Sustainable Materials

Biography:

Victor Girard began his PhD in 2021 at the University of Lorraine within the LERMAB after obtaining an ENSTIB engineering degree specializing in biorefining. The theme of his research is the extraction and valorization of nanolignins by coupling organosolv process and steam explosion.

Abstract:

Wood processing produces large amount of residues such as barks, shavings, sawdust, chips... For instance, to produce 1m3 of sawn timber, 1.7 to 2 m3 of log are required, generating nearly 50% of waste. The valorization of 1m3 of a log by sawing produces then about 8-10% ok barks, 10-13% of sawdust and 20-30% of other wood chips (data for beech and spruce). Pulping and wood energy are the main outlet for these wastes, while many other valorization possibilities could be envisaged.

Wood is a lignocellulosic material mainly composed of three polymeric fractions, cellulose, hemicellulose and lignin, which are highly entangled. As much as cellulose and hemicelluloses are well valorized today, lignin remains completely under-valued (thermal valorization). Thanks to its aromatic structure, lignin has many properties (biocide, antioxidant, UV-light blocker...) which could be useful in technical applications.

One of the ways of valorization of lignin still poorly explored is the production of nanolignins. Usually, the usefulness of nanoparticles lies in their size (< 100 nm), which provides them a high surface reactivity as well as physic and chemical properties that the materials would not have at a macroscopic scale. Nanoparticles are nowadays intentionally incorporated in many consumer-products as for example sunscreens, toothpastes... as well as in electronic devices and new medicinal treatments. The two goals of this work are to optimize a green extraction process of macrolignin from wood waste and then to optimize nanolignin production from lignin for a future valorization in both pharmaceutical and cosmetics applications.

Biography:

Mr. Ashraf Nawaz Khan is pursuing a Ph.D. at Indian Institute of Technology (IIT), Delhi. He completed graduation in Mechanical Engineering (B.Tech) in 2015. He obtained M. Tech Degree in Textile Engineering (2017). His area of research includes Thermoset and Thermoplastic based fibre reinforced composite materials, Preparation of different Hybrid yarn towpreg, Natural fibre based composite materials, Different weaving architecture preforms, Modelling and Simulation for Mechanical performance prediction, Developments of towpreg machines, etc. As of now, he published four research papers in reputed journals and several others are under communications. He attended various international conferences in past. Recently, he filed a patent for the development of the system for powder coating. He is awarded Research Travel Excellency Award (2022) from IIT Delhi for outstanding research and Best paper presentation at the conference (ICETT, 2019). Also. the merit scholarship during the entire graduation year (2011-2015).

Abstract:

The present work offers a suitable manufacturing technique for the development of very lightweight UHMWPE fiber-based fully thermoplastic composite materials. The weak interface formation with the highly viscous thermoplastic matrices is the major limitation. This major limitation is resolved through the powder-coated towpreg which is the primary substrate for the composite materials. The flexible powder-coated UHMWPE/LDPE towpreg results in homogenous matrix distribution throughout the composite on consolidation after hot-pressing. The produced ‘matrix impregnated’ flexible towpreg can be easily woven to any complex weave structure which is hard to achieve with other techniques such as melt impregnation, solution impregnation, etc. Furthermore, the current work made it possible to deposit charged LDPE powder onto the non-conductive UHMWPE fibres’ surface through the electrostatic powder spray technique uniquely and neatly. The improved technique extends the application of electrostatic-based powder coating to all fibres material (i.e, conductive or non-conductive) with a chemical-free methodology (environment friendly). Moreover, the fibre reinforced composite produced through the powder-coated towpreg has been compared with the composite prepared through other conventional techniques such as the Film stack technique, etc. The different material characterization such as DSC, TGA, XRD, DMA, etc, and mechanical characterization such as tensile, compression, shear test, drop weight impact test, abrasion wear, etc has been done to examine the utility of the single polymer UHMWPE composites. The end composite product finds its applicability in various fields such as Impact panels, Biomedical implants, and other lightweight high-strength Structural applications. The composite produced through powder-coated preform is found to be the superior in comparison to other laminates prepared through the Film stack technique in terms of mechanical performance as mentioned above. Furthermore, the fractography analysis has been carried out with the help of SEM, micro-CT, and other tools to extract the comprehensive information from the damaged samples.

Biography:

Dr. Subhasis Roy is working as Assistant Professor at Department of Chemical Engineering,

University of Calcutta, India. Dr. Roy received Ph.D. from Indian Institute of Technology, Kharagpur, India, in 2012. Before joining as a faculty member at Calcutta University, he worked as a Postdoctoral Researcher at Sungkyunkwan University, South Korea, Research Scientist at IISER, Kolkata, and worked as a visiting researcher Raman Fellow Ohio University. Dr. Roy has published more than 65 scientific research papers in peer-reviewed journals 35 conference proceedings. He has 15 book chapters to his credit and filed several patents.  Dr. Roy was awarded DST-Fast Track Young Scientist Start-Up Research Grant from SERB –DST, Mission innovation MI IC#5' DBT-DST joint funding grant, Teachers Associateship for Research Excellence (TARE) SERB –DST. He holds members of many professional societies  such as Royal Society of Chemistry (MRSC), National Academy of Sciences, India (NASI), reviewers, and editorial board member of many international journals. His expertise is in perovskite solar cells, multiferroic composite thin films, photocatalysts for water splitting, fuel cells, and hydrogen energy.

Abstract:

Developing thin film-based perovskite solar cells is on the lab scale by considering crucial factors, including degradation, instability, and toxicity, which are undesirable for perovskite photovoltaic technology.  In the case of perovskite solar cells, we worked on the controlled processing of nanostructured films for environment-friendly renewable energy sources. In this case, we successfully synthesized nanocrystals by hydrothermal process. The structure and morphology of all hybrid nanoparticles were characterized using a range of techniques such as X-ray diffraction, electron microscope, optical spectroscopic measurements. Several attempts have been made to improve the efficiency of the thin-film solar cell by the change of the fabrication process and optimizing environment-friendly materials addition. Several research works have been carried out under different experimental conditions towards the development of lead (Pb) free, environment-friendly and green perovskite solar cells, along with introducing a new, facile and effective method to develop stable and efficient perovskite solar cell at ambient condition. Fabricated solar cells were tested under different characterization techniques to explore the optical behavior, structural fundamentals, crystallinity, surface morphology, phase formation, defect and disorder, and electrical properties. 

Biography:

Abstract:

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Biography:

Abstract:

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Biography:

Abstract:

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