Publications by authors named "Srinivasa Rao Varanasi"

Isomers of trimethylbenzene (TMB) are the important constituent chemicals used in a variety of industrial applications, including the production of synthetic resins, insecticides, dyes, pigments, and pharmaceuticals. However, these applications require them in their purest form, mandating them to separate from their mixtures. Due to the similar physicochemical properties of the TMB isomers, traditional methods such as cryogenic distillation are very energy-expensive.

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Probing protein-membrane interactions is vital for understanding biological functionality for various applications such as drug development, targeted drug delivery, and creation of functional biomaterials for medical and industrial purposes. In this study, we have investigated interaction of Human Serum Albumin (HSA) with two different lipids, dipalmitoylphosphatidylglycerol (dDPPG) and dipalmitoylphosphatidylcholine (dDPPC), using Vibrational Sum Frequency Generation spectroscopy at different membrane fluidity values. In the liquid-expanded (LE) state of the lipid, HSA (at pH 3.

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We investigate the role of quantum confinement and photoluminescence (PL) lifetime of photoexcited charge carriers in semiconductor core/shell quantum dots (QDs) PL quenching due to surface modification. Surface modification is controlled by varying the number of dye molecules adsorbed onto the QD shell surface forming QD-dye nanoassemblies. We selected CuInS/ZnS (CIS) and InP/ZnS (InP) core/shell QDs exhibiting relatively weak (664 meV) and strong (1194 meV) confinement potentials for the conduction band electron.

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Vibrational sum frequency generation spectroscopy is used to understand the interactions of silica nanoparticles (SNPs) with a model cationic membrane (1,2-dipalmitoyl-3-(trimethylammonium)propane, DPTAP) by monitoring changes in the interfacial water and lipid structure at pH ∼ 2 and pH ∼ 11. Our study reveals that, at pH ∼ 11, SNPs are attracted to DPTAP due to electrostatic forces, causing changes in the interfacial water structure and lipid membrane. At high concentrations of SNPs (≥70 pM), the interfacial charge reversed from positive to negative, inducing the formation of new hydrogen-bonded structures and reorganization of water molecules.

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We report the ion transport mechanisms in succinonitrile (SN) loaded solid polymer electrolytes containing polyethylene oxide (PEO) and dissolved lithium bis(trifluoromethane)sulphonamide (LiTFSI) salt using molecular dynamics simulations. We investigated the effect of temperature and loading of SN on ion transport and relaxation phenomenon in PEO-LiTFSI electrolytes. It is observed that SN increases the ionic diffusivities in PEO-based solid polymer electrolytes and makes them suitable for battery applications.

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There has been a growing interest in the separation of aromatic hydrocarbon molecules from the petroleum stream using zeolite-based technologies. This led to numerous experimental and molecular simulation studies of the structural and dynamical properties of aromatic hydrocarbons under the confinement of microporous materials like zeolites. The understanding of the behavior of the isomers of the trimethylbenzene under confinement is crucial for their separation and purification from industrial streams.

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Water displays anomalous fast diffusion in narrow carbon nanotubes (CNTs), a behavior that has been reproduced in both experimental and simulation studies. However, little is reported on the effect of bulk water-CNT interfaces, which is critical to exploiting the fast transport of water across narrow carbon nanotubes in actual applications. Using molecular dynamics simulations, we investigate here the effect of such interfaces on the transport of water across arm-chair CNTs of different diameters.

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