http://localhost:8080/xmlui/handle/123456789/4901 Research articles authored by NIIST researchers published in 2025 Tue, 21 Apr 2026 13:32:27 GMT 2026-04-21T13:32:27Z http://localhost:8080/xmlui/handle/123456789/5143 Title: Synergistic effect of a one-pot synthesised kaolinite–cerium melamine cyanurate hybrid for an improved metal protective coating Authors: Nithyaa, J; Nishanth, K G Abstract: This paper presents the cerium–melamine cyanurate (CeMC) complex as an anticorrosive pigment prepared by one-pot synthesis. Further, kaolinite is integrated to prepare KCeMC to improve the barrier performance of the anticorrosive coating. The effectiveness of the synthesised pigment-loaded epoxy coatings was assessed using electrochemical impedance spectroscopy in a 3.5 wt% NaCl solution. X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX) confirmed the release of the cathodic inhibitor Ce3+, which forms a protective layer over defective areas of the coating. A five-fold increase in the initial coat resistance was observed compared to the pristine epoxy, as measured by electrochemical impedance spectroscopy (EIS). A 1 wt% KCeMC loaded epoxy coating reveals better durability among all the synthesised pigment loaded coatings. The impedance results exhibited remarkable long-term durability, maintaining a high coating resistance of 7.70 × 109 Ω cm2 after 2 months of immersion in a saline medium. The improved protective properties of the epoxy coating containing KCeMC are attributed to the synergistic effects of cerium inhibition along with the barrier performance provided by kaolinite and melamine cyanurate. Wed, 01 Jan 2025 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/5143 2025-01-01T00:00:00Z http://localhost:8080/xmlui/handle/123456789/5138 Title: Self-Poled PVDF Infiltrated Nylon 11 Aerogels with Oriented Crystals for High-Performance Piezoelectric Energy Harvesters and Self-Powered Acoustic Sensors Authors: Ashitha, G; Athira, B S; Chandran, A; Surendran, K P; Gowd, E B Abstract: Efficient piezoelectric polymers with enhanced electromechanical conversion gain significant attention for energy harvesting and sensing applications. Among them, poly(vinylidene fluoride) (PVDF) and odd-nylons stand out due to their high piezoelectric coefficients and thermal stability. However, achieving a piezoelectric phase with a preferred crystal orientation for optimal performance remains challenging, particularly under mild processing conditions. In this study, a vacuum-assisted infiltration technique is introduced to fabricate PVDF-infiltrated nylon-11 (PVDFIPA11) aerogels with oriented polymer crystallites. Anisotropic nylon-11 aerogels, featuring aligned polymer crystals, serve as templates for PVDF infiltration under vacuum. This process facilitates the formation of highly oriented β phase PVDF crystals alongside γ phase nylon-11 crystals, yielding a fully self-poled system without the need for external poling. A piezoelectric nanogenerator (PENG) based on the PVDFIPA11 aerogel exhibits a high output voltage (peak-to-peak) of ≈45 Vpp and a peak power density of 2.2 Wm⁻3 significantly outperforming pristine PVDF and nylon-11 aerogels. Additionally, the PVDFIPA11 aerogel PENG is demonstrated as a self-powered acoustic sensor, effectively distinguishing sound signals at varying pressure levels. This work provides a scalable and practical strategy for developing self-poled piezoelectric polymer aerogels, paving the way for next-generation energy-harvesting devices and sensors. Thu, 03 Jul 2025 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/5138 2025-07-03T00:00:00Z http://localhost:8080/xmlui/handle/123456789/5137 Title: Optimization of Benzodithiophene-Based Copolymer and SWCNT Composite Films for Flexible Thermoelectric Generators Authors: Navin, J; Ignatious, V; Neethi, R; Dheepika, R; Riya, M; Tanjore, P Y; Biswapriya, D; Vijayakumar, C Abstract: This study investigates the thermoelectric (TE) properties of a benzodithiophene-based conjugated polymer (PBDTT-DPP) combined with single-walled carbon nanotubes (SWCNTs) for flexible, solution-processable thermoelectric generators (TEGs). Composite films are prepared with varying SWCNT content, achieving optimal performance at 50 wt.% SWCNT. Further optimization through FeCl₃ doping and thermal annealing at 200 °C significantly enhanced the electrical conductivity and overall TE performance. The doped and annealed composite film exhibited a power factor of 135 ± 8 µW mK−2 at 253 °C and a maximum ZT value of 0.17. Spectroscopic and electronic analyses revealed that doping and annealing realigned the energy bands and formed charge-transfer complexes, contributing to improved TE properties. Practical application is demonstrated through the fabrication of flexible, arc-shaped TEGs capable of harvesting energy from curved heat sources. The TEGs achieved a peak power output of 0.66 µW at ΔT = 100 K, showcasing its potential for low-grade waste heat recovery in industrial settings. This research advances the understanding of organic TE materials and offers promising solutions for sustainable energy harvesting from waste heat sources. Tue, 08 Jul 2025 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/5137 2025-07-08T00:00:00Z http://localhost:8080/xmlui/handle/123456789/5136 Title: Coconut oleosomes as a sustainable ingredient for food emulsion systems Authors: Anoop, A A; Ramees, P M; Ragavan, K V Abstract: Virgin coconut meal (VCM), a major by-product from the coconut milk processing stream, contains 30–40% oil, which seldom gets repurposed for food applications. In this study, we investigated the feasibility of VCM for the extraction of oleosomes and its suitability for the formulation of emulsion-based food systems such as vegan mayonnaise. Oleosome extraction parameters (pH 6.43 and feed-to-solvent ratio 1 : 1.96) were optimised using the response surface methodology. The extracted oleosomes contain 93.24 ± 1.53% of fat and 5.34 ± 0.3% of proteins, along with residual carbohydrates and moisture. Particle and morphological analyses indicated that oleosomes are monodisperse spherical particles with a mean diameter of 1.35 μm, and they are highly stable in the pH range of 6–9. The functional and thermal properties of oleosomes were interpreted through FTIR and DSC analysis. The colour profile of oleosomes is neutral with excellent whiteness, making them suitable for the formulation of food products. Rheological analysis of oleosome incorporated mayonnaise exhibited a uniform structured biphasic food matrix with soft solid-like consistency on par with commercial mayonnaise. Sensory analysis using a nine-point hedonic scale revealed that oleosome-based mayonnaise is more appealing than egg-based mayonnaise. Results from the above studies suggest that VCM is a suitable by-product for the extraction of oleosomes, and the extracted oleosomes can act as an emulsion with the potential to replace oil and emulsifiers in emulsion-based food products. The above process can be effectively applied for the extraction of oleosomes from cold-pressed meals/seed cakes. Fri, 30 May 2025 00:00:00 GMT http://localhost:8080/xmlui/handle/123456789/5136 2025-05-30T00:00:00Z