An official website of the United States government
Abstract Extrusion 3D‐printing of biopolymers and natural fiber‐based biocomposites enables the fabrication of complex structures, ranging from implants' scaffolds to eco‐friendly structural materials. However, conventional polymer extrusion requires high energy consumption to reduce viscosity, and natural fiber reinforcement often requires harsh chemical treatments to improve adhesion. We address these challenges by introducing a sustainable framework to fabricate natural biocomposites usingChlorella vulgarismicroalgae as the matrix. Through bioink optimization and process refinement, we produced lightweight, multifunctional materials with hierarchical architectures. Infrared spectroscopy analysis reveals that hydrogen bonding plays a critical role in the binding and reinforcement ofChlorellacells by hydroxyethyl cellulose (HEC). As water content decreases, the hydrogen bonding network evolves from water‐mediated interactions to direct hydrogen bonds between HEC andChlorella, enhancing the mechanical properties. A controlled dehydration process maintains continuous microalgae morphology, preventing cracking. The resulting biocomposites exhibit a bending stiffness of 1.6 GPa and isotropic heat transfer and thermal conductivity of 0.10 W/mK at room temperature, demonstrating effective thermal insulation. These characteristics makeChlorellabiocomposites promising candidates for applications requiring both structural performance and thermal insulation, offering a sustainable alternative to conventional materials in response to growing environmental demands.
more »
« less
Application of Finite Element Method for Mechanical Characterization of Wood and Reconstituted Lignocellulosic-Based Composites – A Review
Performance evaluations of wood and other lignocellulosic-based composites involve complex scenarios of several factors such as material heterogeneity and geometry that often leads to complicated, expensive, and time-consuming experimental procedures. Hence, the application of computational modeling and simulation is desirable to mitigate these biocomposites’ performance testing challenges. This review paper, therefore, presents an outlook on the finite element method (FEM) application in probing performance characteristics of wood and solid wood-based composites as well as reconstituted wood and other lignocellulosic-based composites. Notwithstanding the complex nature of wood and other lignocellulosic biomass, the feasibility of FEM application in characterizing their performances has been favorably demonstrated. Going forward, broader applications of FEM combined with the design of experiments would further establish developing protocols. More exploration of FEM-based parametric and optimization studies would facilitate comprehensive, cost-efficient, and swift biocomposites design and performance optimization processes thereby enhancing their acceptance and implementation in target applications.
more »
« less
- Award ID(s):
- 2119809
- PAR ID:
- 10426504
- Date Published:
- Journal Name:
- Recent Progress in Materials
- Volume:
- 05
- Issue:
- 01
- ISSN:
- 2689-5846
- Page Range / eLocation ID:
- 1 to 37
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
The application of Materials Informatics to polymer nanocomposites would result in faster development and commercial implementation of these promising materials, particularly in applications requiring a unique combination of properties. This chapter focuses on a new data resource for nanocomposites — NanoMine — and the tools, models, and algorithms that support data-driven materials design. The chapter begins with a brief introduction to NanoMine, including the data structure and tools available. Critical to the ability to design nanocomposites, however, is developing robust structure–property–processing (s–p–p) relationships. Central to this development is the choice of appropriate microstructure characterization and reconstruction (MCR) techniques that capture a complex morphology and ultimately build statistically equivalent reconstructed composites for accurate modeling of properties. A wide range of MCR techniques is reviewed followed by an introduction of feature selection and feature extraction techniques to identify the most significant microstructure features for dimension reduction. This is then followed by examples of using a descriptor-based representation to create processing–structure (p–s) and structure–property (s–p) relationships for use in design. To overcome the difficulty in modeling the interphase region surrounding nanofillers, an adaptive sampling approach is presented to inversely determine the inter-phase properties based on both FEM simulations and physical experiment data of bulk properties. Finally, a case study for nanodielectrics in a capacitor is introduced to demonstrate the integration of the p–s and s–p relationships to develop optimized materials for achieving multiple desired properties.more » « less
-
The utilization of multifunctional composite materials presents significant advantages in terms of system efficiency, cost-effectiveness, and miniaturization, making them highly valuable for a wide range of industrial applications. One approach to harness the multifunctionality of carbon fiber reinforced polymer (CFRP) is to integrate it with a secondary material to form a hybrid composite. In our previous research, we explored the use of carbonaceous material derived from coconut shells as a sustainable alternative to inorganic fillers, aiming to enhance the out-of-plane mechanical performance of CFRP. In this study, our focus is to investigate the influence of carbonized coconut shell particles on the non-structural properties of CFRP, specifically electromagnetic interference (EMI) shielding, thermal stability, and water absorption resistance. The carbonized material was prepared by thermal processing at 400 °C. Varying proportions of carbonized material, ranging from 1% to 5% by weight, were thoroughly mixed with epoxy resin to form the matrix used for impregnating woven carbon fabric with a volume fraction of 29%. Through measurements of scattering parameters, we found that the hybrid composites with particle loadings up to 3% exhibited EMI shielding effectiveness suitable for industrial applications. Also, incorporating low concentrations of carbonized particle to CFRP enhances the thermal stability of hybrid CFRP composites. However, the inclusion of carbonized particle to CFRP has a complex effect on the glass transition temperature. Even so, the hybrid composite with 2% particle loading exhibits the highest glass transition temperature and lowest damping factor among the tested variations. Furthermore, when subjected to a 7-day water immersion test, hybrid composites with 3% or less amount of carbonized particle showed the least water absorption. The favorable outcome can be attributed to good interfacial bonding at the matrix/fiber interface. Conversely, at higher particle concentrations, aggregation of particles and formation of interfacial and internal pores was observed, ultimately resulting in deteriorated measured properties. The improved non-structural functionalities observed in these biocomposites suggest the potential for a more sustainable and cost-effective alternative to their inorganic-based counterparts. This advancement in multifunctional composites could pave the way for enhanced applications of biocomposites in various industries.more » « less
-
An increasing desire for higher application temperatures and complex geometries for metallic materials has spurred significant development in additive manufacturing (AM) of metal-ceramic composites; however, limited process-microstructure-properties relationships exist for these materials and processing strategies. Herein we investigate the processing window and high-temperature oxidation performance of an in situ reactive, oxidation-resistant titanium metal-matrix composite reinforced with boron nitride (BN) and boron carbide (B4C) via selective laser melting (SLM) to understand the effects of processing parameters on the in situ reactive characteristics and their effects on build reliability and high-temperature oxidation performance. SLM processing required a 50% decrease in overall energy density relative to titanium's optimal parameters to avoid processing failure due to the high in situ reactivity and exothermic reaction between feedstock materials. A precise balance was necessary to combine decreasing the input energy to avoid cracking due to in situ reactivity while simultaneously providing enough input energy to keep the bulk density as high as possible to limit porosity that contributes to processing inconsistencies at low input energy. Process optimization resulted in composites with as high as 98.3% relative density, comparable to some of the best composites reported in the literature, and high-temperature oxidation testing revealed a 39% decrease in oxidation mass gain compared to Ti6Al4V, owing directly to ceramic reinforcement. Our results indicate that control of SLM processing parameters can yield advanced composites with enhanced properties and characteristics compared to the base material, revealing an array of design possibilities for researchers and engineers in many fields.more » « less
-
Abstract The development of electronic devices from naturally derived materials is of enormous scientific interest. Melanin, a dark protective pigment ubiquitous in living creatures, may be particularly valuable because of its ability to conduct charges both electronically and ionically. However, device applications are severely hindered by its relatively poor electrical properties. Here, the facile preparation of conductive melanin composites is reported in which melanin nanoparticles (MNPs), directly extracted from squid inks, form electrically continuous junctions by tight clustering in a poly(vinyl alcohol) (PVA) matrix. Prepared as freestanding films and patterned microstructures by a series of precipitation, dry casting, and post‐thermal annealing steps, the percolated composites show electrical conductivities as high as 1.17 ± 0.13 S cm−1at room temperature, which is the best performance yet obtained with biologically‐derived nanoparticles. Furthermore, the biodegradability of the MNP/PVA composites is confirmed through appetitive ingestion byZophobas morioslarvae (superworms). This discovery for preparing versatile biocomposites suggests new opportunities in functional material selections for the emerging applications of implantable, edible, green bioelectronics.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.21926/rpm.2301003
