Swapnil R. Jadhav

Biorefinery: A Design Tool for Molecular Gelators

Molecular gels, the macroscopic products of a nanoscale bottom-up strategy, have emerged as a promising functional soft material. The prospects of tailoring the architecture of gelator molecules have led to the formation of unique, highly tunable gels for a wide spectrum of applications from medicine to electronics. Biorefinery is a concept that integrates the processes of converting biomass/renewable feedstock and the associated infrastructure used to produce chemicals and materials, which is analogous to petroleum-based refinery. The current review assimilates the successful efforts to demonstrate the prospects of the biorefinery concept for developing new amphiphiles as molecular gelators. Amphiphiles based on naturally available raw materials such as amygdalin, vitamin C, cardanol, arjunolic acid, and trehalose that possess specific functionality were synthesized using biocatalysis and/or chemical synthesis. The hydrogels and organogels obtained from such amphiphiles were conceptually demonstrated for diverse applications including drug-delivery systems and the templated synthesis of hybrid materials.

Lithium storage mechanisms in purpurin based organic lithium ion battery electrodes

Current lithium batteries operate on inorganic insertion compounds to power a diverse range of applications, but recently there is a surging demand to develop environmentally friendly green electrode materials. To develop sustainable and eco-friendly lithium ion batteries, we report reversible lithium ion storage properties of a naturally occurring and abundant organic compound purpurin, which is non-toxic and derived from the plant madder. The carbonyl/hydroxyl groups present in purpurin molecules act as redox centers and reacts electrochemically with Li-ions during the charge/discharge process. The mechanism of lithiation of purpurin is fully elucidated using NMR, UV and FTIR spectral studies. The formation of the most favored six membered binding core of lithium ion with carbonyl groups of purpurin and hydroxyl groups at C-1 and C-4 positions respectively facilitated lithiation process, whereas hydroxyl group at C-2 position remains unaltered.

Medium-Chain Sugar Amphiphiles: A New Family of Healthy Vegetable Oil Structuring Agents

Vegetable oils are frequently structured to enhance their organoleptic and mechanical properties. This is usually achieved by increasing the net amount of saturated and/or trans fatty acids in the oil. With the risk of coronary heart diseases associated with these fatty acids, the food industry is looking for better alternatives. In this context, the medium-chain dialkanoates of low-calorie sugars (sugar alcohol dioctanoates) are investigated as a healthy alternative structuring agent. Precursors of sugar amphiphiles, being FDA-approved GRAS materials, exhibited high cell viability at a concentration ~50 μg/mL. They readily formed nanoscale multilayered structures in an oil matrix to form a coherent network at low concentrations (1-3 wt %/v), which immobilized a wide range of oils (canola, soybean, and grapeseed oils). The structuring efficiency of sugar amphiphiles was computed in terms of mechanical, thermal, and structural properties and found to be a function of its type and concentration.

Self-assembled hydrogel fibers for sensing the multi-compartment intracellular milieu

Targeted delivery of drugs and sensors into cells is an attractive technology with both medical and scientific applications. Existing delivery vehicles are generally limited by the complexity of their design, dependence on active transport, and inability to function within cellular compartments. Here, we developed self-assembled nanofibrous hydrogel fibers using a biologically inert, low-molecular-weight amphiphile. Self-assembled nanofibrous hydrogels offer unique physical/mechanical properties and can easily be loaded with a diverse range of payloads. Unlike commercially available E. coli membrane particles covalently bound to the pH reporting dye pHrodo, pHrodo encapsulated in self-assembled hydrogel-fibers internalizes into macrophages at both physiologic (37°C) and sub-physiologic (4°C) temperatures through an energy-independent, passive process. Unlike dye alone or pHrodo complexed to E. coli, pHrodo-SAFs report pH in both the cytoplasm and phagosomes, as well the nucleus. This new class of materials should be useful for next-generation sensing of the intracellular milieu.

Self-standing, metal nanoparticle embedded transparent films from multi-armed cardanol conjugates through in situ synthesis

We report multi-armed/dendritic molecules having unsaturated side chains for generating scratch-free, self-standing cross-linked transparent films with embedded metal nanoparticles via autoxidation induced in situ synthesis.

Sugar based amphiphiles: easily accessible and efficient crude oil spill thickening agents

In this work, we demonstrate the use of biomass for the catalytic production of phase-selective gelators (PSGs) as a cost-effective, environmentally benign and ideal method for crude oil spill remediation, as well as execute the study exclusively in crude oil. The use of PSGs has recently provided great promise relative to that of their traditional counterparts. However, the use of PSGs with crude oil is much more complicated due to its complex composition. All of the current PSG methods are demonstrated with refined oils or do not employ eco-friendly methods like enzymatic synthesis. Our current project entails studying sugar alcohol-derived amphiphiles for their phase-selective gelation in crude oil; the PSGs are derived from renewable, benign materials and synthesized via a simple, single-step, enzymatic catalysis that required no purification. The results showed that, after a rigorous and systematic testing, the mannitol-derived amphiphile using 8-carbon alkyl chain length (M-8) turned out to be the best crude oil PSG among the studied amphiphiles. M-8 demonstrated a versatility towards thickening of different crude oil types, an efficient ability towards selective gelation of the oil (forming crude oil gel that is over sixty-one-times its mass and stable up to 109.7 °C) in a crude oil/water mixture, and an ability to form gel under practical situations such as seawater conditions. These qualities, in addition to the use of a simple and environmentally benign method to synthesize the structuring agents, make this amphiphile very practical in real life application.

A vegetable oil derived chemodosimeter for the selective detection of Hg2+ in aqueous media: a potential green laboratory method

An in situ-generated byproduct from the naturally occurring autoxidation of vegetable oil has been utilized to develop a thione-containing chemodosimeter for the selective detection of aqueous mercuric ions (Hg2+) at nanomolar concentrations through a one-pot synthesis/detection technique.