a2200205   4500008004100000022001400041245010500055210006900160260007300229300001200302490000800314520055700322653002100879653002300900653001500923653001800938100002100956700003000977856013101007       2014                        eng d  a0927-775700aDilution does the trick: role of mixed solvent evaporation in controlling nanoparticle self-assembly0 aDilution does the trick role of mixed solvent evaporation in con  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a142-1470 v4473 a<p>An easy and convenient way to prepare superlattices of amine capped gold nanoparticles is presented. It is clearly established that solvent evaporation significantly influences the nature of resulting superlattices and critically governs whether monolayer or multilayer superlattices are formed. More specifically, it is demonstrated that dilution of the nanoparticle dispersion with a similar solvent (but with different vapour pressure) is an expedient handle to control the nature of self-assembly. (C) 2014 Elsevier B.V. All rights reserved.</p>10aEvaporation rate10agold nanoparticles10aNucleation10aSelf-assembly1 aSahu, Puspanjali1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/dilution-does-trick-role-mixed-solvent-evaporation-controlling-nanoparticle-self-assembly-002105nas a2200229   4500008004100000022001400041245010900055210006900164260009500233300001000328490000800338520116200346653003301508653005001541653003601591653003001627100001701657700002501674700003001699700002101729856012501750       2014                        eng d  a0021-979700aSynthesis and in situ observation of 3D super lattices of gold nanoparticles using oil-in-water emulsion0 aSynthesis and in situ observation of 3D super lattices of gold n  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcAPR  a41-490 v4203 a<p>In this work oil-in-water emulsion has been successfully used as a confined environment to grow 3D superlattices of gold nanoparticles. The superlattices were grown from 5 nm uniform gold nanoparticles using slow destabilization method. The confined environment was created by forming a stable emulsion where the gold colloid suspended in toluene was used as oil phase. Superlattices were also formed in bulk solution using the same slow destabilization method. A comparative study reveals that compact superlattices form more readily inside the emulsion drops as compared to bulk precipitation. The unstable colloid (in bulk or as emulsion) was aged for various periods at 5 degrees C to form more compact superlattices. The best superlattices with sharp corners are observed when the superlattices are formed inside the emulsion and aged for a month. Two key parameters, the incubation temperature and anti-solvent concentration, are optimized to obtain larger superlattices with sharp features. A new method is also demonstrated for in situ observation of superlattice formation using an optical microscope. 2014 Elsevier Inc. All rights reserved.</p>10a3D nanocrystal superlattices10aIn situ observation of superlattice formation10aMonodisperse gold nanoparticles10aNanocrystal superlattices1 aDutta, Ankur1 aChakraborty, Jayanta1 aPrasad, Bhagavatula L. V.1 aSahu, Puspanjali  uhttps://library.ncl.res.in/content/synthesis-and-situ-observation-3d-super-lattices-gold-nanoparticles-using-oil-water-001704nas a2200157   4500008004100000022001400041245014800055210006900203260007100272300001600343490000700359520100500366100002101371700003001392856012401422       2014                        eng d  a0743-746300aTime and temperature effects on the digestive ripening of gold nanoparticles: is there a crossover from digestive ripening to ostwald ripening?0 aTime and temperature effects on the digestive ripening of gold n  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a10143-101500 v303 a<p>The effects of time and temperature on the gold nanoparticle sizes obtained by digestive ripening have been investigated. In digestive ripening, a polydisperse colloid, upon refluxing with a surface-active ligand in a solvent, gets converted to a nearly monodisperse one. In this study, a polydisperse gold nanoparticle system was heated in 4-tert-butyltoluene with hexadecanethiol at different temperatures, viz., 60, 90, 120, 150, and 180 degrees C for different time periods, and the trends in particle size variations were recorded. At lower temperatures such as 60 and 90 degrees C, after the initial narrowing of the size distribution, the particle sizes remain constant even though the refluxing step is continued for 24 h, substantiating the prevalence of the digestive ripening process. However, at elevated temperatures (120, 150, and 180 degrees C) particle sizes grow continuously, indicating a deviation from the digestive ripening behavior to an Ostwald ripening-type phenomenon.</p>1 aSahu, Puspanjali1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/time-and-temperature-effects-digestive-ripening-gold-nanoparticles-there-crossover-001460nas a2200181   4500008004100000022001400041245013300055210006900188260007300257300001000330490000800340520068400348653003701032653002801069100002101097700003001118856013001148       2015                        eng d  a0927-775700aPreparation of Ag(Shell)-Au(Core) nanoparticles by anti-galvanic reactions: are capping agents the ``real heroes'' of reduction?0 aPreparation of AgShellAuCore nanoparticles by antigalvanic react  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG  a30-350 v4783 a<p>The formation of Ag(shell)-Au(core) nanoparticles by the reduction of Ag+ ions on preformed Au NPs, mediated by the capping agents like dodecylamine is described. We clearly established that while monodisperse Ag(shell)-Au(core) structures can be formed in presence of weak surface binding ligands such as amines, strong binding ligands such as thiols, lead to formation of separate monometallic Au and Ag particles. Apart from highlighting the influence of metal-ligand binding strength on the formation of core-shell nanoparticle architectures, our study also provides an easy means to produce Ag( shell)-Au( core) structures. (C) 2015 Elsevier B.V. All rights reserved.</p>10aAg(shell)-Au(core) nanoparticles10aAnti-Galvanic reactions1 aSahu, Puspanjali1 aPrasad, Bhagavatula L. V.  uhttps://library.ncl.res.in/content/preparation-agshell-aucore-nanoparticles-anti-galvanic-reactions-are-capping-agents-real-101724nas a2200181   4500008004100000245006700041210006700108260000800175300001400183490000700197520113800204100002101342700001901363700001701382700001701399700003001416856009601446       2017                        eng d00aDigestive ripening of Au nanoparticles by multidentate ligands0 aDigestive ripening of Au nanoparticles by multidentate ligands  cJAN  a1943-19500 v333 a<p>The efficiency of multidentate ligands as digestive ripening agents for the preparation of monodisperse Au nanoparticles was investigated. This systematic investigation was performed using ligands possessing one, two, or three thiol moieties as ligands/digestive ripening agents. Our results clearly establish that among the different ligands, those that are monodentate and the use of temperatures in the range of 60 °C and 120 °C offer the best conditions for digestive ripening. In addition, when digestive ripening was carried out at lower temperatures (e.g., 60 °C), the nanoparticle size increased as the number of thiol groups per ligand increased. However, in the case of ligands possessing two and three thiol moieties when they are heated with polydispersed particles at higher temperatures (120 °C or 180 °C), the etching process dominates, which affects the quality of the nanoparticles in terms of their monodispersity. We conclude that the temperature-dependent strength of the interaction between the ligand headgroup and the nanoparticle surface plays a vital role in controlling the final particle sizes.</p>1 aSahu, Puspanjali1 aShimpi, Jayesh1 aLee, Han, Ju1 aLee, Randall1 aPrasad, Bhagavatula, L. V  uhttps://library.ncl.res.in/content/digestive-ripening-au-nanoparticles-multidentate-ligands