UMaine research brings sustainable packaging hands-on activity to middle school curriculums
A recent publication by Bangor, Maine middle school teacher & UMaine alum, Tracy N. Vassiliev, and University of Maine researchers, Dr. Douglas J. Gardner and Dr. David J. Neivandt was published in Science Activities on May 21, 2024. This article explores an innovative way to teach students about next-generation sustainable science. This project challenges students to a lab-based project that can be done in any classroom. Students are tasked with measuring the effect of nanocellulose composite films on water permeability. After gathering and analyzing their data, students learn to effectively communicate their research findings by writing about their conclusions, findings, results, and outlining their pre-lab procedures.
Abstract
This STEM research project asks middle school or high school students to work towards creating ecologically friendly packaging. Packaging that can be composted instead of thrown away and collected in landfills and oceans like plastics. This inquiry uses nanocellulose and focuses on water permeability. The fibers of nanocellulose can be dried to make a rather strong and thin film, but due to the spaces between the fibers the film is too water permeable and therefore makes poor packaging materials on its own. Students will create nanocellulose composite films with other biodegradable materials, in an attempt to fill the inter-fiber microscopic spaces and create a new film that can be easily tested for water permeability. Students set up a straightforward science experiment with films, water, and mason jars. They will collect and graph data to determine if their nanocellulose composite films reduce water permeability compared to plain nanocellulose and how close they are to the present standard, plastic. This research is an amalgam of disciplinary core ideas like properties and states of matter, as well as a combination of science and engineering practices. It ignites students’ curiosity, provides an organic path to science fair extensions, while also helping to cultivate future scientists, engineers, and environmental activists.
An article by ASCC researchers Wenjing Sun, Dr. Islam Hafez, Dr. Barbara J.W. Cole, and Dr. Mehdi Tajvidi was published in RSC Applied Scienceson May 15, 2024. This paper shares research on the differences of two biobased, sustainable materials (mycelium and wood) and what makes them able to adhere together. The goal of this research is to better understand and develop these sustainable adhesives, with water-soluble components from mycelium being crucial in achieving effective adhesion.
Abstract
This study investigated the adhesion at the interface between mycelium and wood in detail, focusing on the evaluation of different bonding systems and the influence of hot-pressing temperature on bonding strength. The behavior of water-soluble components and their significance in this context were examined through chemical extraction experiments and analysis. The results indicated that both degraded wood veneer and surface mycelium exhibit comparable bonding strength. In addition, a significant finding of the study is that water-soluble components washed from mycelium, which exhibit a 7% higher protein content and a distinct carbohydrate composition compared to those washed from wood, are crucial in achieving effective bonding. Notably, proteins and high-molecular-weight carbohydrates are identified as key factors responsible for the favorable bonding behavior observed with mycelium. These findings offer valuable insights for the further development of sustainable materials utilizing mycelium as a binder and emphasize the importance of manipulating the composition of water-soluble components to optimize interfacial adhesion.
ASCC research on the Kalman filter in VolturnUS-S floating wind platform
A publication by ASCC researchers Ian Ammerman, Yuskel Alkarem, Dr. Richard Kimball, Dr. Kimberly Huguenard, and Dr. Babak Hejrati was published in Wind Energyon May 16, 2024. This paper shares research on a Kalman filter, a tool used to monitor and control strategies for floating offshore wind turbines in real-time. The goal of this research is to better understand active floating offshore wind turbines on the open ocean in order to further develop floating offshore wind technologies, working towards a more sustainable future for energy in Maine.
Abstract
To enable real-time monitoring and control strategies for floating offshore wind turbines, accurate information about the state of the system is needed. This paper details the application of a Kalman filter to the UMaine VolturnUS-S floating wind platform to provide accurate state estimates in real time using minimal system measurements. The midfidelity nonlinear simulation tool OpenFAST was used to generate the underlying linear state-space model for the Kalman filter. This linear model and its limitations are demonstrated through comparison with experimental data collected on a 1:70 froude-scaled model of the floating platform and tower. Using a selection of five measurements from the real system, a Kalman filter was developed to provide estimates for the remaining system states and measurements. These estimates were then validated against the experimental values collected from testing of the scale model. Validation of the Kalman filter produced accurate estimates of surge, heave, and tower base bending moment, measurements of which were not available to the Kalman filter. Performance of the Kalman filter was tested and validated over a range of sea conditions from rated wind speed to storm events and demonstrated robustness in the Kalman filter to maintain accuracy across all operating conditions despite significant error in the underlying linear model for extreme conditions.
Cellulose nanofibers (CNFs) have been widely studied for their reinforcing potential in high-performance composites. While there are numerous publications on CNF-reinforced composites in a variety of polymer matrices, few have considered the recyclability of such thermoplastic composites and whether the incorporation of CNFs deteriorates or improves their performance upon reprocessing. In this study, two thermoplastic resins, poly(lactic acid) (PLA), and glycol-modified polyethylene terephthalate (PETg), were prepared with CNF reinforcement and thermomechanically recycled to investigate the effect of CNF inclusion on the composite properties after reprocessing as well as their effect on the composites’ number of useful life cycles. Changes in mechanical, thermal, rheological, molecular, and microstructural properties of the composites and/or base resins were monitored as a function of cycle numbers. As is typical, the polymers’ molecular weight and mechanical performance deteriorated with continued processing. However, the addition of spray dried CNF was found to better maintain the mechanical performance of both polymers throughout multiple recycling steps as compared to neat samples. For example, the tensile strength of PETg with 20 wt% CNF after 6 processing cycles was found to exceed that of virgin neat PETg, and higher loadings of CNF were found to preserve a higher yield strength during multiple rounds of reprocessing compared to PETg composites with lower CNF loadings. Ultimately this study indicates that the addition of CNF to some thermoplastic materials can increase both their sustainability by offsetting the use of high-embodied energy resins and their circularity by enabling performance retention over more use cycles.
The novel hollow-magnetite (HFO)/MXene nanohybrids with coral-like structure were successfully prepared via templating and electrostatic self-assembly techniques for electromagnetic (EM) wave adsorption application. The unique coral-like structure of the prepared HFO/MXene hybrids was characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). When mass ratio of HFO to MXene is 2:1, the maximum effective absorption bandwidth (EABmax) of HFO/MXene hybrids is able to reach 5.36 GHz. Moreover, when mass ratio of HFO to MXene is 1:1, the minimum reflection loss (RLmin) even achieves −42.48 dB with a thickness of 3.1 mm. The excellent EM absorption performance of HFO/MXene hybrids is mainly due to the ideal impedance matching and synergistic effect of magnetic loss and dielectric loss caused by unique coral-like structure. This work provides unexplored areas in the design of the spatial structure of MXene for microwave absorption.
Advanced Structures & Composites Center