Materials Science Concepts Research Articles

Unraveling Interdiffusion Phenomena and the Role of Nanoscale Diffusion Barriers in the Copper-Gold System.

Diffusion is one of the most fundamental concepts in materials science, playing a pivotal role in materials synthesis, forming, and degradation. Of particular importance is solid state interdiffusion of metals which defines the usable parameter space for material combinations in the form of alloys. This parameter space can be explored on the macroscopic scale by using diffusion couples. However, this method reaches its limit when going to low temperatures, small scales, and when testing ultrathin diffusion barriers. Therefore, this work transfers the principle of the diffusion couples to small scales by using core-shell nanowires and in situ heating. This allows us to delve into the interdiffusion dynamics of copper and gold, revealing the interplay between diffusion and the disorder-order phase transition. Our in situ TEM experiments in combination with chemical mapping reveal the interdiffusion coefficients of Cu and Au at low temperatures and highlight the impact of ordering processes on the diffusion behavior. The formation of ordered domains within the solid-solution is examined using high-resolution imaging and nanodiffraction including strain mapping. In addition, we examine the effectiveness of ultrathin Al2O3 barrier layers to control interdiffusion of the diffusion couple. Our findings indicate that a 5 nm thick layer serves as an efficient diffusion barrier. This research provides valuable insights into the interdiffusion behavior of Cu and Au on the nanoscale, offering potential applications in the development of miniaturized integrated circuits and nanodevices.

Interface-Interactive Nanoarchitectonics: Solid and/or Liquid.

The methodology of nanoarchitectonics is to construct functional materials using nanounits such as atoms, molecules, and nanoobjects, just like architecting buildings. Nanoarchitectonics pursues the ultimate concept of materials science through the integration of related fields. In this review paper, under the title of interface-interactive nanoarchitectonics, several examples of structure fabrication and function development at interfaces will be discussed, highlighting the importance of architecting materials with nanoscale considerations. Two sections provide some examples at the solid and liquid surfaces. In solid interfacial environments, molecular structures can be precisely observed and analyzed with theoretical calculations. Solid surfaces are a prime site for nanoarchitectonics at the molecular level. Nanoarchitectonics of solid surfaces has the potential to pave the way for cutting-edge functionality and science based on advanced observation and analysis. Liquid surfaces are more kinetic and dynamic than solid interfaces, and their high fluidity offers many possibilities for structure fabrications by nanoarchitectonics. The latter feature has advantages in terms of freedom of interaction and diversity of components, therefore, liquid surfaces may be more suitable environments for the development of functionalities. The final section then discusses what is needed for the future of material creation in nanoarchitectonics.

In-Situ and in-Operando Li-Ion Batteries for Materials Science Education

Electrochemical energy storage systems, particularly Li-ion rechargeable batteries (LiRB), have a key role to play in fortifying US energy generation, decarbonizing the electricity sector, and limiting anthropogenic climate change. LiRBs suffer from limited lifetimes, insufficient energy densities, and fire risks, which are all materials science and engineering challenges stemming from various irreversible degradation processes occurring at nano and micro-scales. These batteries function via the reversible diffusion of Li ions from a Li-rich cathode to a Li-poor anode, each of which undergo various levels of volumetric phase changes, plastic deformation, and microcracking with each charging cycle, thereby compromising subsequent battery performance. Therefore, it is imperative to understand the nano-mechanical processes associated with LiRB degradation and predict transformative material designs that can lead to manufacturing cheaper, denser, and safer LiRBs. Such understanding and design would be instrumental to achieving the US 2050 Net Zero Goal. Additionally, the US lags 10x behind China in terms of Li battery manufacturing capability, and thus a LiRB-aware Research and Development workforce is paramount for continued US energy security. In this context, we propose a new design for in-situ and in-operando Li-ion battery research and education. This battery design will be used in a classroom/lab setting to discuss fundamental materials science concepts such as diffusion, grain-boundaries, and fracture. This activity will be used to broaden "missing millions" student participation in a crucial area of energy research at a minority serving institution.

(Invited) Recent Progress Towards Giga-Scale Sodium-Ion Batteries

Ongoing lithium-ion minerals supply chain volatility has driven price increases and supply shortages, and motivates the development and commercialization of alternative cell chemistries not dependent on those minerals.1-2 Among these alternative chemistries, sodium-ion cells offer promise due to the abundance and low cost of both sodium salts and typical electrode active species such as iron and manganese.2-3 Among sodium-ion electrode systems, Prussian blue analogues offer unique performance advantages including high C-rate charge and discharge, long cycle life, and thermal stability.4-6 Natron Energy has commercialized a unique sodium-ion cell in which each of the anode and cathode active materials are Prussian blue analogues. Products based on these cells are capable of full discharge at up to 60C, full recharge at up to 20C, and operate for tens of thousands of cycles without risk of thermal runaway. However, their energy density is limited by relatively low electrode specific capacities and cell voltage. This presentation will introduce the key materials science concepts that make Prussian blues a commercially viable materials system, as well as those that limit product performance, manufacturability, and the resulting applicable markets. In addition, Natron’s recent progress towards mass manufacturing of cells based on these materials will be summarized. This presentation will conclude with an overview of the key open scientific questions that must be answered for cost effective, giga-factory scale manufacturing of sodium-ion cells to become a reality.

Lignin, the Lignification Process, and Advanced, Lignin-Based Materials.

At a time when environmental considerations are increasingly pushing for the application of circular economy concepts in materials science, lignin stands out as an under-used but promising and environmentally benign building block. This review focuses (A) on understanding what we mean with lignin, i.e., where it can be found and how it is produced in plants, devoting particular attention to the identity of lignols (including ferulates that are instrumental for integrating lignin with cell wall polysaccharides) and to the details of their coupling reactions and (B) on providing an overview how lignin can actually be employed as a component of materials in healthcare and energy applications, finally paying specific attention to the use of lignin in the development of organic shape-memory materials.

Identifying relevant topics and their competency levels for dental materials science: a fuzzy Delphi study

BackgroundDental materials science is an important core course in undergraduate dental programs which integrates foundational concepts of chemical engineering and materials science into clinical dentistry. The present study aimed to identify relevant dental materials science topics for Malaysian undergraduate dental curricula and to determine their appropriate competency levels in terms of cognitive and psychomotor taxonomies.MethodsPotential dental materials science topics were drafted in alignment with the revised national competency statement. The list of topics was further amended after comparing it with those recommended topics in the literature. Fuzzy Delphi method was applied. Experts were selected based on the different inclusion criteria. They ranked the topics using a five-point Likert scale and recommended the appropriate cognitive and psychomotor levels. Next, fuzzy evaluation was performed. Consensus was deemed for a topic to be included if (a) the average expert agreement was ≥ 75%, (b) the d-construct threshold value for each topic was ≤ 0.2 and (c) the average fuzzy number was ≥ 0.5.ResultsSixty-two experts participated in the study. They accepted 33 out of 36 potential dental materials science topics. The average Likert score and fuzzy number ranged from 3.63 to 4.92 and 0.526 to 0.784, respectively. Furthermore, “Endodontic materials” was ranked as the most significant topic. Meanwhile, many topics required dental students to demonstrate a cognitive level of “Apply” and a psychomotor level of “Guided response”. Based on mean scores, “Impression materials” was rated as the most cognitively demanding topic, whilst “Temporary restorative materials” was the most demanding topic for psychomotor taxonomy.ConclusionThe present study has identified relevant dental materials science topics and their appropriate cognitive and psychomotor levels using the Fuzzy Delphi approach. The findings of the present study form the basis for future studies to develop measurable learning outcomes, design corresponding innovative pedagogy and propose assessment criteria for each topic.

Foreword to the focus issue: advancements of functional materials with nanoarchitectonics as post-nanotechnology concept in materials science

Foreword to the focus issue: advancements of functional materials with nanoarchitectonics as post-nanotechnology concept in materials science

Cellulose Nanofibrils Pulverized from Biomass Resources: Past, Present, and Future Perspectives

Advances in nanotechnology have changed conventional concepts in materials science. This has aloso strongly influenced natural biomass products with hierarchically built-up structures. In general, hierarchical structures in bio-based materials are built up by molecular self-assembly, followed by nanoassembly to form higher-level structures. Key to each step is the formation of interactions at each individual scale. Nature usually achieves such fabrication through a bottom-up process. However, fabrication can also be achieved through a top-down process, with various such downsizing methods now in development. This review article aims to describe trends in nanofiber technology among downsizing processes applied to cellulose as a representative biomass, ranging from fundamentals to recent techniques. The advantages of our recently developed technique, nanopulverization by aqueous counter collision, are also discussed. This method successfully decomposes interactions selectively without damaging the molecular structure, finally liberating components of various sizes into water to provide a transparent and homogeneous component–water system. As nanocellulose research is a broad area involving various fields, the cited references are limited to the scope of the author’s knowledge.

Polystyrene Laboratory Analysis: A Hands-On Experience for High School Students to Determine the Molecular Weight of Polystyrene Through Spin Casting

Hands-on learning is a staple in high school science education, as it provides students with a fast-learning curve and a great degree of field competency. However, due to the safety risks associated with high school students in university chemistry laboratory settings, high school students rarely engage in authentic hands-on chemical learning. To bridge the gap between the benefits and drawbacks, this study investigates a method to educate high school students (with no previous experience) about standard chemical laboratory practices. 98 high school students experimented throughout 2 days to determine the molecular weights and characteristics of various polystyrene samples, essential knowledge for polymer recycling. Students were split into 5 groups so that laboratory usage be organized and staggered. After laboratory safety training was administered, students created different types and concentrations of toluene-based samples and spin-casted these samples onto silicon wafers, determining thickness through ellipsometry. With the data, each group calculated molecular weight, propagated error, and wrote laboratory reports. In order to evaluate the extent of learning through this process, students were given pretraining and postexperimentation assessments with the same questions pertaining to laboratory safety, equipment usage, and materials science related topics. On average, students displayed scores 63% higher on the postexperiment assessment compared to those of the pretraining assessment. The results suggest the experience not only taught students about the various materials science concepts but also improved their laboratory logic. Therefore, our method is recommended to be implemented at the university level for motivated high school and first-year undergraduate students.

Multi-Response Modelling and Optimisation of Mechanical Properties of Al-Si Alloy Using Mixture Design of Experiment Approach

The research aims to produce, model, and optimise the mechanical properties of novel composite material through a structured multidisciplinary approach. The primary objective is to combine materials science, mechanical engineering, and statistical concepts to ensure Design for Manufacturability (DFM) from the industrial perspective. More specifically, the article is intended to determine the optimal mixture components and predictive model of Al-Si alloy with Al2O3 by accommodating multi-responses that enable DFM. The study adopted ASTM standards to prepare and test the novel composite material. Additionally, the Mixture Design of Experiment (DOE) approach was used to design the experimentation and subsequent analysis. In addition, microstructural images, Cox Response Trace plot, and Response Optimiser plot are effectively utilised to draw robust inferences. For multi-response modelling and optimisation, the composite material’s mechanical properties, like impact strength, hardness, density, and tensile strength, are considered. The study determines that innovative composite material will yield better results when Al-Alloy is 94.65 wt% and Al2O3 is 5.35 wt% from a multi-responses perspective. Further, it provides predictive models with a high level of predictability. Besides, the research shows that novel composite material has better mechanical properties from a practical perspective. The article not only provides the mechanical properties of a new class of material but also shows the effective utilisation of material science and statistical concepts to develop the novel material in a structured manner. This composite material can be used as a replacement for various parts of automobiles and aircraft. Additionally, researchers can use the article’s modelling and optimisation approach as a paradigm to create durable composite materials.

The Engineerization of Physical and Chemical Phenomena

There are a number of concepts in materials science that are only ambiguously described in the literature and/or are not completely understood [...]

Multivariate Polymer Laboratory on Synthesis of Alginate Hydrogel Beads and Analysis of Dye Loading and Release

We have developed a multivariate and multidisciplinary lab experiment on the synthesis of alginate hydrogel beads of various sizes and dye encapsulation for upper-division undergraduate and graduate students. This experiment introduces students to several common concepts in polymer chemistry, materials science, and drug delivery. The experiment series runs over two 3-h laboratories where students first synthesize alginate beads by dropwise addition of an alginate solution into aqueous CaCl2. The alginate bead size is regulated physically via the dropper opening and chemically via cross-linking ion variation, cross-linking time, and surfactant. During the second lab session, students explore the effects of bead size and solution environment on the gel’s loading capacity, encapsulation efficiency, and controlled release using a model dye. Finally, students present their results, methodology, and data analysis to the class. A report and an exam allow the students to demonstrate their knowledge. Students learn critical drug delivery concepts throughout the project, including controlling particle size, loading capacity, and encapsulation efficiency. They also acquire valuable insight into the applications of gel particles and standard techniques used in industrial and academic research. The developed lab experience includes experiments of varying difficulty and can be adapted to first- and second-year undergraduate students by simplifying the suggested laboratory procedures.

Symmetry of antiferroelectric crystals crystallized in polar point groups.

Symmetry is an essential concept in physics, chemistry and materials science. Comprehensive, authoritative and accessible symmetry theory can provide a strong impetus for the development of related materials science. Through the sustained efforts of physicists and crystallographers, researchers have mastered the relationship between structural symmetry and ferroelectricity, which demands crystallization in the 10 polar point groups. However, the symmetry requirement for antiferroelectricity is still ambiguous, and polar crystals possessing antiferroelectricity seem contradictory. This work systematically and comprehensively studies the transformation of dipole moments under symmetry operations, using accessible geometric methods and group theory. The results indicate crystals that crystallize in polar point groups 2 (C 2), m (C 1h), mm2 (C 2v), 4 (C 4), 4mm (C 4v), 3m (C 3v), 6 (C 6) and 6mm (C 6v) also possess anti-polar structure and are capable of Kittel-type antiferroelectricity. The anti-polar direction of each point group is also highlighted, which could provide a straightforward guide for antiferroelectric property measurement. Like ferroelectric crystals, antiferroelectric crystals belonging to polar point groups have great potential to become a family of important multifunctional electroactive and optical materials. This contribution refines antiferroelectric theory, will help facilitate and stimulate the discovery and rational design of novel antiferroelectric crystals, and enrich the potential functional applications of antiferroelectric materials.

A Multidisciplinary Experiment to Characterize Antifouling Biocompatible Interfaces via Quantification of Surface Protein Adsorption.

Novel biomaterial development is a rapidly growing field that is crucial because biomaterial fouling, due to rapid and irreversible protein adsorption, leads to cellular responses and potentially detrimental consequences such as surface thrombosis, biofilm formation, or inflammation. Therefore, biomaterial technology's fundamentals, like material biocompatibility, are critical in undergraduate education. Exposing undergraduate students to biomaterials and biomedical engineering through interdisciplinary experiments allows them to integrate knowledge from different fields to analyze multidisciplinary results. In this practical laboratory experiment, undergraduate students will characterize surface properties (contact and sliding angle measurements) for the antifouling polydimethylsiloxane (PDMS) polymer using a goniometer and a smartphone, as well as quantify protein adsorption on antifouling surfaces via a colorimetric assay kit to develop their understanding of antifouling surface characteristics, UV-vis spectroscopy, and colorimetric assays. The antifouling PDMS polymer is prepared by silicone oil infusion and compared to untreated control PDMS. The polymer hydrophobicity was demonstrated by static water contact angles of ~99° and 102° for control and antifouling PDMS surfaces, respectively. The control PDMS sliding angle (>90°) was significantly reduced to 9° after antifouling preparation. After 24 h incubation of polymer samples in a 200 mg/mL bovine serum albumin (BSA) solution, the surface adsorbed BSA was quantified using a colorimetric assay. The adsorbed protein on the fouling PDMS controls (29.1 ± 7.0 μg/cm2) was reduced by ~79% on the antifouling PDMS surface (6.2 ± 0.9 μg/cm2). Students will gain experience in materials science, biomedical engineering, chemistry, and biology concepts and better understand the influence of material properties on biological responses for biomaterial interfaces.

From the Periodic Properties of Metals to the Rietveld Refinement of the Pharmaceutical Molecule Naproxen: Three Remote Experiments about X-ray Diffraction

Recently there is an increasing need for experiments that can be conducted remotely. In this sense, this paper presents three experiments about materials science and an X-ray diffraction (XRD) technique that can be taught and performed entirely remotely. The first experiment is about the calculation of lattice parameters, atomic radii, and densities of metallic elements with a body-centered cubic (BCC) structure. The second experiment is about the calculation of lattice parameters, axial ratios, unit cell volumes, and densities of yttria-stabilized zirconia (YSZ) solid solutions. The third experiment is about applying the Rietveld refinement technique to distinguish the enantiomers of the pharmaceutical molecule naproxen and determine the hydration degree of commercial naproxen sodium pills. For the first two experiments, students worked with simulated data, whereas for the third one, they worked with experimental data collected and provided by the Instructor. Besides the materials science and XRD concepts, students were introduced to the operation of the free softwares Vesta and GSAS II and to the Crystallography Open Database, a free database for structural data of organic and inorganic compounds. The paper explains the background, goals, and results obtained by the students in each one of the experiments. Detailed information about the experimental procedures and their implementation is complemented by the Supporting Information file and Supporting Videos. Although the experiments were presented in an increasing level of difficulty, they are independent of each other, allowing the instructors to apply them according to their needs and learning objectives.

Prismatic edge dislocations in graphite

Dislocations are a central concept in materials science, which dictate the plastic deformation and damage evolution in materials. Layered materials such as graphite admit two general types of interlayer dislocations: basal and prismatic dislocations, of which prismatic dislocations have been relatively less studied. Using density functional theory (DFT) calculations, we have examined different prismatic core structures in graphite and evaluated their structure, energetics and mobility. We find close energetic interplay between bonded and “free-standing” core structures in both zigzag and armchair directions, with a reconstructed stable zigzag core identified. We explore grain boundaries and prismatic dislocation pile-up, identifying metastable structures which may be important in energy storage. The role of interlayer stacking in core structure, dislocation glide and climb is also considered in-depth. Our calculations suggest that the prismatic dislocation core is stable up to high temperatures of approximately 1500 K in bulk graphite. Above this temperature, the breaking of bonds in the dislocation core can facilitate climb, grain-boundary motion, and the annealing of damage through prismatic dislocation glide.

(Invited) Soft Microfluidic Systems for the Skin

Biological tissues are mechanically soft, with complex, time-dependent 3D curvilinear shapes; modern microfluidic technologies are rigid, with simple, static 2D layouts. Eliminating this profound mismatch in physical properties will create vast opportunities in man-made systems that can intimately integrate with the human body, for diagnostic, therapeutic or surgical function with important, unique capabilities in fitness/wellness, sports performance and clinical healthcare. Over the last decade, a convergence of new concepts in materials science, mechanical engineering, electrical engineering and advanced manufacturing has led to the emergence of diverse, novel classes of 'biocompatible' electronic and microfluidic systems with skin-like physical properties. This talk describes the key ideas and presents some of the most recent device examples, with a focus on microfluidic platforms that can capture, manipulate and perform biomarker analysis on microliter volumes of sweat, with applications in precise hydration management in sports and fitness, including commercial devices featured on celebrity sports figures with Gatorade.

Magnet Creation by Guest Insertion into a Paramagnetic Charge-Flexible Layered Metal-Organic Framework.

Changing nonmagnetic materials to spontaneous magnets is an alchemy-inspiring concept in materials science; however, it is not impossible. Here, we demonstrate chemical modification from a nonmagnet to a bulk magnet of either a ferrimagnet or antiferromagnet, depending on the adsorbed guest molecule, in an electronic-state-flexible layered metal-organic framework, [{Ru2(2,4-F2PhCO2)4}2TCNQ(EtO)2] (1; 2,4-F2PhCO2- = 2,4-difluorobenzoate; TCNQ(EtO)2 = 2,5-diethoxy-7,7,8,8-tetracyanoquinodimethane). The guest-free paramagnet 1 undergoes a thermally driven intralattice electron transfer involving a structural transition at 380 K. This charge modification can also be implemented by guest accommodations at room temperature; 1 adsorbs several organic molecules, such as benzene (PhH), p-xylene (PX), 1,2-dichloroethane (DCE), dichloromethane (DCM), and carbon disulfide (CS2), forming 1-solv with intact crystallinity. This induces an intralattice electron transfer to produce a ferrimagnetically ordered magnetic layer. According to the interlayer environment tuned by the corresponding guest molecule, the magnetic phase is consequently altered to a ferrimagnet for the guests PhH, PX, DCE, and DCM or an antiferromagnet for CS2. This is the first demonstration of the postsynthesis of bulk magnets using guest-molecule accommodations.

Prismatic Edge Dislocations in Graphite

Dislocations are a central concept in materials science, which dictate the plastic deformation and damage evolution in materials. Layered materials such as graphite admit two general types of interlayer dislocations: basal and prismatic dislocations, of which prismatic dislocations have been relatively less studied. Using density functional theory (DFT) calculations, we have examined different prismatic core structures in graphite and evaluated their structure, energetics and mobility. We find close energetic interplay between bonded and “free-standing” core structures in both zigzag and armchair directions, with a reconstructed stable zigzag core identified. We explore grain boundaries and prismatic dislocation pile-up, identifying metastable structures which may be important in energy storage. The role of interlayer stacking in core structure, dislocation glide and climb is also considered in-depth. Our calculations suggest that the prismatic dislocation core is stable up to high temperatures of approximately 1500K in bulk graphite. Above this temperature, the breaking of bonds in the dislocation core can facilitate climb, grain-boundary motion, and the annealing of damage through prismatic dislocation glide.

Failure Analysis of a Fractured Stick End Casting: An ASM Materials Camp Investigation

Students attending ASM Materials Education Foundation camps are taught about and engage in a variety of materials science and engineering concepts—including failure analysis. As part of the weeklong camp, high school students perform failure analysis on actual fractured components and present their results at the end of the camp. In this case, the students of one group were tasked with determining the failure of a stick end from a commercial pasta drying system. This paper will detail their results, obtained by performing optical and electron microscopy, as well as chemical and mechanical testing. Their analysis determined that poor manufacturing practices and a lack of maintenance led to continued failure of these parts in service.