Browsing by Author "Thakur, Md Shajedul Hoque"

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    Additive Manufacturing of Bio-inspired Sustainable Composites
    (2024-08-08) Thakur, Md Shajedul Hoque; Rahman, Muhammad M; Ajayan, Pulickel M
    Material efficiency is a key element of sustainable development. This can be achieved by recycling and reducing material waste, as well as through innovative designs that optimize material usage. Nature has many examples of complex hierarchical designs yielding lightweight efficient structural materials. Additive manufacturing enables the fabrication of material-optimized structures and material recycling at the product’s end-of-life. Thus, addressing both aspects- sustainable materials and sustainable design. We transform waste wood into ink to facilitate the first-ever 3D printing of recyclable wood structures, and we also 3D print material efficient origami designs for the first time using a brittle material. Natural wood has long been essential in construction and furniture but traditionally wood shaping has relied on subtractive manufacturing, which leads to substantial wood waste, raising critical sustainability concerns. Herein we extract lignin and cellulose from waste wood to formulate a water-based ink that facilitates the 3D printing of wood. The printed structures, after heat treatment, closely mimic natural wood’s properties, including aesthetics and mechanical characteristics. This method also allows for incorporating reinforcements, such as natural fibers. Adding natural fibers substantially improves the mechanical properties of 3D-printed wood. iii We also add fire retardants into the wood composite, which takes the structures very close to fire-safety standards, offering a sustainable pathway for the future development of fire-resistant and recyclable 3D-printed wood structures. The ancient art of origami is attractive in modern engineering for its material- efficiency. While origami-inspired metamaterials research often focuses on flexible materials, this study investigates the use of brittle materials, with the aim to change their failure mode through origami and bio-inspired soft material coatings. A ceramic based origami structure was 3D printed and coated with a biocompatible hyperelastic polymer. Mechanical tests, both experimental and numerical simulations, revealed that the origami design imparts its anisotropic behavior to the ceramic. The hyperelastic coating distributes tensile load throughout and hinders crack propagation, increasing damage tolerance and preventing catastrophic failure. This research opens the pathway to utilizing origami engineering in brittle materials. Overall, the goal is to take a step toward sustainable materials and design through additive manufacturing of bio-inspired composites.
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    Sustainable valorization of asphaltenes via flash joule heating
    (AAAS, 2022) Saadi, M.A.S.R.; Advincula, Paul A.; Thakur, Md Shajedul Hoque; Khater, Ali Zein; Saad, Shabab; Shayesteh Zeraati, Ali; Nabil, Shariful Kibria; Zinke, Aasha; Roy, Soumyabrata; Lou, Minghe; Bheemasetti, Sravani N.; Bari, Md Abdullah Al; Zheng, Yiwen; Beckham, Jacob L.; Gadhamshetty, Venkataramana; Vashisth, Aniruddh; Kibria, Md Golam; Tour, James M.; Ajayan, Pulickel M.; Rahman, Muhammad M.
    The refining process of petroleum crude oil generates asphaltenes, which poses complicated problems during the production of cleaner fuels. Following refining, asphaltenes are typically combusted for reuse as fuel or discarded into tailing ponds and landfills, leading to economic and environmental disruption. Here, we show that low-value asphaltenes can be converted into a high-value carbon allotrope, asphaltene-derived flash graphene (AFG), via the flash joule heating (FJH) process. After successful conversion, we develop nanocomposites by dispersing AFG into a polymer effectively, which have superior mechanical, thermal, and corrosion-resistant properties compared to the bare polymer. In addition, the life cycle and technoeconomic analysis show that the FJH process leads to reduced environmental impact compared to the traditional processing of asphaltene and lower production cost compared to other FJH precursors. Thus, our work suggests an alternative pathway to the existing asphaltene processing that directs toward a higher value stream while sequestering downstream emissions from the processing.
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    Three-dimensional printing of wood
    (AAAS, 2024) Thakur, Md Shajedul Hoque; Shi, Chen; Kearney, Logan T.; Saadi, M. A. S. R.; Meyer, Matthew D.; Naskar, Amit K.; Ajayan, Pulickel M.; Rahman, Muhammad M.
    Natural wood has served as a foundational material for buildings, furniture, and architectural structures for millennia, typically shaped through subtractive manufacturing techniques. However, this process often generates substantial wood waste, leading to material inefficiency and increased production costs. A potential opportunity arises if complex wood structures can be created through additive processes. Here, we demonstrate an additive-free, water-based ink made of lignin and cellulose, the primary building blocks of natural wood, that can be used to three-dimensional (3D) print architecturally designed wood structures via direct ink writing. The resulting printed structures, after heat treatment, closely resemble the visual, textural, olfactory, and macro-anisotropic properties, including mechanical properties, of natural wood. Our results pave the way for 3D-printed wooden construction with a sustainable pathway to upcycle/recycle natural wood.