Polymeric surfactants as ideal substitutes for sustainable corrosion protection: A perspective on colloidal and interface properties.

Surfactants are well known for their colloidal and corrosion inhibition potential (CIP) due to their strong propensity to interact with metallic surfaces. However, because of their small molecular size and the fact that they are only effective at relatively high concentrations, their application in aqueous phase corrosion inhibition is often restricted. Polymeric surfactants, a unique class of corrosion inhibitors, hold the potential to eradicate the challenges associated with using surfactants in corrosion inhibition. They strongly bond with the metallic surface and offer superior CIP because of their macromolecular polymeric structure and abundance of polar functional groups. In contrast to conventional polymeric corrosion inhibitors, the inclusion of polar functional groups also aids in their solubilization in the majority of popular industry-based electrolytes. Some of the major functional groups present in polymeric surfactants used in corrosion mitigation include O (ether), glycidyl (cyclic ether), -CONH2 (amide), -COOR (ester), -SO3H (sulfonic acid), -COOH (carboxyl), -NH2 (amino), - + NR3/- + NHR2/- + NH2R/- + NH3 (quaternary ammonium), -OH (hydroxyl), -CH2OH (hydroxymethyl), etc. The current viewpoint offers state-of-the-art information on polymer surfactants as newly developing ideal alternatives for conventional corrosion inhibitors. The industrial scale-up, colloidal, coordination, adsorption properties, and structural requirements of polymer surfactants have also been established based on the knowledge obtained from the literature. Finally, the challenges, drawbacks, and potential benefits of using polymer surfactants have also been discussed.

Novel corona virus (COVID-19); Global efforts and effective investigational medicines: A review.

Coronavirus disease-2019 (COVID-19), associated with the outbreak of deadly virus originating in Wuhan, China, is now a global health emergency and a matter of serious concern. Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is rapidly spreading worldwide, and WHO declared the outbreak of this disease a pandemic on March 11, 2020. Though some of the countries have succeeded in slowing down the rate of the spread of this pandemic, most the countries across the globe are still continuing to experience an increasing trend in the growth and spread of this deadly disease. Hence, in the current scenario, is has now become essential to control and finally irradicate this deadly disease using an effective vaccine. One can expect the prominent role of already available antivirals, antibodies and anti-inflammatory drugs in the market, in this pandemic. Immunomodulatory and biological therapeutics are also in the high expectations to combat COVID-19. RNA based vaccines might be more advantageous over traditional vaccines, to deal with the pandemic threat. Aiming towards this direction, clinical trials for SARS-CoV-2 vaccine are currently underway all across the globe. Currently, about 150 health related organizations and research labs are in the progress for the evolution of COVID-19 vaccines, globally. The initial aim of these clinical trials is to assess vaccine's safety, which is tested in Phase I/II/III studies where the primary outcomes typically examine the frequency of adverse effects. The vaccine is about to undergo phase III testing in several countries such as India, USA, South Africa, Brazil and England. US Government, under Operation Wrap Speed is even ready to sponsor three candidates, namely-The University of Oxford and AstraZeneca's AZD1222; Moderna's mRNA-1273; and Pfizer and BioNTech's BNT162 for Phase III trials.

Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers.

Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results.