Strategic Growth Area: Economical and Sustainable Materials (ESM)

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Now showing 1 - 20 of 190
  • A Study on Electron Acceptor of Carbonaceous Materials for Highly Efficient Hydrogen Uptakes
    Lee, Seul-Yi; Park, Ji-Hye; Heo, Young-Jung; Lee, Eun-Sang; Park, Soo-Jin (MDPI, 2021-12)
    Significant efforts have been directed toward the identification of carbonaceous materials that can be utilized for hydrogen uptake in order to develop on-board automotive systems with a gravimetric capacity of 5.5 wt.%, thus meeting the U.S. Department of Energy technical targets. However, the capacity of hydrogen storage is limited by the weak interaction between hydrogen molecules and the carbon surface. Cigarette butts, which are the most abundant form of primary plastic waste, remain an intractable environmental pollution problem. To transform this source of waste into a valuable adsorbent for hydrogen uptake, we prepared several forms of oxygen-rich cigarette butt-derived porous carbon (CGB-AC, with the activation temperature range of 600 and 900 & DEG;C). Our experimental investigation revealed that the specific surface area increased from 600 to 700 & DEG;C and then decreased as the temperature rose to 900 & DEG;C. In contrast, the oxygen contents gradually decreased with increasing activation temperature. CGB-AC700 had the highest H-2 excess uptake (QExcess) of 8.54 wt.% at 77 K and 20 bar, which was much higher than that of porous carbon reported in the previous studies. We found that the dynamic interaction between the porosity and the oxygen content determined the hydrogen storage capacity. The underlying mechanisms proposed in the present study would be useful in the design of efficient hydrogen storage because they explain the interaction between positive carbonaceous materials and negative hydrogen molecules in quadrupole orbitals.
  • Biomass Valorization to Bioenergy: Assessment of Biomass Residues' Availability and Bioenergy Potential in Nigeria
    Ezealigo, Uchechukwu Stella; Ezealigo, Blessing Nonye; Kemausuor, Francis; Achenie, Luke Ekem Kweku; Onwualu, Azikiwe Peter (MDPI, 2021-12)
    The bioenergy sector in Nigeria currently lacks a proper assessment of resource availability. In this study, we investigated the bioenergy potential of agricultural residues and municipal solid and liquid waste using data from 2008 to 2018, and we applied a computational and analytical approach with mild assumptions. The technical potential for the production of cellulosic ethanol and biogas was estimated from the available biomass. It was discovered that higher energy was generated from biogas than cellulosic ethanol for the same type of residue. The available crop residue technical potential of 84 Mt yielded cellulosic ethanol and biogas of 14,766 ML/yr (8 Mtoe) and 15,014 Mm(3)/yr (13 Mtoe), respectively. Biogas has diverse applications ranging from heat to electric power generation and therefore holds great potential in solving the current electricity crisis in Nigeria. It will also position the nation towards achieving the 7th sustainable development goal (SDG 7) on clean and affordable energy.
  • A Tool for the Assessment of Forest Biomass as a Source of Rural Sustainable Energy in Natural Areas in Honduras
    Bardales, Menelio; Bukowski, Catherine; Molina-Moreno, Valentín; Gálvez-Sánchez, Francisco Jesús; Ramos-Ridao, Ángel Fermín (MDPI, 2022-09-06)
    Forest biomass as a rural sustainable energy source has received much attention in recent years due to its major economic, social, and environmental benefits. This research focuses on an adapted methodology based on parameters of the Evaluation of Ecological Integrity for using site-specific information as a tool for the assessment of forest biomass as a source of rural sustainable energy in Honduras, focusing on the Central American Pine–Oak Forests. The parameters used were Percentage of Forest Cover (FC), Patch Area (AREA), Fractal Dimension Index (FRAC), and Proximity Index (PROX). The goal was an average index rating of 5 for an ecosystem which is intact or in its natural state. The findings showed an ecosystem degradation that was outside the range of acceptable variation with a simple average of 1.75, which is far lower than the target rating of five (5.0); the forest cover loss was 40% of the total area. This surprising finding shows that immediate intervention is required to maintain this ecosystem, and that if action is not taken, the ecosystem will suffer severe degradation. Decision makers must consider this methodology for using site-specific information and ensure that local communities are involved in restoring the ecosystem.
  • Wood for Application in Electrochemical Energy Storage Devices
    Shan, Xiaofei; Wu, Jing; Zhang, Xiaotao; Wang, Li; Yang, Junli; Chen, Zhangjing; Yu, Jianfang; Wang, Ximing (Elsevier, 2021-12-22)
    Nowadays, achieving powerful electrochemical energy conversion and storage devices is a major challenge of our society. Wood is a biodegradable and renewable material that naturally has a hierarchical porous structure, excellent mechanical performance, and versatile physicochemical properties. Wood-based materials and its derivatives are endowed with great potential as resources to fabricate advanced materials for energy storage, flexible electronics, and clean energy. Herein, we comprehensively overview the methodologies applied for the synthesis of various electrochemical energy storage systems and devices (e.g., supercapacitor, battery, catalytic hydrogen evolution, etc.), the strategies for tailoring the structures and conductivity, as well as their impact on electrochemical performance (energy and power density and long-term durability). Finally, an outlook of future opportunities and prospects in the synthesis and application of electrochemical energy storage is also presented.
  • Cascade degradation and upcycling of polystyrene waste to high-value chemicals
    Xu, Zhen; Pan, Fuping; Sun, Mengqi; Xu, Jianjun; Munyaneza, Nuwayo Eric; Croft, Zacary L.; Cai, Gangshu; Liu, Guoliang (National Academy of Sciences, 2022-08-23)
    Plastic waste represents one of the most urgent environmental challenges facing humankind. Upcycling has been proposed to solve the low profitability and high market sensitivity of known recycling methods. Existing upcycling methods operate under energy-intense conditions and use precious-metal catalysts, but produce low-value oligomers, monomers, and common aromatics. Herein, we report a tandem degradation-upcycling strategy to exploit high-value chemicals from polystyrene (PS) waste with high selectivity. We first degrade PS waste to aromatics using ultraviolet (UV) light and then valorize the intermediate to diphenylmethane. Low-cost AlCl3 catalyzes both the reactions of degradation and upcycling at ambient temperatures under atmospheric pressure. The degraded intermediates can advantageously serve as solvents for processing the solid plastic wastes, forming a self-sustainable circuitry. The low-value-input and high-value-output approach is thus substantially more sustainable and economically viable than conventional thermal processes, which operate at high-temperature, high-pressure conditions and use precious-metal catalysts, but produce low-value oligomers, monomers, and common aromatics. The cascade strategy is resilient to impurities from plastic waste streams and is generalizable to other high-value chemicals (e.g., benzophenone, 1,2-diphenylethane, and 4-phenyl-4-oxo butyric acid). The upcycling to diphenylmethane was tested at 1-kg laboratory scale and attested by industrial-scale techno-economic analysis, demonstrating sustainability and economic viability without government subsidies or tax credits.
  • Sustainable Electric Vehicle Batteries for a Sustainable World: Perspectives on Battery Cathodes, Environment, Supply Chain, Manufacturing, Life Cycle, and Policy
    Yang, Zhijie; Huang, Haibo; Lin, Feng (Wiley, 2022-05-10)
    Li-ion batteries (LIBs) can reduce carbon emissions by powering electric vehicles (EVs) and promoting renewable energy development with grid-scale energy storage. However, LIB production and electricity generation still heavily rely on fossil fuels at present, resulting in major environmental concerns. Are LIBs as environmentally friendly and sustainable as expected at the current stage? In the past 5 years, a skyrocketing growth of the EV market has been witnessed. LIBs have garnered huge attention from academia, industry, government, non-governmental organizations, investors, and the general public. Tremendous volumes of LIBs are already implemented in EVs today, with a continuing, exponential growth expected for the years to come. When LIBs reach their end-of-life in the next decades, what technologies can be in place to enable second-life or recycling of batteries? Herein, life cycle assessment studies are examined to evaluate the environmental impact of LIBs, and EVs are compared with internal combustion engine vehicles regarding environmental sustainability. To provide a holistic view of the LIB development, this Perspective provides insights into materials development, manufacturing, recycling, legislation and policy, and beyond. Last but not least, the future development of LIBs and charging infrastructures in light of emerging technologies are envisioned.
  • Conversion of Food Waste into 2,3-Butanediol via Thermophilic Fermentation: Effects of Carbohydrate Content and Nutrient Supplementation
    Yu, Dajun; O’Hair, Joshua; Poe, Nicholas; Jin, Qing; Pinton, Sophia; He, Yanhong; Huang, Haibo (MDPI, 2022-01-10)
    Fermentation of food waste into 2,3-butanediol (2,3-BDO), a high-value chemical, is environmentally sustainable and an inexpensive method to recycle waste. Compared to traditional mesophilic fermentation, thermophilic fermentation can inhibit the growth of contaminant bacteria, thereby improving the success of food waste fermentation. However, the effects of sugar and nutrient concentrations in thermophilic food waste fermentations are currently unclear. Here, we investigated the effects of sugar and nutrients (yeast extract (YE) and peptone) concentrations on 2,3-BDO production from fermenting glucose and food waste media using the newly isolated thermophilic Bacillus licheniformis YNP5-TSU. When glucose media was used, fermentation was greatly affected by sugar and nutrient concentrations: excessive glucose (>70 g/L) slowed down the fermentation and low nutrients (2 g/L YE and 1 g/L peptone) caused fermentation failure. However, when food waste media were used with low nutrient addition, the bacteria consumed all 57.8 g/L sugars within 24 h and produced 24.2 g/L 2,3-BDO, equivalent to a fermentation yield of 0.42 g/g. An increase in initial sugar content (72.9 g/L) led to a higher 2,3-BDO titer of 36.7 g/L with a nearly theoretical yield of 0.47 g/g. These findings may provide fundamental knowledge for designing cost-effective food waste fermentation to produce 2,3-BDO.
  • Enabling Intelligent Recovery of Critical Materials from Li-ion Battery through Direct Recycling Process with Internet-of-Things
    Lu, Yingqi; Han, Xu; Li, Zheng (MDPI, 2021-11-24)
    The rapid market expansion of Li-ion batteries (LIBs) leads to concerns over the appropriate disposal of hazardous battery waste and the sustainability in the supply of critical materials for LIB production. Technologies and strategies to extend the life of LIBs and reuse the materials have long been sought. Direct recycling is a more effective recycling approach than existing ones with respect to cost, energy consumption, and emissions. This approach has become increasingly more feasible due to digitalization and the adoption of the Internet-of-Things (IoT). To address the question of how IoT could enhance direct recycling of LIBs, we first highlight the importance of direct recycling in tackling the challenges in the supply chain of LIB and discuss the characteristics and application of IoT technologies, which could enhance direct recycling. Finally, we share our perspective on a paradigm where IoT could be integrated into the direct recycling process of LIBs to enhance the efficiency, intelligence, and effectiveness of the recycling process.
  • 3D printing of lignin: Challenges, opportunities and roads onward
    Ebers, L. -S.; Arya, Aditi; Bowland, C. C.; Glasser, Wolfgang G.; Chmely, S. C.; Naskar, A. K.; Laborie, Marie-Pierre Genevieve (2021-06)
    As the second most abundant biopolymer on earth, and as a resource recently becoming more available in separated and purified form on an industrial scale due to the development of new isolation technologies, lignin has a key role to play in transitioning our material industry towards sustainability. Additive manufacturing (AM), the most efficient-material processing technology to date, has likewise made great strides to promote sustainable industrial solutions to our needs in engineered products. Bringing lignin research to AM has prompted the emergence of the nascent "lignin 3D printing" field. This review presents the recent state of art of this promising field and highlights its challenges and opportunities. Following a review of the industrial availability, molecular attributes, and associated properties of technical lignins, we review R&D efforts at implementing lignin systems in extrusion-based and stereolithography (SLA) printing technologies. Doing so underlines the adage of lignin research that "all lignins are not created equal," and stresses the opportunity nested in this chemical diversity created mostly by differences in isolation conditions to molecularly select and tune the attributes of technical lignin systems towards desirable properties, be it by modification or polymer blending. Considering the AM design process in its entirety, we finally propose onward routes to bring the full potential to this emerging field. We hope that this review can help promote the unique value and overdue industrial role of lignin in sustainable engineered materials and products.
  • Self-healing liquid metal composite for reconfigurable and recyclable soft electronics
    Tutika, Ravi; Tahidul Haque, A.B.M.; Bartlett, Michael D. (Springer Nature, 2021)
    Soft electronics and robotics are in increasing demand for diverse applications. However, soft devices typically lack rigid enclosures which can increase their susceptibility to damage and lead to failure and premature disposal. This creates a need for soft and stretchable functional materials with resilient and regenerative properties. Here we show a liquid metal-elastomerplasticizer composite for soft electronics with robust circuitry that is self-healing, reconfigurable, and ultimately recyclable. This is achieved through an embossing technique for ondemand formation of conductive liquid metal networks which can be reprocessed to rewire or completely recycle the soft electronic composite. These skin-like electronics stretch to 1200% strain with minimal change in electrical resistance, sustain numerous damage events under load without losing electrical conductivity, and are recycled to generate new devices at the end of life. These soft composites with adaptive liquid metal microstructures can find broad use for soft electronics and robotics with improved lifetime and recyclability.
  • A Versatile Method for Preparing Polysaccharide Conjugates via Thiol-Michael Addition
    Chen, Junyi; Ma, Xutao; Edgar, Kevin J. (MDPI, 2021-06-08)
    Polysaccharide conjugates are important renewable materials. If properly designed, they may for example be able to carry drugs, be proactive (e.g., with amino acid substituents) and can carry a charge. These aspects can be particularly useful for biomedical applications. Herein, we report a simple approach to preparing polysaccharide conjugates. Thiol-Michael additions can be mild, modular, and efficient, making them useful tools for post-modification and the tailoring of polysaccharide architecture. In this study, hydroxypropyl cellulose (HPC) and dextran (Dex) were modified by methacrylation. The resulting polysaccharide, bearing α,β-unsaturated esters with tunable DS (methacrylate), was reacted with various thiols, including 2-thioethylamine, cysteine, and thiol functional quaternary ammonium salt through thiol-Michael addition, affording functionalized conjugates. This click-like synthetic approach provided several advantages including a fast reaction rate, high conversion, and the use of water as a solvent. Among these polysaccharide conjugates, the ones bearing quaternary ammonium salts exhibited competitive antimicrobial performance, as supported by a minimum inhibitory concentration (MIC) study and tracked by SEM characterization. Overall, this methodology provides a versatile route to polysaccharide conjugates with diverse functionalities, enabling applications such as antimicrobial activity, gene or drug delivery, and biomimicry.
  • Experimental Investigation of Sound Transmission Loss in Concrete Containing Recycled Rubber Crumbs
    Chalangaran, Navid; Farzampour, Alireza; Paslar, Nima; Fatemi, Hadi (Technopress, 2021-05-15)
    This study represents procedures and material to improve sound transmission loss through concrete without having any significant effects on mechanical properties. To prevent noise pollution damaging effects, and for reducing the transmission of the noises from streets to residential buildings, sound absorbing materials could be effectively produced. For this purpose, a number of several mixture designs have been investigated in this study to reduce the sound transmission through concrete, including control sample and three mixtures with recycled rubber with sizes of from 1mm up to 3 mm to limit the sound transmission. The rubber is used as a replacement of 5, 10, and 15 percent of sand aggregates. First, 7, 14 and 28-day strengths of the concrete have been measured. Subsequently, the sound transmission losses through the samples have been measured at the range of 63 Hz up to 6300 Hz by using impedance tube and the transfer function. The results show specimens containing 15% fine-grained crumbs, the loss of sound transmission were up to 190%, and for samples with 15% coarse-grained rubber, the loss of sound transmission were up to 228%, respectively. It is shown that concrete with recycled rubber crumbs could effectively improve environmental noise absorption.
  • Porous organic materials offer vast future opportunities
    Liu, Tianyu; Liu, Guoliang (2020-10-02)
    In light of the surging research on porous organic materials, we herein discuss the key issues of their porous structures, surface properties, and end functions. We also present an outlook on emerging opportunities, new applications, and data science-assisted materials discovery.
  • Enhanced heavy metal removal from an aqueous environment using an eco-friendly and sustainable adsorbent
    Zhang, Wanqi; An, Yuhong; Li, Shujing; Liu, Zhechen; Chen, Zhangjing; Ren, Yukun; Wang, Sunguo; Zhang, Xiaotao; Wang, Ximing (2020-10-05)
    Thiol-lignocellulose sodium bentonite (TLSB) nanocomposites can effectively remove heavy metals from aqueous solutions. TLSB was formed by using-SH group-modified lignocellulose as a raw material, which was intercalated into the interlayers of hierarchical sodium bentonite. Characterization of TLSB was then performed with BET, FTIR, XRD, TGA, PZC, SEM, and TEM analyses. The results indicated that thiol-lignocellulose molecules may have different influences on the physicochemical properties of sodium bentonite, and an intercalated-exfoliated structure was successfully formed. The TLSB nanocomposite was subsequently investigated to validate its adsorption and desorption capacities for the zinc subgroup ions Zn(II), Cd(II) and Hg(II). The optimum adsorption parameters were determined based on the TLSB nanocomposite dosage, concentration of zinc subgroup ions, solution pH, adsorption temperature and adsorption time. The results revealed that the maximum adsorption capacity onto TLSB was 357.29 mg/g for Zn(II), 458.32 mg/g for Cd(II) and 208.12 mg/g for Hg(II). The adsorption kinetics were explained by the pseudo-second-order model, and the adsorption isotherm conformed to the Langmuir model, implying that the dominant chemical adsorption mechanism on TLSB is monolayer coverage. Thermodynamic studies suggested that the adsorption is spontaneous and endothermic. Desorption and regeneration experiments revealed that TLSB could be desorbed with HCl to recover Zn(II) and Cd(II) and with-HNO3 to recover Hg(II) after several consecutive adsorption/desorption cycles. The adsorption mechanism was investigated through FTIR, EDX and SEM, which demonstrated that the introduction of thiol groups improved the adsorption capacity. All of these results suggested that TLSB is an eco-friendly and sustainable adsorbent for the extraction of Zn(II), Cd(II) and Hg(II) ions in aqueous media.
  • Biodegradable Poly(Lactic Acid) Nanocomposites for Fused Deposition Modeling 3D Printing
    Bardot, Madison; Schulz, Michael D. (MDPI, 2020-12-21)
    3D printing by fused deposition modelling (FDM) enables rapid prototyping and fabrication of parts with complex geometries. Unfortunately, most materials suitable for FDM 3D printing are non-degradable, petroleum-based polymers. The current ecological crisis caused by plastic waste has produced great interest in biodegradable materials for many applications, including 3D printing. Poly(lactic acid) (PLA), in particular, has been extensively investigated for FDM applications. However, most biodegradable polymers, including PLA, have insufficient mechanical properties for many applications. One approach to overcoming this challenge is to introduce additives that enhance the mechanical properties of PLA while maintaining FDM 3D printability. This review focuses on PLA-based nanocomposites with cellulose, metal-based nanoparticles, continuous fibers, carbon-based nanoparticles, or other additives. These additives impact both the physical properties and printability of the resulting nanocomposites. We also detail the optimal conditions for using these materials in FDM 3D printing. These approaches demonstrate the promise of developing nanocomposites that are both biodegradable and mechanically robust.
  • Heparin-based hydrogel scaffolding alters the transcriptomic profile and increases the chemoresistance of MDA-MB-231 triple-negative breast cancer cells
    Menon, Nidhi; Dang, Ha X.; Datla, Udaya Sree; Moarefian, Maryam; Lawrence, Christopher B.; Maher, Christopher A.; Jones, Caroline N. (2020-05-21)
    The tumor microenvironment plays a critical role in the proliferation and chemoresistance of cancer cells. Growth factors (GFs) are known to interact with the extracellular matrix (ECM) via heparin binding sites, and these associations influence cell behavior. In the present study, we demonstrate the ability to define signals presented by the scaffold by pre-mixing growth factors, such as epidermal growth factor, into the heparin-based (HP-B) hydrogel prior to gelation. In the 3D biomimetic microenvironment, breast cancer cells formed spheroids within 24 hours of initial seeding. Despite higher number of proliferating cells in 2D cultures, 3D spheroids exhibited a higher degree of chemoresistance after 72 hours. Further, our RNA sequencing results highlighted the phenotypic changes influenced by solid-phase GF presentation. Wnt/beta-catenin and TGF-beta signaling were upregulated in the cells grown in the hydrogel, while apoptosis, IL2-STAT5 and PI3K-AKT-mTOR signaling were downregulated. With emerging technologies for precision medicine in cancer, this nature of fine-tuning the microenvironment is paramount for cultivation and downstream characterization of primary cancer cells and rare circulating tumor cells (CTCs), and effective screening of chemotherapeutic agents.
  • In-Field Performance of Biomass Balers
    Grisso, Robert D.; Webb, Erin G.; Cundiff, John S. (MDPI, 2020-12-04)
    Herbaceous biomass will contribute significantly to meeting renewable energy goals. Harvesting equipment for hay is generally suitable for mowing, raking, and baling grasses such as switchgrass; however, there is a need for field data to better understand machine performance in energy crops. The purpose of this study was to collect field data to estimate baler field capacity, throughput, and speed. Data gathered with a Differential Global Positioning System (DGPS) unit during baling provided time-motion studies of baler productivity. Six fields were used to compare field capacity, speed, and throughput results from four round balers and one large-square baler. The results show that in-field performance of round balers is significantly affected by yield, but that the relationship can be represented with machinery management concepts, knowledge of maximum throughput, and wrap-eject time. Baler performance will be overestimated if the yield, maximum throughput, and wrap-eject time are not correctly accounted for.
  • Economical and Sustainable Materials Newsletter, Fall 2020
    (Virginia Tech, 2020-09-29)
    This is the Fall 2020 newsletter for the Economical and Sustainable Materials Strategic Growth Area. Read more to learn how Materials SGA faculty and scholars have contributed to the world of Materials Science.
  • Nano Silica and Metakaolin Effects on the Behavior of Concrete Containing Rubber Crumbs
    Chalangaran, Navid; Farzampour, Alireza; Paslar, Nima (MDPI, 2020-11-08)
    The excessive production of worn tires remaining from the transportation system and the lack of proper procedures to recycle or reuse these materials have caused critical environmental issues. Due to the rubber’s toughness, this material could be implemented to increase concrete toughness, and by crushing the tires concrete aggregates can be replaced proportionally with rubber crumbs and large quantities of scrapped rubber. However, this substitution decreases the concrete strength. In this study, crushed rubber with sizes from 1 to 3 mm and 3 to 6 mm were replaced by 5%, 10%, and 15% sand; the combination of two additives of nano silica and metakaolin additives with optimum values was used to compensate the degradation of the strength and improve the workability of the concrete. Moreover, the compressive strength, tensile behavior, and modulus of elasticity were measured and compared. The results indicate that the optimum use of nano silica and metakaolin additives could compensate the negative effects of the rubber material implementation in the concrete mixture while improving the overall workability and flowability of the concrete mixture.
  • Novel Electrospun Pullulan Fibers Incorporating Hydroxypropyl-β-Cyclodextrin: Morphology and Relation with Rheological Properties
    Poudel, Deepak; Swilley-Sanchez, Sarah; O'Keefe, Sean F.; Matson, John B.; Long, Timothy E.; Fernández-Fraguas, Cristina (MDPI, 2020-10-31)
    Fibers produced by electrospinning from biocompatible, biodegradable and naturally occurring polymers have potential advantages in drug delivery and biomedical applications because of their unique functionalities. Here, electrospun submicron fibers were produced from mixtures containing an exopolysaccharide (pullulan) and a small molecule with hosting abilities, hydroxypropyl-β-cyclodextrin (HP-β-CD), thus serving as multi-functional blend. The procedure used water as sole solvent and excluded synthetic polymers. Rheological characterization was performed to evaluate the impact of HP-β-CD on pullulan entanglement concentration (CE); the relationship with electrospinnability and fiber morphology was investigated. Neat pullulan solutions required three times CE (~20% w/v pullulan) for effective electrospinning and formation of bead-free nanofibers. HP-β-CD (30% w/v) facilitated electrospinning, leading to the production of continuous, beadless fibers (average diameters: 853-1019 nm) at lower polymer concentrations than those required in neat pullulan systems, without significantly shifting the polymer CE. Rheological, Differential Scanning Calorimetry (DSC) and Dynamic Light Scattering (DLS) measurements suggested that electrospinnability improvement was due to HP-β-CD assisting in pullulan entanglement, probably acting as a crosslinker. Yet, the type of association was not clearly identified. This study shows that blending pullulan with HP-β-CD offers a platform to exploit the inherent properties and advantages of both components in encapsulation applications.