Publications by authors named "Mayakrishnan Gopiraman"

This study presents the first development of Cu (I) acylthiourea complexes (C1-C5) incorporated polycaprolactone/lignin (PCL/Lig) electrospun nanofiber composites (PCL/Lig@Cu(I)). Electrospinning conditions and mass ratios of PCL and lignin were optimized, followed by the incorporation of varying concentrations of Cu(I) complexes. Structural, morphological, and thermal properties were characterized using SEM, TEM, FT-IR, XRD, TGA and WCA analyses.

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This study aimed to develop polyvinyl alcohol (PVA) and kappa-carrageenan (κCA) biocomposite films using a Pickering emulsion technique for wound care applications. Juniper essential oil and modified sepiolite were incorporated to enhance functionality, with films prepared via solvent casting and characterized for structural, thermal, and mechanical properties. The PCOS-2 film exhibited the highest mechanical performance, with Young's modulus of 6.

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Article Synopsis
  • Biopolymer coatings, made from natural polymers like chitosan, alginate, and pectin, have been developed to extend the shelf life of edible fruits by creating barriers against water loss and microbial growth.
  • These coatings are eco-friendly and safe, addressing consumer preferences for natural preservation methods while minimizing post-harvest losses and waste.
  • The study emphasizes advancements in the formulation of these coatings, highlighting their potential as sustainable alternatives to synthetic preservatives in the fruit industry.
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  • The paper discusses the creation of melamine-based metal-organic frameworks (MOFs) using cheap melamine as an organic linker and cobalt, nickel, and iron as central metal ions for supercapacitor applications.
  • It presents techniques to optimize the molecular structures of these MOFs, which were characterized through various methods like X-ray diffraction, electron microscopy, and thermal analysis to confirm their stability and performance.
  • The electrochemical tests reveal that the specific capacitance values for Co-Me, Ni-Me, and Fe-Me in a potassium hydroxide electrolyte are significantly high, with Co-Me achieving 1267.36 F/g, indicating their efficiency in energy storage applications.
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Herein, for the very first time, we report a paper-like biomass, eggshell membrane (ESM), as a suitable platform for the fabrication of a colorimetric sensor (E-Cot). Green ethanolic extract, curcumin (CUR), was used as a sensing material to coat with the ESM. The present E-Cot effectively changed its color (yellow to red) in the real-time monitoring for chicken spoilage.

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The present review article discusses the elementary concepts of the sensor mechanism and various types of materials used for sensor applications. The electrospinning method is the most comfortable method to prepare the device-like structure by means of forming from the fiber structure. Though there are various materials available for sensors, the important factor is to incorporate the functional group on the surface of the materials.

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The use of artificial biomaterial with enhanced bioactivity for osteostimulation is a major research concern at present days. In this research, antibacterial and osteostimulative core-shell lignin nanoparticles (LgNP) were synthesized from alkali lignin using tetrahydrofuran (THF) as solvent via a simultaneous pH and solvent shifting technology. Later, LgNP-loaded polycaprolactone (PCL) composite nanofibers were fabricated via the electrospinning technique.

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Article Synopsis
  • * The CuNi/GO-I catalyst shows strong activity across various substrates like aryl iodides, bromides, and chlorides, achieving high yields and favorable turnover rates.
  • * Additionally, the CuNi/GO-I catalyst demonstrates excellent performance in reducing 4-nitrophenol and shows promising reusability, heterogeneity, and stability in reactions.
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Herein we report a very simple 'mix and heat' synthesis of a very fine Rh-nanoparticle loaded carbon fullerene-C60 nanocatalyst (Rh(0)NPs/Fullerene-C60) for the very first time. The preparation method used no reducing agent and capping agent to control the morphology of the nanocatalyst. Transmission electron microscopy (TEM) results confirmed the uniform decoration of small Rh-nanoparticles on the surface of fullerene-C60.

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Cu-containing activated carbon (eco-catalyst, Cu/HMPC, where 'C' defines 'carbon') was derived from a metal-hyperaccumulating mustard plant (HMP) by a simple chemical activation method. Transmission electron microscopy/selected area diffraction (HRTEM/SAED) results revealed that the Cu/HMPC has mainly three types of morphology [sheet-like morphology (2D), hollow-spheres (3D) and needle-like structures (1D)] which are interconnected. HRTEM-SAED, Raman and X-ray photoelectron spectroscopy (XPS) results confirmed the existence of Cu oxide species in Cu/HMPC.

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Highly active metal nanoparticle (MNP) supported cellulose nanofiber (CNF) composites (Au/CNF, Ni/CNF and Ag/CNF) were prepared for the reduction of 4- and 2-nitrophenols (4-NP and 2-NP) in water. Transmission electron microscopy (TEM) images showed that the ultrafine nanoparticles (Au, Ni and Ag NPs) were uniformly deposited on CNFs surface. The content of Au (9.

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The novel method, handspinning (HS), was invented by mimicking commonly observed methods in our daily lives. The use of HS allows us to fabricate carbon nanotube-reinforced nanofibers (CNT-reinforced nanofibers) by addressing three significant challenges: (i) the difficulty of forming nanofibers at high concentrations of CNTs, (ii) aggregation of the CNTs, and (iii) control of the orientation of the CNTs. The handspun nanofibers showed better physical properties than fibers fabricated by conventional methods, such as electrospinning.

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Herein, we report a comparative study of silver coated anionic cellulose nanocomposite before (CMC-Ag) and after (AgNPs/CMC) chemical reduction for antibacterial activity. Cellulose nanofibers were prepared by deacetylation of electrospun cellulose acetate nanofibers, which were then treated with sodium chloroacetate to prepare anionic cellulose nanofibers (CMC). Aqueous AgNO3 solution with different concentrations was employed to produce nanofiber composites.

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In this study, cellulose acetate nanofibers (CANFs) with a mean diameter of 325 ± 2.0 nm were electrospun followed by deacetylation and functionalization to produce anionic cellulose nanofibers (f-CNFs). The noble metal nanoparticles (RuNPs and AgNPs) were successfully decorated on the f-CNFs by a simple wet reduction method using NaBH4 as a reducing agent.

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We report the mechanical property and electromagnetic interference shielding effectiveness (EMI SE) of poly(vinyl alcohol) (PVA)/graphene and PVA/multi-walled carbon nanotube (MWCNT) composite nanofibers prepared by electrospinning. The metal (Cu) was deposited on the resultant PVA composite nanofibers using metal deposition technique in order to improve the mechanical properties and EMI shielding properties. The resulting PVA composite nanofibers and Cu-deposited corresponding nanofibers were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and wide angle X-ray diffraction (WAXD).

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Glucose, gellan gum, and hydroxypropyl cellulose were studied against the acid corrosion of cast iron by means of weight loss, potentiodynamic polarization, and AC impedance spectroscopy techniques. The inhibition efficiency was found to increase with increasing concentration of the inhibitors. The effect of immersion time and temperature were also studied.

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Continuous effort in research and development of nanofibers for apparel usage has been focused within their functional properties only. We investigated esthetic properties by producing colored cationic-cellulose nanofibers for the very first time for the potential application of apparel use. The cellulose acetate nanofibers were electrospun followed by deacetylation and cationization to produce functional cationic-cellulose nanofibers and then dyed with anionic reactive dyes.

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