Dynamic Material Research Articles

A Deterministic Model to Predict Tacticity Changes During Controlled Degradation of Polypropylene

Controlled degradation of polypropylene (CPP) converts high-molecular-weight (Mw) polypropylene (PP) to lower Mw PP using peroxide-induced degradation. A deterministic model is developed to predict tacticity changes in isotactic PP. The model determines instantaneous rates of defective-pentad formation and tracks accumulation of these pentads using dynamic material balances. The model relies on the assumption that lifetimes of polymeric radicals are short compared to extruder residence times. Model predictions agree with previous Monte Carlo simulations that require long simulation times. Two versions of the model are proposed: one assumes that radical migration, also called chain walking, occurs via 1–6 isomerization and one assumes 1–8 isomerization. Chain-transfer-to-polymer and chain-walking parameters are estimated using 13C NMR data obtained using initiator levels between 0.006 and 0.52 wt%. Both 1–6 and 1–8 isomerization models result in better fit to the data.

Critical material requirements and recycling opportunities for US wind and solar power generation

AbstractThe deployment of renewable energy generation technologies, driven primarily by concerns over catastrophic climate change, is expected to increase rapidly in the United States. Rapid increases in the deployment of wind and solar energy will translate to increases in critical material requirements, causing concern that demand could outstrip supply, leading to mineral price volatility and potentially slowing the energy transition. This study presents a detailed demand‐side model for wind and solar in the United States using dynamic material flow analysis to calculate the requirements for 15 elements: Cr, Zn, Ga, Se, Mo, Ag, Cd, In, Sn, Te, Pr, Nd, Tb, Dy, and Pb. Results show that transitioning to a completely decarbonized US energy system by 2050 could require a five‐to‐sevenfold increase in critical material flow‐into‐use compared with business as usual (BAU), with some materials requiring much larger increases. Rare earth elements (REEs) could require 60–300 times greater material flows into the US power sector in 2050 than in 2021, representing 13%–49% of the total global REE supply. Te requirements for reaching net zero by 2050 could exceed current supply, posing challenges for widespread deployment of cadmium‐telluride solar. We also investigate several strategies for reducing material requirements, including closed‐loop recycling, material intensity reduction, and changing market share of subtechnologies (e.g., using crystalline silicon solar panels instead of cadmium telluride). Although these strategies can significantly reduce critical material requirements by up to 40% on average, aggressive decarbonization will still require a substantial amount of critical material.

Inter-coat protein loading of active ingredients into Tobacco mild green mosaic virus through partial dissociation and reassembly of the virion

Chemical pesticide delivery is a fundamental aspect of agriculture. However, the extensive use of pesticides severely endangers the ecosystem because they accumulate on crops, in soil, as well as in drinking and groundwater. New frontiers in nano-engineering have opened the door for precision agriculture. We introduced Tobacco mild green mosaic virus (TMGMV) as a viable delivery platform with a high aspect ratio and favorable soil mobility. In this work, we assess the use of TMGMV as a chemical nanocarrier for agriculturally relevant cargo. While plant viruses are usually portrayed as rigid/solid structures, these are “dynamic materials,” and they “breathe” in solution in response to careful adjustment of pH or bathing media [e.g., addition of solvent such as dimethyl sulfoxide (DMSO)]. Through this process, coat proteins (CPs) partially dissociate leading to swelling of the nucleoprotein complexes—allowing for the infusion of active ingredients (AI), such as pesticides [e.g., fluopyram (FLP), clothianidin (CTD), rifampicin (RIF), and ivermectin (IVM)] into the macromolecular structure. We developed a “breathing” method that facilitates inter-coat protein cargo loading, resulting in up to ~ 1000 AIs per virion. This is of significance since in the agricultural setting, there is a need to develop nanoparticle delivery strategies where the AI is not chemically altered, consequently avoiding the need for regulatory and registration processes of new compounds. This work highlights the potential of TMGMV as a pesticide nanocarrier in precision farming applications; the developed methods likely would be applicable to other protein-based nanoparticle systems.

Dynamic Chalcogen Squares for Material and Topological Control over Macromolecules

AbstractHerein we introduce chalcogen squares via selenadiazole motifs as a new class of dynamic supramolecular bonding interactions for the modification and control of soft matter materials. We showcase selenadiazole motifs in supramolecular networks of varying primary chain length prepared through polymerization using tandem step‐growth/Passerini multicomponent reactions (MCRs). Compared to controls lacking the selenadiazole motif, these networks display increased glass transition temperatures and moduli due to the chalcogen bonding linkages formed between chains. These elastomeric networks were shown to autonomously heal at room temperature, retaining up to 83 % of the ultimate tensile strength. Lastly, we use post‐polymerization modification via the Biginelli MCR to add selenadiazole motifs to narrowly dispersed polymers for controlled topology in solution. Chalcogen squares via selenadiazoles introduce an exciting exchange mechanism to the realm of dynamic materials.

Ensuring the sustainable supply of semiconductor material: A case of germanium in China

The semiconductor industry relies on the sustainable supply of critical mineral resources, such as Germanium (Ge), a key metal used in making electronics, fiber cables and solar cells. However, since Ge is a companion element, its primary production is constrained by the availability of host minerals such as zinc and coal. As such, its recycling is challenging since both recycling networks and technologies are still in its early infancy. There are increasing concerns on how to meet with the future demand for Ge due to its limited supply. This study aims to uncover the metabolic characteristics of the Ge cycle in China for the period of 2002–2021 from a whole life cycle perspective by employing a dynamic material flow analysis. The results show that China's demand for Ge had increased from 19.16 tons in 2002 to 85.87 tons in 2021. Fiber cables and infrared optical instruments consumed the most Ge resource, accounting for 54.59% and 36.76% of the total Ge consumption, respectively. The in-use Ge stock had increased more than 40 folds, implying a substantial potential for future recycling. The majority of Ge was extracted from coal ash and zinc concentrates, with figures of 1086.92 tons and 585.27 tons respectively, while only 13.45 tons of Ge were recovered from those end-of-life products. Furthermore, the Ge loss reached 1586.31 tons at the production stage. The Ge stock in those intermediate products has gradually decreased. The cumulative Ge export amount contained in various products was 655.64 tons, mainly dominated by intermediate products, while the share of final products increased in recent years. Based on these findings, several policy recommendations are proposed, including improving Ge production efficiency and expanding Ge supply sources, establishing a comprehensive Ge recycling system, and upgrading the entire Ge industrial chain. These policies can help better cope with the challenges that the global semiconductor supply chain is facing.

Dynamic Chalcogen Squares for Material and Topological Control over Macromolecules.

Herein we introduce chalcogen squares via selenadiazole motifs as a new class of dynamic supramolecular bonding interactions for the modification and control of soft matter materials. We showcase selenadiazole motifs in supramolecular networks of varying primary chain length prepared through polymerization using tandem step-growth/Passerini multicomponent reactions (MCRs). Compared to controls lacking the selenadiazole motif, these networks display increased glass transition temperatures and moduli due to the chalcogen bonding linkages formed between chains. These elastomeric networks were shown to autonomously heal at room temperature, retaining up to 83 % of the ultimate tensile strength. Lastly, we use post-polymerization modification via the Biginelli MCR to add selenadiazole motifs to narrowly dispersed polymers for controlled topology in solution. Chalcogen squares via selenadiazoles introduce an exciting exchange mechanism to the realm of dynamic materials.

Fundamental limits of dynamic phase change materials

To accommodate societal electrification and decarbonization, renewable energy resources continue to expand their share of the global energy market. The intermittency of renewable energy technologies as well as the high power density of modern electrified platforms necessitates the need for both efficient thermal management and high-density thermal storage. Phase change materials are a promising passive thermal energy storage solution. However, difficulties with efficient system implementation stemming from the inherent melt pool formation hinder their potential. We develop an innovative strategy, termed dynamic phase change material “dynPCM,” to address this thermal transport issue by ensuring a constant, thin, melt layer. We analyze the fundamental limits of dynPCMs, characterize the peak achievable heat flux and energy/power densities, estimate the power consumption of dynPCM systems, and investigate the fundamental physics which govern dynPCM behavior. We show that dynPCM can eliminate the classical trade-off seen between energy density and power density and achieve ultrahigh heat fluxes, ∼105 W/cm2, with heat flux-to-required power ratios as high as ∼107. We also demonstrate achievable power densities as high as ∼100 W/cm3 at energy densities as high as ∼10 kJ/cm3. Throughout this work, we develop a methodology to evaluate the operating limits, enabling adaptation of the dynPCM system concept to a variety of applications and industries.

The Effect of the Project-Based Learning (PjBL) Model based on an Integrated STEM Approach with Entrepreneurial Character on Students' Creative Thinking Ability

This research aims to measure students' creative thinking abilities using the Project-Based Learning (PjBL) model based on an integrated STEM approach with entrepreneurial character in dynamic electrical material. This type of research is quasi-experimental with a none-equivalent pre-test and post-test control group design research model. The population in this study was all students in class XII phase F, with a total of 8 classes. The sampling was taken using cluster random sampling. Class F4 is an experimental class with 35 people, and class F3 is a control class with 35 people. The experimental class implemented STEM-based PjBL integrated entrepreneurial character and the control class with conventional learning. The instrument used was a 4 question description test to measure creative thinking. Based on the t-test, it was found that the initial abilities in both classes were the same in terms of creative thinking skills. The average post-test score for the experimental class and control class. Based on the t-test, there is a significant difference, which means there is an influence of STEM-based PjBL integrated with entrepreneurial character on creative thinking skills.

Influence of key design variables on dynamic material properties of iron tailing porous concrete under impact loading

Iron tailing porous concrete (ITPC) is a new foamed concrete material that using iron ore tailing powder to partially replace the cement. Previous investigations on ITPC primarily focused on its mechanical properties under static loads or low strain rate conditions, leaving a significant gap in its impact resistance performance at high strain rates. This study employed the split Hopkinson pressure bar (SHPB) to test ITPC specimens under impact loading with strain rate around 120 s−1. Density, water-binder (W/B) ratio, iron tailing powder content, polypropylene fiber length and content were taken as key design variables to prepare the ITPC specimens with different mix ratios and study their effects on the dynamic material properties of ITPC. Specifically, the failure modes, stress-strain relations, elastic moduli, compressive strengths and energy dissipation densities of the ITPC specimens with various design variables were recorded and compared. The test results indicate that the material density, fiber length and content have strong influences on the impact failure modes of ITPC. The elastic modulus, compressive strength and energy dissipation density of ITPC exhibit exponential growth with the material density. These parameters, however, show an initial growth followed by a decrease with the rising W/B ratio, fiber length and fiber content, and they reach the peak values at around 0.70, 9 mm and 2.0%, respectively. Moreover, the iron tailing powder content of 25% is recommended for ITPC for maintaining good impact resistance.

Dynamic Reversible Full-Color Piezochromic Fluorogens Featuring Through-Space Charge-Transfer Thermally Activated Delayed Fluorescence and their Application as X-Ray Imaging Scintillators.

Thermally activated delayed fluorescence (TADF) emitters featuring through-space charge transfer (TSCT) can be excellent candidates for piezochromic luminescent (PCL) materials due to their structural dynamics. Spatial donor-acceptor (D-A) stacking arrangements enable the modulation of inter- and intramolecular D-A interactions, as well as spatial charge transfer states, under varying pressure conditions. Herein, we demonstrate an effective approach toward dynamic reversible full-color PCL materials with TSCT-TADF characteristics. Their single crystals exhibit a full-color-gamut PCL process spanning a range of 170 nm. Moreover, the TSCT-TADF-PCL emitters display a unity photoluminescence quantum yield, and show promising application in X-ray scintillator imaging.

Modulation of the Dynamics of a Two-Dimensional Interweaving Metal-Organic Framework through Induced Hydrogen Bonding.

Inducing, understanding, and controlling the flexibility in metal-organic frameworks (MOFs) are of utmost interest due to the potential applications of dynamic materials in gas-related technologies. Herein, we report the synthesis of two isostructural two-dimensional (2D) interweaving zinc(II) MOFs, TMU-27 [Zn(bpipa)(bdc)] and TMU-27-NH2 [Zn(bpipa)(NH2-bdc)], based on N,N'-bis-4-pyridyl-isophthalamide (bpipa) and 1,4-benzenedicarboxylate (bdc) or 2-amino-1,4-benzenedicarboxylate (NH2-bdc), respectively. These frameworks differ only by the substitution at the meta-position of their respective bdc groups: an H atom in TMU-27 vs an NH2 group in TMU-27-NH2. This difference strongly influences their respective responses to external stimuli, since we observed that the structure of TMU-27 changed due to desolvation and adsorption, whereas TMU-27-NH2 remained rigid. Using single-crystal X-ray diffraction and CO2-sorption measurements, we discovered that upon CO2 sorption, TMU-27 undergoes a transition from a closed-pore phase to an open-pore phase. In contrast, we attributed the rigidification in TMU-27-NH2 to intermolecular hydrogen bonding between interweaving layers, namely, between the H atoms from the bdc-amino groups and the O atoms from the bpipa-amide groups within these layers. Additionally, by using scanning electron microscopy to monitor the CO2 adsorption and desorption in TMU-27, we were able to establish a correlation between the crystal size of this MOF and its transformation pressure.

Application of the Problem Based Learning Model Combined with Think Pair Share to Improve Conceptual Understanding and Applied Physics Learning Outcomes for Electrical Engineering Students

This research aims to improve understanding of physics concepts and learning outcomes of Electrical Engineering students at the Politeknik Muhammadiyah Tegal by using the Problem Based Learning model combined with Think Pair Share on dynamic electrical material. The research instruments used were lecturer and student observation sheets, worksheets and test question sheets. In the analysis of students' conceptual understanding, an increase of 8.58% was obtained from cycle I to cycle II. Meanwhile, in the analysis of student learning outcomes in cycle I, the number of students who passed was 61.76%, and in cycle II the number of students who passed was 82.35%. The results of this research show that the application of the Problem Based Learning model combined with Think Pair Share can improve students' understanding of concepts and learning outcomes.

Dynamic Fluorescence Materials Based on Naphthalimide-Functionalized Silica Aerogels and Applications in Advanced Information Encryption.

With the progress of forgery and decryption, the traditional encryption technology is apparent not enough, which strongly requires the development of advanced multidimensional encryption strategies and technologies. Photo-stimuli responsive fluorescent materials are promising as candidate materials for advanced information encryption. Here, we have reported new photo-stimuli responsive materials by encapsulating photochromic molecules spiropyrans (SPs) into naphthalimide-functionalized silica aerogels. By introducing different modification groups (dimethylamino) into 1,8-naphthalimide, we obtained two kinds of silica aerogels that emit blue and green colors. The naphthalimide-functionalized silica aerogels/dye composite exhibits a blue (dimethylamino-modified naphthalimide-functionalized silica aerogel showing green) emission from naphthalimide of silica aerogels at 450 nm (520 nm) and a red emission around 650 nm of SP. Under exposure to ultraviolet light, SP gradually transformed into the merocyanine (MC) form, and a strong absorption band appeared near 540 nm. At that time, the fluorescence resonance energy-transfer (FRET) process occurred between naphthalimide and the MC isomer. As the irradiation time is extended, the fluorescence color changes continuously from blue (green) to red through the FRET process. Using the time dependence of fluorescence, dynamic encryption patterns and multiple codes were successfully developed based on these functionalized silica aerogels. This work has provided important guidance for designing advanced information encryption materials.

Time-dependent dynamic photoluminescence of Eu3+-activated MgGa2O4 for advanced luminescence anticounterfeiting

In the modern society, luminescence anticounterfeiting plays a key part in information transmission. Nevertheless, most of the present luminescence anticounterfeiting logos are based on static photoluminescence (PL), which is easily counterfeited by substitutes. In this work, a time-dependent dynamic PL material, MgGa2O4:Eu3+, was successfully prepared. Under a portable 254 nm ultraviolet (UV) lamp irradiation, the PL color of the materials dynamically changes from red to pink to blue. After ceasing the UV irradiation, the blue persistent luminescence (PersL) with different afterglow time and bright was observed. The investigation reveals that the dynamic PL derives from the diverse time-dependent intensities of the MgGa2O4 trap-related emission and the Eu3+ 4f-4f transitions, and the Eu3+ dopant can introduce more traps into the host and consequently manipulate the dynamic PL and the PersL performances. The dynamic luminescent anticounterfeiting properties of the prepared material MgGa2O4:Eu3+ was investigated by a powder filling method, demonstrating the potential for applications in advanced anticounterfeiting.

Development of A Physics-Based E-Module Iman Taqwa-Loading CTL on Dynamic Fluid Materials

The CTL model is a model that can help teachers motivate students to make connections between the content of the material and real-life situations, and this model requires teachers to create alternative teaching materials as a guide. The development of good teaching materials that combine religious values with science. Therefore, researchers are interested in developing this e-module. This research aims to determine the validity of the product being developed, namely a physics e-module based on CTL containing implications for dynamic fluid material, and to find out how students respond to the product the researcher developed. This research is development research, and the development model used is the ADDIE development model, which consists of five stages. However, this research only reached the development stage because research aimed to develop and produce valid teaching materials based on validator assessments, and at each stage of this model, there is evaluation and revision. First, the researchers analyzed the curriculum, needs, and materials. Then, they design it, the initial design stage for developing a product. Next, the development is the stage where the previously prepared design realizes the product design. Validators consist of two physics lecturers and one physics teacher. The development trial subjects were 34 class XII, IPA 1, MAN 1, and HST students. The product validation results from material experts were 81%, and from media experts were 82%, where both of these figures are included in the very valid criteria. The results of the student response test on the product being developed were 85%, which met very good criteria. Based on these results, the physics e-module based on CTL contains imprints on dynamic fluid material is declared valid and very good. Implications development is helping teach physics in religion and dynamic fluid materials. Implications of research for helping increase learning module fluid dynamics include religion (Islamic).

Exploring Emergent Properties in Enzymatic Reaction Networks: Design and Control of Dynamic Functional Systems.

The intricate and complex features of enzymatic reaction networks (ERNs) play a key role in the emergence and sustenance of life. Constructing such networks in vitro enables stepwise build up in complexity and introduces the opportunity to control enzymatic activity using physicochemical stimuli. Rational design and modulation of network motifs enable the engineering of artificial systems with emergent functionalities. Such functional systems are useful for a variety of reasons such as creating new-to-nature dynamic materials, producing value-added chemicals, constructing metabolic modules for synthetic cells, and even enabling molecular computation. In this review, we offer insights into the chemical characteristics of ERNs while also delving into their potential applications and associated challenges.

Two-Phase Adaptive Kriging Model Based Importance Sampling Method for Estimating Time-Dependent Failure Probability

To improve the computational efficiency of the time-dependent failure probability (TDFP) to system with dynamic loads, materials degeneration and other time-varying factors, a two-phase adaptive Kriging model-based importance sampling (IS) method is proposed. The main contribution of this article is that a single Kriging model is established and adaptively refined to gradually approach the optimal IS probability density function (PDF) and estimate TDFP in two sequential phases. In the first phase, a generally approximate IS PDF is constructed by Kriging model based on its prediction characteristic and subsequently updated until convergence. Then, a simple rejection sampling technique is used to robustly generate IS samples for the estimation of TDFP. In the second phase, current Kriging model is subsequently refined for accurately identifying the classification of the IS samples generated in the last phase. Finally, the TDFP can be estimated using the products obtained in the above two phases. As the IS PDF established by Kriging model is used for directly approximating the optimal one, the proposed method has the capacity to deal with the complicated problem containing multiple failure regions. Additionally, since IS procedure can dramatically improve the sampling efficiency, the proposed method is an effective technique to the time-consuming TDFP analysis problems.

Recent progress in shape memory alloy reinforced composites: A review of the properties, production, mechanisms involved and functional applications

SMAs are unique materials characterized by their 'Superelasticity' (pseudoelasticity) and 'Shape Memory Effect.' Its unusual properties have led to its use in various fields of science. However, its mechanical advantages are not fully exploited due to its price and lack of data. SMAs are not adopted widely in industries due to the scarcity of manufacturing knowledge. Potential uses for them came in the form of reinforcements in composites. The rapidly growing field focuses on the incorporation of Shape Memory Alloy wires, ribbons, fibres, and powders in polymer or metal matrices. Its effect on static and dynamic material properties is also of great importance, especially when it comes to incorporating it into modern-day applications. Hence, this paper deals with a summary of all those properties. Furthermore, the article touches upon the possible applications of Shape Memory Alloy Reinforced Composites in the real world and their potential scope in the future.

Evaluation of silicon and indium gallium arsenide photodiodes as direct timing detectors for pulsed x-ray systems.

Benchtop pulsed x-ray systems are commonly used to record dynamic material data on the order of nanoseconds, but pulse timing is often difficult to accurately determine. This study demonstrates that commercially available photodiodes can be used effectively for direct x-ray pulse detection without the need for visible light scintillators. X-ray pulses from four commercially available flash x-ray systems were quantified using one silicon and two indium gallium arsenide (InGaAs) photodiodes. The measured InGaAs pulse durations were strongly dependent on radiation dose in the non-linear operating regime, so the photodiodes were shielded to operate below the 2.5V non-linear regime threshold. The average pulse duration and pulse arrival time jitter of the photodiodes for each x-ray source were within several nanoseconds with the exception of two sets of measurements that were affected by low instrument sensitivity and electrical noise. These results show that InGaAs photodiodes can be used as effective and repeatable stand-alone timing diagnostics for x-ray pulses as short as 20ns or less.

Mapping the evolution of manganese flows and stocks in China from 2000 to 2021

Manganese is a strategic metal that has been widely applied in the steelmaking industry and the emerging energy batteries industry. China is the largest manganese importer and consumer, but the critical features of its manganese metabolisms, including its supply and demand, trade, and waste management, remain unclear. By applying dynamic material flow analysis (DMFA) method, this research investigates the evolution of China’s anthropogenic manganese flows and stocks during the period of 2000 to 2021. We found that the demand for manganese had increased almost tenfold in China from 2000 to 2021, mainly used for steelmaking, while the surging demand for manganese in energy batteries had gradually increased. However, China highly relied on importing manganese concentrates due to its limited manganese resources. The cumulative in-use manganese stocks also increased by tenfold and reached approximately 168 million tons (Mt). In addition, manganese flow from the end-of-life (EoL) final products reached 12 Mt in 2021, but few of them were recycled, implying a huge recycling potential. These findings provide valuable insights to prepare more appropriate manganese resource management policies, such as improving domestic mining technologies, enhancing manganese recycling, and diversifying the supply of manganese resources, so that the overall manganese resource efficiency can be improved.