Affiliation: Department of Mechanical Engineering, National University of Singapore, Singapore 117576
Interests: microwave processing; solidification processing; powder processing; light weight materials (aluminum and magnesium); composites/nanocomposites
One of the most serious challenges faced by humanity is the contamination of air, water, and soil bodies due to the restricted vision of the past researchers in the use of materials and technologies for the welfare of society. With increasing awareness of human health, researchers are becoming increasingly wiser and using materials that do not contaminate the planet. While this awareness is increasing, it is of paramount importance for the research to continue aggressively in this direction and for the industry to adopt and implement the novel ideas. Ecofriendly materials are materials, which should not contaminate or toxify the local environment during and after their use. Irrespective of whether they are legally or illegally dumped, their entry into the food chain should not adversely affect the health of living organisms. Accordingly, this section will welcome any aspect of research that promotes the use of eco-friendly materials with the hope that such materials will get attention beyond academia and will be adopted by industry to make Earth a better place to live.
Keywords: ecofriendly; non-toxic; materials; processing; applications
Keywords: ecofriendly; non-toxic; materials; processing; applications
ARTICLE | doi:10.20944/preprints202102.0450.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Wet spinning; Lanthanum oxide; Biochar; Chromate; Adsorption
Online: 22 February 2021 (08:51:53 CET)
Lanthanum chemical compound incorporates a sensible anionic complexing ability, however lacks stability at low pH scale. Biochar fibers will benefit of their massive space and plethoric useful teams on surface to support metal chemical compound. Herein, wet spinning technology was used to load La3+ onto sodium alginate fiber, and convert La3+ into La2O3 through carbonization. The La2O3 modified biochar (La-BC) fiber was characterized by SEM, XRD and XPS, etc. The adsorption experiment proved that La-BC showed excellent adsorption capacity for chromates, and its saturation adsorption capacity was about 104.93mg/g. The information suggested that the adsorption was in step with both Langmuir and Freundlich model, followed pseudo-second-order surface assimilation mechanics, which instructed that the Cr (VI) adsorption was characterized by single-phase and polyphase adsorption, mainly chemical adsorption. Thermodynamic parameter proved that the adsorption process was spontaneous and endothermic. The mechanistic investigation revealed that the mechanism of adsorption of Cr (VI) by La-BC may include electrostatic interaction, ligand exchange or complexation. Moreover, co-existing anions and regeneration experiments proved that La-BC was recyclable and had a good prospect in the field of chrome-containing wastewater removal.
ARTICLE | doi:10.20944/preprints202105.0608.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: nanocomposites; bacterial cellulose; ceria nanoparticles; thermal properties; swelling; mechanical behavior; biomedical applications; stem cells proliferation; gene expression
Online: 25 May 2021 (11:49:42 CEST)
A technique of fabrication of bacterial cellulose-based films with CeO2 nanofiller has been developed. The structural and morphological characteristics of the materials have been studied, their thermal and mechanical properties in dry and swollen states having been determined. The preparation methodology gives way to obtaining composites with the uniform distribution of nanoparticles. The catalytic effect of ceria regarding thermal oxidative destruction of cellulose was confirmed by TGA and DTA methods. An increase in CeO2 content leads to a rise in the elastic modulus (1.27-fold rise caused by the introduction of 5 wt.% of the nanofiller into polymer) and strength of the films. This effect is explained by the formation of additional links between polymer macro-chains via the nanoparticles’ surface. The materials fabricated are characterized by a limited swellability in water. Swelling causes a 20-30-fold drop in the stiffness of the material, the mechanical properties of the films in a swollen state remaining germane to their practical use. The application of the composite films in cell engineering as substrates for the stem cells proliferation has been studied. The increase in CeO2 content in the films enhanced the proliferative activity of embryonic mouse stem cells. The cells cultured on the scaffold containing 5 wt.% of ceria demonstrated increased cell survival and migration activity. Analysis of gene expression confirmed the improved cultivation conditions on CeO2-containing scaffolds.
REVIEW | doi:10.20944/preprints202011.0637.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: Bioremediation; Nanomaterials; Biosynthetic; Sustainable; Ecofriendly
Online: 25 November 2020 (12:14:51 CET)
Nanoparticles are widely used in the agricultural sector because of their distinctive properties. Studies have shown the influence of nanoparticles on plant growth and production. Nanoparticles act as effective carriers in the delivery of agrochemicals to plants. They provide site targeted delivery of nutrients and thus, prevents wastage of nutrients applied for plant growth and productivity. Bioremediation of pollutants is an emerging technology that provides bio-nano materials for the protection of agriculture from pollution. The aim of this review is to present and focus on the latest techniques used for the reduction of environmental pollution and improved agricultural production. This review speculates about the biosynthesis of nanomaterials from different sources like plants, fungi, and bacteria along with chemical and organic synthesis from carbon, silver, and gold. The role of nanoscience in detecting plant diseases and the removal of heavy metals. Application of Nanoscience in storing, production, processing, and transport of agricultural materials. It is also emphasized that Nanoscience may transform agriculture through the innovation of new techniques like Precision farming, improvement of plants to engross nutrients, targeted use of inputs, detection and control of diseases and withstand environmental pressures. Further, efforts have been made in describing that nanoparticles may act as a better substitute for agricultural plant growth and nutrition improvement by lowering the content of pollutants and pre-detection of diseases in plants. The biosynthetic route of nanomaterial synthesis could emerge as a better and safer option for environmental pollution reduction. Thus, nanoscience may increase agricultural production to feed a huge population in near future.
TECHNICAL NOTE | doi:10.20944/preprints202012.0190.v1
Subject: Engineering, Automotive Engineering Keywords: corona virus; environmental degradation; hydrogen economy; clean energy; renewable sources; non renewable sources; economic impact; environmental impact.
Online: 8 December 2020 (09:49:50 CET)
Covid-19 pandemic lockdown has slow down the world economic system. The pandemic has cleared the roads, close factories and grounded planes causing severe economic challenges. The damaging impact of the pandemic amid lockdown has been a blessing in guise for the environment because of significant drop in pollution level as transport and industrial sectors shutdown. Transport and industrial sectors are major contributors to environmental degradation through various emissions as a result of fossil fuel consumption. Energy consumed by transport and industrial sectors will have to shift to viable, readily available, economically and environmentally friendly with no carbon build up post Covid-19 pandemic. Hydrogen energy remains the best alternative option technologies containing green house gas emission and pollutions of several forms. Hydrogen holds the potential to provide a clean, reliable, renewable and economical source of energy for meeting the growing and unending global energy needs post pandemic. The present paper explores the economic feasibility and potential of hydrogen to serve as a competitive fuel option post pandemic. In this paper, the role of hydrogen as an energy carrier hydrogen economy structure, potential of hydrogen economy, hydrogen production methods, hydrogen application and the economic and environmental importance of hydrogen as a viable fuel option post covid-19 pandemic were discussed. There will be a surge in demand and investment for hydrogen economy post Covid-19.
ARTICLE | doi:10.20944/preprints202109.0184.v1
Subject: Engineering, Architecture, Building And Construction Keywords: cross-laminated timber; hygrothermal; energy; moisture; durability; tropical; passivhaus
Online: 10 September 2021 (11:21:01 CEST)
The uptake of buildings employing cross-laminated timber (CLT) assemblies and designed to Passivhaus standard has accelerated internationally over the past two decades due to several factors including design responses to the climate crisis by decarbonising the building stock. Structural CLT technology and the voluntary Passivhaus certification both show measurable benefits in reducing energy consumption, while contributing to durability and indoor comfort. However, there is a general lack of evidence to support a fast uptake of these technologies in Australia. This paper responds to the compelling need of providing quantitative data and adoption strategies, it explores their combined application as a potential pathway for climate-appropriate design of energy-efficient and durable mass timber envelope solutions for subtropical and tropical Australian climates. Hygrothermal risk assessments of interstitial condensation and mould growth of CLT wall assemblies inform best-practice design of mass timber buildings in hot and humid climates. This research found that the durability of mass timber buildings located in hot and humid climates may benefit from implementing the Passivhaus standard to manage interior conditions. The findings also suggested that climate-specific design of the wall assembly is critical for mass timber buildings, in conjunction with excellent stormwater management practices during construction and corrosion protection for metallic fasteners.