Showing papers by "Aninda J. Bhattacharyya published in 2009"
TL;DR: The crucial role of the drug carrier surface chemical moeities on the uptake and in vitro release of drug is discussed here in a systematic manner to aid in the design of delivery systems capable of sustained release of multiple drugs.
104 citations
TL;DR: The X-ray diffraction of single crystals obtained using in situ cryo-crystallography confirms directly the observations of the ionic conductivity measurements, and Fourier transform infrared spectroscopy and NMR line width measurements provide additional support to the proposition of ion transport in the prototype plastic crystalline electrolyte.
Abstract: Ion transport mechanism in lithium perchlorate (LiClO4)-succinonitrile (SN), a prototype of plastic crystalline soft matter electrolyte is discussed in the context of solvent configurational isomerism and ion solvation. Contributions of both solvent configurational isomerism and ion solvation are reflected in the activation energy for ion conduction in 0-1 M LiClO4-SN samples. Activation energy due to solvent configurational changes, that is, trans-gauche isomerism is observed to be a function of salt content and decreases in presence of salt (except at high salt concentrations, e.g. 1 M LiClO4-SN). The remnant contribution to activation energy is attributed to ion-association. The X-ray diffraction of single crystals obtained using in situ cryo-crystallography confirms directly the observations of the ionic conductivity measurements. Fourier transform infrared spectroscopy and NMR line width measurements provide additional support to our proposition of ion transport in the prototype plastic crystalline electrolyte.
79 citations
TL;DR: In this article, the simultaneous influence of surface functionality and pore size of mesoporous alumina (Al2O3) host on ibuprofen loading and release was reported.
48 citations
TL;DR: Observance of significant enhancement in direct electron transfer of Hb makes the SNTs also promising for application in biosensors and drug yield as function of time is found to be heavily dependent on the ultrasound impulse protocol.
Abstract: Silica nanotubes (SNTs) have been demonstrated here as a versatile host for controlled drug delivery and biosensing. The sol−gel template synthesized SNTs have a slow rate of drug release. Application of an external stimulus in the form of ultrasound to or chemical functionalization of synthesized SNT results in higher yield of drug release as well as yield of drug release varying linearly with time. In case of controlled drug delivery triggered by ultrasound, drug yield as function of time is found to be heavily dependent on the ultrasound impulse protocol. Impulses of shorter duration (∼0.5 min) and shorter time intervals between successive impulses resulted in higher drug yields. Confinement of hemoglobin (Hb) inside nanometer sized channels of SNT does not have any detrimental effect on the native protein structure and function. Observance of significant enhancement in direct electron transfer of Hb makes the SNTs also promising for application in biosensors.
44 citations
TL;DR: In this article, the first cycle capacity (at current rate = 10 mAg−1) for bare TiO2 nanotubes was 355 mAhg−1 (approximately 1.06 Li).
Abstract: Morphology and electrochemical performance of mixed crystallographic phase titania nanotubes for prospective application as anode in rechargeable lithium ion batteries are discussed. Hydrothermally grown nanotubes of titania (TiO2) and carbon-titania (C-TiO2) comprise a mixture of both anatase and TiO2 (B) crystallographic phases. The first cycle capacity (at current rate = 10 mAg−1) for bare TiO2 nanotubes was 355 mAhg−1 (approximately 1.06 Li), which is higher than both the theoretical capacity (335 mAhg−1) and the reported values for pure anatase and TiO2 (B) nanotubes. Higher capacity is attributed to a combination of the presence of mixed crystallographic phases of titania and trivial size effects. The surface area of bare TiO2 nanotubes was very high at 340 m2 g−1. C-TiO2 nanotubes showed a slightly lower first-cycle specific capacity of 307 mAhg−1, but the irreversible capacity loss in the first cycle decreased by half compared to bare TiO2 nanotubes. The C-TiO2 nanotubes also showed a better rate ...
42 citations
TL;DR: In this paper, the role of oxide surface chemical composition on ion transport in soggy sand electrolytes is discussed in a systematic manner, and it is shown that the attractive particle network in the case of the composite with unmodified aerosil silica (with surface silanol groups) is most favorable for percolation in ionic conductivity, as well as rendering a composite with beneficial elastic mechanical properties.
Abstract: The crucial role of oxide surface chemical composition on ion transport in "soggy sand" electrolytes is discussed in a systematic manner. A prototype soggy sand electrolytic system comprising aerosil silica functionalized with various hydrophilic and hydrophobic moieties dispersed in lithium perchlorate-ethylene glycol solution was used for the study. Detailed rheology studies show that the attractive particle network in the case of the composite with unmodified aerosil silica (with surface silanol groups) is most favorable for percolation in ionic conductivity, as well as rendering the composite with beneficial elastic mechanical properties: Though weaker in strength compared to the composite with unmodified aerosil particles, attractive particle networks are also observed in composites of aerosil particles with surfaces partially substituted with hydrophobic groups. The percolation in ionic conductivity is, however, dependent on the size of the hydrophobic moiety. No spanning attractive particle network was formed for aerosil particles with surfaces modified with stronger hydrophilic groups (than silanol), and as a result, no percolation in ionic conductivity was observed. The composite with hydrophilic particles was a sol, contrary to gels obtained in the case of unmodified aerosil, and partially substituted with hydrophobic groups.
31 citations
TL;DR: In this article, the concept of solid electrolyte synthesis from liquid is discussed in the light of various fundamental issues and in relation to its application to rechargeable lithium batteries, and the novelty of this approach is discussed.
Abstract: Soft matter provides diverse opportunities for the development of electrolytes for all solid state lithium batteries. Here we review soft matter solid electrolytes for lithium batteriesthat are primarily obtained starting from liquid electrolytic systems. This concept of solid electrolyte synthesis from liquid is significantly different from prevalent approaches. The novelty of our approach is discussed in the light of various fundamental issues and in relation to its application to rechargeable lithium batteries.
16 citations
TL;DR: Electrochemical investigations show reversible binding of n-donor liquid ligands, such as pyridine and its derivatives, and predictive variation in their redox potentials suggests an absence of any adverse effect on the structure and function of Hb confined inside nanometer-sized channels of SNTs.
Abstract: Investigations on the structure and function of hemoglobin (Hb) confined inside sol-gel template synthesized silica nanotubes (SNTs) have been discussed here. Immobilization of hemoglobin inside SNTs resulted in the enhancement of direct electron transfer during an electrochemical reaction. Extent of influence of nanoconfinement on protein activity is further probed via ligand binding and thermal stability studies. Electrochemical investigations show reversible binding of n-donor liquid ligands, such as pyridine and its derivatives, and predictive variation in their redox potentials suggests an absence of any adverse effect on the structure and function of Hb confined inside nanometer-sized channels of SNTs. Immobilization also resulted in enhanced thermal stability of Hb. The melting or denaturation temperature of Hb immobilized inside SNTs increase by approximately 4 degrees C as compared with that of free Hb in solution.
15 citations