Design Of Multifunctional Materials Research Articles

Biomimicry of iridescent, patterned insect cuticles: comparison of biological and synthetic, cholesteric microcells using hyperspectral imaging.

Biological systems inspire the design of multifunctional materials and devices. However, current synthetic replicas rarely capture the range of structural complexity observed in natural materials. Prior to the definition of a biomimetic design, a dual investigation with a common set of criteria for comparing the biological material and the replica is required. Here, we deal with this issue by addressing the non-trivial case of insect cuticles tessellated with polygonal microcells with iridescent colours due to the twisted cholesteric organization of chitin fibres. By using hyperspectral imaging within a common methodology, we compare, at several length scales, the textural, structural and spectral properties of the microcells found in the two-band cuticle of the scarab beetle Chrysina gloriosa with those of the polygonal texture formed in flat films of cholesteric liquid crystal oligomers. The hyperspectral imaging technique offers a unique opportunity to reveal the common features and differences in the spectral-spatial signatures of biological and synthetic samples at a 6-nm spectral resolution over 400 nm-1000 nm and a spatial resolution of 150 nm. The biomimetic design of chiral tessellations is relevant to the field of non-specular properties such as deflection and lensing in geometric phase planar optics.

Bioinspired polypeptide as building blocks for multifunctional material design

The exceptional mechanical properties of spider silks from their extraordinary natural design make them outstanding biomaterial candidates. Herein, inspired by the outer egg sac silk from Nephila pilipes, we introduce a gradient of recombinant biomimetic polypeptides (BMPPs) through a semi-rational design. The synthesized BMPPs show good water solubility with dynamic conformations of random coil/helix. Both biomimetic nanofiber membranes and macrofiber yarns are fabricated using BMPPs as blend with polycaprolactone (PCL) through electrospinning. The resulting nanofiber membrane yields almost double tensile strength (22.7 ± 3.3 MPa) compared to that of PCL (12.5 ± 1.4 MPa), without sacrifice of toughness. The as-fabricated microfiber yarns could accommodate both improvement of tensile strength (208 ± 8.3 MPa, almost twice of PCL value) and toughness (163 ±13 MJ/m3, more than twice of PCL value), suggesting the crosslink role of BMPP in PCL network. By fusion of cell-binding domains in the BMPP, the materials also illustrate great potentials into new biomedical materials.

Two-dimensional multimetallic sulfide nanosheets with multi-active sites to enhance polysulfide redox reactions in liquid Li2S6-based lithium-polysulfide batteries

Two-dimensional Cu, Zn and Sn-based multimetallic sulfide nanosheets were prepared to construct multi-active sites for the immobilization and entrapment of polysulfides with offering better performance in liquid Li 2 S 6 -based lithium-polysulfide batteries. The lithium-sulfur battery has attracted enormous attention as being one of the most significant energy storage technologies due to its high energy density and cost-effectiveness. However, the “shuttle effect” of polysulfide intermediates represents a formidable challenge towards its wide applications. Herein, we have designed and synthesized two-dimensional Cu, Zn and Sn-based multimetallic sulfide nanosheets to construct multi-active sites for the immobilization and entrapment of polysulfides with offering better performance in liquid Li 2 S 6 -based lithium-polysulfide batteries. Both experimental measurements and theoretical computations demonstrate that the interfacial multi-active sites of multimetallic sulfides not only accelerate the multi-chained redox reactions of highly diffusible polysulfides, but also strengthen affinities toward polysulfides. By adopting multimetallic sulfide nanosheets as the sulfur host, the liquid Li 2 S 6 -based cell exhibits an impressive rate capability with 1200 mAh/g and retains 580 mAh/g at 0.5 mA/cm 2 after 1000 cycles. With high sulfur mass loading conditions, the cell with 2.0 mg/cm 2 sulfur loading delivers a cell capacity of 1068 mAh/g and maintains 480 mAh/g with 0.8 mA/cm 2 and 500 cycles. This study provides new insights into the multifunctional material design with multi-active sites for elevated lithium-polysulfide batteries.

Multifunctional composites for elastic and electromagnetic wave propagation

Composites are ideally suited to achieve desirable multifunctional effective properties since the best properties of different materials can be judiciously combined with designed microstructures. Here, we establish cross-property relations for two-phase composite media that link effective elastic and electromagnetic wave characteristics to one another, including the respective effective wave speeds and attenuation coefficients, which facilitate multifunctional material design. This is achieved by deriving accurate formulas for the effective electromagnetic and elastodynamic properties that depend on the wavelengths of the incident waves and the microstructure via the spectral density. Our formulas enable us to explore the wave characteristics of a broad class of disordered microstructures because they apply, unlike conventional formulas, to a wide range of incident wavelengths (i.e., well beyond the long-wavelength regime). This capability enables us to study the dynamic properties of exotic disordered "hyperuniform" composites that can have advantages over crystalline ones, such as nearly optimal, direction-independent properties and robustness against defects. We specifically show that disordered "stealthy" hyperuniform microstructures exhibit novel wave characteristics (e.g., low-pass filters that transmit waves "isotropically" up to a finite wavenumber). Our cross-property relations for the effective wave characteristics can be applied to design multifunctional composites via inverse techniques. Design examples include structural components that require high stiffness and electromagnetic absorption; heat sinks for central processing units and sound-absorbing housings for motors that have to efficiently emit thermal radiation and suppress mechanical vibrations; and nondestructive evaluation of the elastic moduli of materials from the effective dielectric response.

Highly Adsorptive and Magneto-Inductive Guefoams (Multifunctional Guest-Containing Foams) For Enhanced Energy-Efficient Preconcentration and Management of VOCs.

The design of multifunctional materials is a current demand for high-end technological applications that need to combine different functions unable to be accomplished by a single material. The aim of this work is to present, at first glance, a new family of recently patented multifunctional porous materials developed by locating granular phases with specific functionality (guests) within the cavities of open-pore cellular materials (hosts) and, at second glance, the use of a set of these materials for the preconcentration and management of volatile organic compounds (VOCs). These materials (herein known as Guefoams, acronym for Guest-containing foams), present host foams and guest phases that are not bonded and therefore allow fluids to pass through. The processing method is the gas pressure infiltration of a host precursor into preforms containing particulate guest phases covered by a NaCl martyr coating, which is later dissolved in water. The manuscript shows the manufacture and characterization of a specific set of Guefoams composed of aluminum foams that incorporate both steel particles and activated carbon particles as guest phases into the same material. These guest phases make the materials highly adsorbent and susceptible to rapid desorption by magnetic induction, two properties never achieved with traditional foams that transform these materials into perfect candidates for preconcentration and energy-efficient management of VOCs. The manuscript concludes with a discussion on advisible properties to consider when exploring the use of these materials in the mentioned applications.

Ultrafast self-healing and highly transparent coating with mechanically durable icephobicity

Excessive ice accretion on infrastructures can lead to severe damage and dysfunction. In the context of combating the build-up of unwanted icing and at the same time maintaining sunlight transmission, for instance on solar panels, windows and sensors, mechanically durable and transparent icephobic coatings are highly desired. Herein, we design and fabricate an icephobic coating possessing for the first time combined properties of ultrafast self-healing and outperforming transparency. Our coating can restore more than 80 % of the ultimate tensile strength within 45 min of healing at room temperature after introducing a cut. By a combination of both experiments and atomistic simulations, we establish the atomistic mechanism for ultrafast self-healing, i.e. the optimal balance between polymer chain flexibility and concentration of hydrogen bonding pairs. Equipped with such ultrafast self-healing property, the coating shows a stable ice adhesion strength of 52.2 ± 8.9 kPa after 20 icing/deicing cycles, and 48.2 ± 4.6 kPa after healing from mechanical damage, exhibiting exceptional robustness for anti-icing applications that require high mechanical endurance. Importantly, the coating on glass shows a light transmittance of 89.1 % in the visible region, which is remarkably close to bare glass (91.9 %). Moreover, the coating is recyclable due to the dissociable crosslinks, providing a sustainable aspect missing in existing state-of-the-art icephobic coatings. This coating combines the properties of icephobicity, mechanical durability (via self-healing), transparency and recyclability, and thus enlightens the design of multifunctional materials for meeting complex environmental requirements encountered in the field of anti-icing.

Smart Nanovesicle-Mediated Immunogenic Cell Death through Tumor Microenvironment Modulation for Effective Photodynamic Immunotherapy.

Combination therapy that could better balance immune activation and suppressive signals holds great potential in cancer immunotherapy. Herein, we serendipitously found that the pH-responsive nanovesicles (pRNVs) self-assembled from block copolymer polyethylene glycol-b-cationic polypeptide can not only serve as a nanocarrier but also cause immunogenic cell death (ICD) through preapoptotic exposure of calreticulin. After coencapsulation of a photosensitizer, 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a (HPPH) and an indoleamine 2,3-dioxygenase inhibitor, indoximod (IND), pRNVs/HPPH/IND at a single low dose elicited significant antitumor efficacy and abscopal effect following laser irradiation in a B16F10 melanoma tumor model. Treatment efficacy attributes to three key factors: (i) singlet oxygen generation by HPPH-mediated photodynamic therapy (PDT); (ii) increased dendritic cell (DC) recruitment and immune response provocation after ICD induced by pRNVs and PDT; and (iii) tumor microenvironment modulation by IND via enhancing P-S6K phosphorylation for CD8+ T cell development. This study exploited the nanocarrier to induce ICD for the host's immunity activation. The "all-in-one" smart nanovesicles allow the design of multifunctional materials to strengthen cancer immunotherapy efficacy.

First-principles computational study of Ni/α-Al2O3 hybrid interface reactions under extreme thermodynamic conditions

Atomic-level understanding of hybrid interface reactions for metal and oxide plays an important role in innovative design of multifunctional materials. We apply first-principles calculations to thin layers of metallic Ni and oxide α-Al2O3 (Ni/α-Al2O3) and unveil reaction mechanism under extreme thermodynamic conditions (T > 2500 K and pressure P ∼ 40 GPa). In such thermally shocked state, we track interface reaction scenario by calculations of thermodynamically feasible structures and energy convex hull: (i) chemical-bond break of α-Al2O3 enabling fast diffusion of O into Ni atomic layers, (ii) formation of NiO, (iii) formation of intermetallic compounds NixAl1-x and followed by (iv) evolution of O2 gas. The NiO is formed locally at around the interface for short time period at the beginning of the interface reactions. Intermetallic compounds NixAl1−x are thermodynamically unstable against the decomposition into Al2O3 and Ni. It is also elucidated that abrupt mechanical shock to the interface by such a high pressure adiabatically raise interface temperature extremely high, in which mixtures of NixAl1−x are stabilized by releasing O2(g). We neatly summarize the interface reactions using an Ellingham diagram.

Fabrication of flexible ceramic membranes derived from hard Si3N4 and soft MnO2 nanowires

Flexible ceramic material, as a fundamental component of a toolset for the design of multifunctional materials, is very desirable, but a simple and effective preparation strategy is still missing. Herein, a flexible Si3N4/MnO2 ceramic membrane was fabricated by facile vacuum filtration progress using hard Si3N4 particles and soft ultralong MnO2 nanowires as building blocks. The Si3N4 particles were uniformly anchored into the porous flexible membrane, depending on the mechanical entanglement from ultralong MnO2 nanowires, resulting in the excellent interface stability between them. Thanks to the flexibility of MnO2 nanowires and interface stability, the as-prepared flexible membrane achieves superior flexibility including bending, folding, and twining. The flexible ceramic membrane can broaden the application range beyond the traditional ceramic use as hard structural materials. Moreover, the design strategy developed herein is applicable to other hard ceramic with similar issues.

Self-Heating Ability of Geopolymers Enhanced by Carbon Black Admixtures at Different Voltage Loads

Sustainable development in the construction industry can be achieved by the design of multifunctional materials with good mechanical properties, durability, and reasonable environmental impacts. New functional properties, such as self-sensing, self-heating, or energy harvesting, are crucially dependent on electrical properties, which are very poor for common building materials. Therefore, various electrically conductive admixtures are used to enhance their electrical properties. Geopolymers based on waste or byproduct precursors are promising materials that can gain new functional properties by adding a reasonable amount of electrically conductive admixtures. The main aim of this paper lies in the design of multifunctional geopolymers with self-heating abilities. Designed geopolymer mortars based on blast-furnace slag activated by water glass and 6 dosages of carbon black (CB) admixture up to 2.25 wt. % were studied in terms of basic physical, mechanical, thermal, and electrical properties (DC). The self-heating ability of the designed mortars was experimentally determined at 40 and 100 V loads. The percolation threshold for self-heating was observed at 1.5 wt. % of carbon black with an increasing self-heating performance for higher CB dosages. The highest power of 26 W and the highest temperature increase of about 110 °C were observed for geopolymers with 2.25 wt. % of carbon black admixture at 100 V.

Multifunctional Nanohybrid of Palladium Nanoparticles Encapsulated by Carbon‐Dots for Exploiting Synergetic Applications

AbstractPalladium nanoparticles encapsulated in the carbon dots (Pd/C‐dots) are demonstrated to play a role of multifunctional nanohybrid in the synergetic applications of sensor and catalysis. The photochemical method is applied to synthesize Pd/C‐dots in which Pd nanoparticles (NPs) are dispersedly encapsulated by C‐dots layer. The nanohybrid can function as a fluorescent sensor and reductive catalyst, due to the inherent properties of C‐dots and Pd NPs, respectively. The Pd/C‐dots exhibit a highly selective and sensitive detection toward the nickel (Ni2+) ion with a detection limit of 7.26 × 10−9 m. Moreover, the Ni2+ is detected in MCF‐7 live cells signifying the applicability of nanohybrid as a promising sensor. On the other hand, the Pd/C‐dots show an excellent catalytic performance in the reduction of 4‐nitrophenol and eosin yellow. A plausible mechanism for sensing and catalysis behavior is proposed. The sensor system is designed on the basis of the fluorescence turn‐on when Ni2+ interacts with functional groups of the C‐dots layer. The activities of catalytic reduction are mainly governed by the Pd NPs and further enhanced when the C‐dots layer is incorporated. The Pd/C‐dots can serve as a new paradigm for opening a potential trend in the design of multifunctional materials to diverse applications.

Hybrid Janus Particles: Challenges and Opportunities for the Design of Active Functional Interfaces and Surfaces.

Janus particles are a unique class of multifunctional patchy particles combining two dissimilar chemical or physical functionalities at their opposite sides. The asymmetry characteristic for Janus particles allows them to self-assemble into sophisticated structures and materials not attainable by their homogeneous counterparts. Significant breakthroughs have recently been made in the synthesis of Janus particles and the understanding of their assembly. Nevertheless, the advancement of their applications is still a challenging field. In this Review, we highlight recent developments in the use of Janus particles as building blocks for functional materials. We provide a brief introduction into the synthetic strategies for the fabrication of JPs and their properties and assembly, outlining the existing challenges. The focus of this Review is placed on the applications of Janus particles for active interfaces and surfaces. Active functional interfaces are created owing to the stabilization efficiency of Janus particles combined with their capability for interface structuring and functionalizing. Moreover, Janus particles can be employed as building blocks to fabricate active functional surfaces with controlled chemical and topographical heterogeneity. Ultimately, we will provide implications for the rational design of multifunctional materials based on Janus particles.

Electric and optical properties of Tm3+/Yb3+co-doped PZN–9PT crystals

Tm3+/Yb3+co-doped Pb(Zn1/3Nb2/3)O3–9PbTiO3 (PZN–9PT) single crystals were grown by high-temperature flux technique. The effects of Tm3+/Yb3+ ions doping on phase structure, dielectric, ferroelectric and UC luminescence properties were investigated. The XRD, Raman spectrum and TEM results reveal that the Tm3+/Yb3+ ions can diffuse into the lattice of the PZN–9PT and increase the lattice constants. The Curie temperature Tc increases from 170 °C for pure PZN–9PT to 182.5 °C for PZN–9PT: Tm3+/Yb3+. Meanwhile, the coercive field Ec of Tm3+/Yb3+ co-doped PZN–9PT reaches to 12.1 kV/cm which is nearly four times higher than that of PZN–9PT crystal. Under a 980 nm laser excitation, crystals modified by the Tm3+/Yb3+ produce UC with three colors: blue (480 nm, 1G4 → 3H6), strong near-infrared (NIR, 804 nm, 3H4 → 3H6) and weak red (652 nm, 1G4 → 3F4). Our results can provide a new way for the design of multifunctional materials used in optical-electrical devices.

Simple and efficient rhodamine-derived VO2+ and Cu2+-responsive colorimetric and reversible fluorescent chemosensors toward the design of multifunctional materials

A simple and versatile VO2+ and Cu2+ responsive colorimetric and reversible fluorescent rhodamine scaffold towards designing multifunctional materials.

Material Design Advancement Create Multifunctional Materials for Single-Layer Bonding and Debonding

Multifunctional materials are a relatively new topic in the semiconductor industry for wafer-level packaging (WLP). With the increase in processing steps and the emergence of more advanced technologies, the use of multifunctional materials will become a more integral part in the future of temporary bonding and debonding (TB/DB) as well as other advanced packaging applications. One approach to multifunctional material design incorporates adhesive and laser release attributes in one material layer. Although this is similar to a thermal release material, it has greater thermal capabilities due to its ability to be cured and undergo laser debond. Many advantages may be obtained by combining a curable adhesive and laser release layer into one material. One of the greatest advantages is the reduction in overall processing time and steps required to bond wafer pairs as well as the reduction of chemical waste, due to the use of one material compared to two or more materials which significantly reduces the cost of ownership. Curable adhesive single layer systems offer access to higher temperatures with less material flow from the curable layer, strong adhesion for high stress applications where wafers can delaminate or spontaneously debond when using multilayer mechanically debonding systems such as Fan-Out Wafer Level Packaging (FOWLP), and offer lower wafer stress and warpage due to fewer material interfaces within the bonded wafer pairs causing less potential mismatch of materials coefficient of thermal expansion(CTE). Some challenges with this concept stem from the concern of the cleanability of a curable layer and potential laser damage to the device. In order to wet clean a curable layer, which is usually very solvent resistant due to the crosslinked nature, requires harsh solvent based solutions (that may contain either strong acid or base, require long cleaning time, and high temperature). This study will address all of the aforementioned challenges and includes the developmental advancements in material designs that resulted in the creation of new multifunctional materials. These multifunctional materials have been designed to be thermally curable, prevent material reflow of the bonding layer at higher temperatures, while still remaining wet cleanable without the use of harsh chemicals and long times. As with any material that utilize laser release methods there are concerns about device damage from laser energy penetrating to the device but multifunctional materials address this in two ways: they offer high absorbance of the laser energy at all commercially available laser tool wavelengths and they can be utilized as a thicker film as they act as the bonding layer as well. By overcoming their challenges, they will minimize the cost of ownership while driving advancement in future materials and processing.

Rational design of diketopyrrolopyrrole-based multifunctional materials for organic light-emitting diodes and organic solar cells

A series of donor–acceptor diketopyrrolopyrrole derivatives has been investigated to reveal their optical, electronic, and charge transport properties for applications in organic light-emitting diodes (OLEDs) and organic solar cells (OSCs). The calculated results show that their optical, electronic, and charge transport properties are affected by the different end groups. The introduction of the 2,5-diphenylthiophene, benzo[c]isothiazole, benzo[c]thiophene, benzo[c]thiophene, 2,4-dihydrobenzo[d]thiazole, and thieno[3,4-b][1,4] dioxine end groups can broaden absorption spectrum and improve charge transport property of the designed compounds. Our results suggest that the designed compounds can serve as donor materials for OSCs and luminescent materials for OLEDs. In addition, the mobility of the designed compounds is also investigated. They are expected to be promising candidates for hole and electron transport materials. On the basis of investigated results, we proposed a rational way for the design of multifunctional materials for OLED and OSC applications.

Exceptionally Ductile and Tough Biomimetic Artificial Nacre with Gas Barrier Function.

Synthetic mimics of natural high-performance structural materials have shown great and partly unforeseen opportunities for the design of multifunctional materials. For nacre-mimetic nanocomposites, it has remained extraordinarily challenging to make ductile materials with high stretchability at high fractions of reinforcements, which is however of crucial importance for flexible barrier materials. Here, highly ductile and tough nacre-mimetic nanocomposites are presented, by implementing weak, but many hydrogen bonds in a ternary nacre-mimetic system consisting of two polymers (poly(vinyl amine) and poly(vinyl alcohol)) and natural nanoclay (montmorillonite) to provide efficient energy dissipation and slippage at high nanoclay content (50 wt%). Tailored interactions enable exceptional combinations of ductility (close to 50% strain) and toughness (up to 27.5 MJ m-3 ). Extensive stress whitening, a clear sign of high internal dynamics at high internal cohesion, can be observed during mechanical deformation, and the materials can be folded like paper into origami planes without fracture. Overall, the new levels of ductility and toughness are unprecedented in highly reinforced bioinspired nanocomposites and are of critical importance to future applications, e.g., as barrier materials needed for encapsulation and as a printing substrate for flexible organic electronics.

Design of Magnetic Coordination Polymers Built from Polyoxalamide Ligands: A Thirty Year Story

The aim of this review is to pay tribute to the legacy of O. Kahn. Kahn's credo was to synthesize magnetic compounds with predictable structure and magnetic properties. This is illustrated herein with results obtained by Kahn's group during his Orsay period thirty years ago, but also on the basis of our recent results on the synthesis of coordination polymers with oxamate ligands. The first part of this review is devoted to a short description of the necessary knowledge in physics and theoretical chemistry that Kahn and his group have used to select oxamate ligands, the complex‐as‐ligand strategy and the synthesis of heterobimetallic systems. Then, we describe the strategies we have later used to obtain the desired target compounds. The use of complexes as building‐blocks, associated to a control of the metal ions chirality and stoichiometry, allowed us to obtain coordination polymers with predictable dimensionality. For the synthesis of single‐chain magnets (SCMs) we show that the ligand chemical flexibility makes the isolation of the chains in the solid and the occurence of slow magnetic relaxation possible. For 1D and 2D molecule‐based magnets (MBMs), the magnetic ordering strongly depends on the interchain or interplane interactions, which are difficult to control. Again the flexibility of the oxamate ligands allowed their strengthening in the solid sate, yielding MBMs with critical temperatures up to 30 K. We will also present our results on 3D coordination polymers, particularly on the porous magnets displaying large octagonal channels. This family of porous MBMs possess outstanding chemical properties, such as post‐synthetic transformation in the solid state. Finally, we will also show that oxamate ligands allows the design of multifunctional materials, as in the case of the first chiral SCM. Overall, the results presented in this review show the impressive potential the oxamate ligands have for the design of coordination polymers.

Design and synthesis of organo-silica shell based dual-functional microencapsulated phase change material for thermal regulating systems

A novel form of dual-functional microcapsules with the core composition of phase change material with thermal energy storage capacity was formulated, which possessed photoluminescence features because of including rare earth nanoparticles in the core. Additionally, the core of the microcapsule is encapsulated by an organo-silica shell. The microcapsules were synthesized via interfacial polycondensation in a reverse emulsion templating system. The scanning electron microscope (SEM) and transmission electron microscopy (TEM) images of the formulated microcapsules presented a distinctive core–shell structure. The chemical compositions and crystalline structures of the microcapsules were confirmed by Fourier transform infrared spectroscopy and energy-dispersive X-ray spectroscopy, respectively. The fluorescence properties of the microcapsules were observed on an upright fluorescence microscope while the thermal properties of the microcapsules were evaluated by thermogravimetric analysis and differential scanning calorimetry. The results demonstrated that the developed strategy can certainly guide the design of multifunctional materials with numerous applications in the field of thermal energy storage.

Pore Breathing of Metal-Organic Frameworks by Environmental Transmission Electron Microscopy.

Metal-organic frameworks (MOFs) have emerged as a versatile platform for the rational design of multifunctional materials, combining large specific surface areas with flexible, periodic frameworks that can undergo reversible structural transitions, or "breathing", upon temperature and pressure changes, and through gas adsorption/desorption processes. Although MOF breathing can be inferred from the analysis of adsorption isotherms, direct observation of the structural transitions has been lacking, and the underlying processes of framework reorganization in individual MOF nanocrystals is largely unknown. In this study, we describe the characterization and elucidation of these processes through the combination of in situ environmental transmission electron microscopy (ETEM) and computer simulations. This combined approach enables the direct monitoring of the breathing behavior of individual MIL-53(Cr) nanocrystals upon reversible water adsorption and temperature changes. The ability to characterize structural changes in single nanocrystals and extract lattice level information through in silico correlation provides fundamental insights into the relationship between pore size/shape and host-guest interactions.