Nucleation Energy Research Articles

Rapid hydration and weakening of anhydrite under stress: implications for natural hydration in the Earth's crust and mantle

Abstract. Mineral hydration is an important geological process that influences the rheology and geochemistry of rocks and the fluid budget of the Earth's crust and mantle. Constant-stress differential compaction (CSDC) tests, dry and “wet” tests under confining pressure, and axial-stress tests were conducted for the first time to investigate the influence of triaxial stress on hydration in anhydrite–gypsum aggregates. Characterization of the samples before and after triaxial experiments was performed with optical and scanning electron microscopy, including energy-dispersive spectroscopy and electron backscatter diffraction mapping. Stress–strain data reveal that samples that underwent constant-stress differential compaction in the presence of fluids are ∼ 14 % to ∼ 41 % weaker than samples deformed under wet conditions. The microstructural analysis shows that there is a strong temporal and spatial connection between the geometry, distribution, and evolution of fractures and hydration products. The increasing reaction surface area in combination with pre-existing gypsum in a gypsum-bearing anhydrite rock led to rapid gypsification. The crystallographic orientations of newly formed vein gypsum have a systematic preferred orientation for long distances along veins, beyond the grain boundaries of wall-rock anhydrite. Gypsum crystallographic orientations in {100} and {010} are systematically and preferentially aligned parallel to the direction of maximum shear stress (45∘ to σ1). Gypsum is also not always topotactically linked to the wall-rock anhydrite in the immediate vicinity. This study proposes that the selective inheritance of crystal orientations from favourably oriented wall-rock anhydrite grains for the minimization of free energy for nucleation under stress leads to the systematic preferred orientation of large, new gypsum grains. A sequence is suggested for hydration under stress that requires the development of fractures accompanied by localized hydration. Hydration along fractures with a range of apertures up to 120 µm occurred in under 6 h. Once formed, gypsum-filled veins represent weak surfaces and are the locations of further shear fracturing, brecciation, and eventual brittle failure. These findings imply that non-hydrostatic stress has a significant influence on hydration rates and subsequent mechanical strength of rocks. This phenomenon is applicable across a wide range of geological environments in the Earth's crust and upper mantle.

Bio‐Inspired Polyanionic Electrolytes for Highly Stable Zinc‐Ion Batteries

AbstractFor zinc‐ion batteries (ZIBs), the non‐uniform Zn plating/stripping results in a high polarization and low Coulombic efficiency (CE), hindering the large‐scale application of ZIBs. Here, inspired by biomass seaweed plants, an anionic polyelectrolyte alginate acid (SA) was used to initiate the in situ formation of the high‐performance solid electrolyte interphase (SEI) layer on the Zn anode. Attribute to the anionic groups of −COO−, the affinity of Zn2+ ions to alginate acid induces a well‐aligned accelerating channel for uniform plating. This SEI regulates the desolvation structure of Zn2+ and facilitates the formation of compact Zn (002) crystal planes. Even under high depth of discharge conditions (DOD), the SA‐coated Zn anode still maintains a stable Zn stripping/plating behavior with a low potential difference (0.114 V). According to the classical nucleation theory, the nucleation energy for SA‐coated Zn is 97 % less than that of bare Zn, resulting in a faster nucleation rate. The Zn||Cu cell assembled with the SA‐coated electrode exhibits an outstanding average CE of 99.8 % over 1,400 cycles. The design is successfully demonstrated in pouch cells, where the SA‐coated Zn exhibits capacity retention of 96.9 % compared to 59.1 % for bare Zn anode, even under the high cathode mass loading (>10 mg/cm2).

Bio-Inspired Polyanionic Electrolytes for Highly Stable Zinc-Ion Batteries.

For zinc-ion batteries (ZIBs), the non-uniform Zn plating/stripping results in a high polarization and low Coulombic efficiency (CE), hindering the large-scale application of ZIBs. Here, inspired by biomass seaweed plants, an anionic polyelectrolyte alginate acid (SA) was used to initiate the in situ formation of the high-performance solid electrolyte interphase (SEI) layer on the Zn anode. Attribute to the anionic groups of -COO- , the affinity of Zn2+ ions to alginate acid induces a well-aligned accelerating channel for uniform plating. This SEI regulates the desolvation structure of Zn2+ and facilitates the formation of compact Zn (002) crystal planes. Even under high depth of discharge conditions (DOD), the SA-coated Zn anode still maintains a stable Zn stripping/plating behavior with a low potential difference (0.114 V). According to the classical nucleation theory, the nucleation energy for SA-coated Zn is 97 % less than that of bare Zn, resulting in a faster nucleation rate. The Zn||Cu cell assembled with the SA-coated electrode exhibits an outstanding average CE of 99.8 % over 1,400 cycles. The design is successfully demonstrated in pouch cells, where the SA-coated Zn exhibits capacity retention of 96.9 % compared to 59.1 % for bare Zn anode, even under the high cathode mass loading (>10 mg/cm2 ).

Thiocyanate-Stabilized Pseudo-cubic Perovskite CH(NH2)2PbI3 from Coincident Columnar Defect Lattices.

α-FAPbI3 (FA+ = CH(NH2)2+) with a cubic perovskite structure is promising for photophysical applications. However, α-FAPbI3 is metastable at room temperature, and it transforms to the δ-phase at a certain period of time at room temperature. Herein, we report a thiocyanate-stabilized pseudo-cubic perovskite FAPbI3 with ordered columnar defects (α'-phase). This compound has a √5ap × √5ap × ap tetragonal unit cell (ap: cell parameter of primitive perovskite cell) with a band gap of 1.91 eV. It is stable at room temperature in a dry atmosphere. Furthermore, the presence of the α'-phase in a mixed sample with the δ-phase drastically reduces the δ-to-α transition temperature measured on heating, suggesting the reduction of the nucleation energy of the α-phase or thermodynamic stabilization of the α-phase through epitaxy. The defect-ordered pattern in the α'-phase forms a coincidence-site lattice at the twinned boundary of the single crystals, thus hinting at an epitaxy- or strain-based mechanism of α-phase formation and/or stabilization. In this study, we developed a new strategy to control defects in halide perovskites and provided new insight into the stabilization of α-FAPbI3 by pseudo-halide and grain boundary engineering.

Significantly enhanced high-temperature mechanical properties of Cu-Cr-Zn-Zr-Si alloy with stable second phases and grain boundaries

Improving high-temperature strength and resistance to high-temperature softening is an important method to promote the application of high-performance Cu-Cr-Zr alloy in fields such as resistance welding electrodes and high-speed railway contact wires. A Cu-1.0Cr-0.4Zn-0.1Zr-0.05Si alloy was designed and the combining effects of Zn and Si elements on the microstructure and high-temperature mechanical properties of the alloy were studied. The tensile strength of the alloy at room temperature was 556 MPa, and it was 349 MPa at 500℃ with a softening temperature of 620℃. The main strengthening phases of the alloy were submicron Cr3Si and nano-scaled Cr-rich precipitates. The Zn elements were uniformly solid-solved in the Cu matrix, and the addition of Zn and Si elements significantly retarded the phase transformation of the Cr-rich precipitates. Thermodynamics and kinetics analysis showed that Zn and Si elements promoted the dispersive precipitation of the nano-scaled FCC coherent Cr-rich precipitates by reducing the nucleation energy barrier, while the Si and Zr elements inhibited the coarsening of the Cr-rich precipitates by enriching at the phase boundaries, effectively impeding dislocation motion and grain boundary migration, which mainly contributed to good high-temperature strength and resistance to softening of the Cu-Cr-Zn-Zr-Si alloy.

High Capacity Sn Metal Anode for Aqueous Proton-Based Batteries

Aqueous proton-based batteries (APBs) as a good choice to respond battery diversity, delivering safety, cost, environmental friendliness and high-power necessary for renewable energy storage.1 However, most promising conventional aqueous battery anodes have relatively poor compatibility in acid. The limited existing anode options like Pb and MoO3 can hardly match the high-performance of advanced cathodes, leading low-voltage and unsatisfactory energy density of APBs.2-4 Therefore, the exploration of high-performance anode materials is thus of critical issue for the APB assembling.Sn metal should be one of the most suitable APB anode choices due to its relatively high hydrogen evolution reaction (HER) overpotential, large theoretical capacity (451.6 mAh g−1) and negative redox potential (−0.14 V vs. SHE). With a body-centered tetragonal crystal structure and similar facet surface energy, Sn metal deposit in polyhedral morphology isotropically. This may cause serious “dead Sn” issue when deposition capacity increases because large Sn particle has limited contact with the substrate and easily to shed from the electrode, resulting in low Coulombic efficiency and short lifespan.We will present our efforts of developing Sn anode with high capacity and long lifespan by an interfacial alloying regulation approach. Smaller grain size and more uniform Sn deposition can be achieved by higher propensity for nucleation and Sn migration energy barrier. Extra interfacial interaction suppresses shedding of Sn polyhedron particles, thus prohibiting the formation of “dead” Sn. Based on the optimized Sn metal anode, we propose several promising designs for APBs, with high performance such as high output voltages, good specific energy densities, fast kinetics, and long life. References X. Wu, J. J. Hong, W. Shin, L. Ma, T. Liu, X. Bi, Y. Yuan, Y. Qi, T. W. Surta, W. Huang, J. Neuefeind, T. Wu, P. A. Greaney, J. Lu, X. Ji. Nat. Energy 2019, 4, 123-130.W. Chen, G. Li, A. Pei, Y. Li, L. Liao, H. Wang, J. Wan, Z. Liang, G. Chen, H. Zhang, J. Wang, Y. Cui. Nat. Energy 2018, 3, 428-435.Y. Liang, Y. Jing, S. Gheytani, K. Y. Lee, P. Liu, A. Facchetti, Y. Yao. Nat. Mater. 2017, 16, 841-848.X. Wang, Y. Xie, K. Tang, C. Wang, C. Yan. Angew. Chem. Int. Ed. 2018, 57, 11569-11573.

Multifunctional Catalytic Hierarchical Interfaces of Ni12 P5 -Ni2 P Porous Nanosheets Enabled Both Sulfides Reaction Promotion and Li-Dendrite Suppression for High-Performance Li-S Full Batteries.

The development of lithium-sulfur (Li-S) batteries is very promising and yet faces the issues of hindered polysulfides conversion and Li dendrite growth. Different from using different materials strategies to overcome these two types of problems, here multifunctional catalytic hierarchical interfaces of Ni12 P5 -Ni2 P porous nanosheets formed by Ni2 P partially in situ converted from Ni12 P5 are proposed. The unique electronic structure in the interface endows Ni12 P5 -Ni2 P effective electrocatalysis effect toward both sulfides' reduction and oxidation through reducing Gibbs free energies, indicating a bidirectional conversion acceleration. Importantly, Ni12 P5 -Ni2 P porous nanosheets with hierarchical interfaces also reduced the Li nucleation energy barrier, and a dendrite-free Li deposition is realized during the overall Li deposition and stripping steps. To this end, Ni12 P5 -Ni2 P decorated carbon nanotube/S cathode showing a high capacity of over 1500 mAh g-1 , and a high rate capability of 8 C. Moreover, the coin full cell delivered a high capacity of 1345 mAh g-1 at 0.2 C and the pouch full cell delivered a high capacity of 1114 mAh g-1 at 0.2 C with high electrochemical stability during 180° bending. This work inspires the exploration of hierarchical structures of 2D materials with catalytically active interfaces to improve the electrochemistry of Li-S full battery.

Regulated Zn Plating and Stripping by a Multifunctional Polymer-Alloy Interphase Layer for Stable Zn Metal Anode.

Metallic zinc electrode with a high theoretical capacity of 820mAhg-1 is highly considered as a promising candidate for next-generation rechargeable batteries. However, the unavoidable hydrogen evolution, uncontrolled dendrite growth, and severe passivation reaction badly hinder its practical implementations. Herein, a robust polymer-alloy artificial protective layer is designed to realize dendrite-free Zn metal anode by the integration of zincophilic SnSb nanoparticles with Nafion. In comparison to the bare Zn electrode, the Nafion-SnSb coated Zn (NFSS@Zn) electrode exhibits lower nucleation energy barrier, more uniform electric field distribution and stronger anti-corrosion capability, thus availably suppressing the Zn dendrite growth and interfacial side reactions. As a consequence, the NFSS@Zn electrode exhibits a long cycle life over 1500h at 1mAcm-2 with an ultra-low voltage hysteresis (25mV). Meanwhile, when paired with a MnO2 cathode, the as-prepared full cell also demonstrates stable performance for 1000cycles at 3Ag-1 . This work provides an inspired approach to boost the performance of Zn anodes.

Nucleation of L12-Al3M (M = Sc, Er, Y, Zr) Nanophases in Aluminum Alloys: A First-Principles ThermodynamicsStudy

High-performance Sc-containing aluminum alloys are limited in their industrial application due to the high cost of Sc elements. Er, Zr, and Y elements are candidates for replacing Sc elements. Combined with the first-principles thermodynamic calculation and the classical nucleation theory, the nucleation of L12-Al3M (M = Sc, Er, Y, Zr) nanophases in dilutealuminum alloys were investigated to reveal their structural stability. The calculated results showed that the critical radius and nucleation energy of the L12-Al3M phases were as follows: Al3Er > Al3Y > Al3Sc > Al3Zr. The Al3Zr phase was the easiest to nucleate in thermodynamics, while the nucleation of the Al3Y and Al3Er phases were relatively difficult in thermodynamics. Various structures of Al3(Y, Zr) phases with the radius r < 1 nm can coexist in Al-Y-Zr alloys. At a precipitate’s radius of 1–10 nanometers, the core–shelled Al3Zr(Y) phase illustrated the highest nucleation energy, while the separated structure Al3Zr/Al3Y obtained the lowest one, and had thermodynamic advantages in the nucleation process. Moreover, the core–shelled Al3Zr(Y) phase obtained a higher nucleation energy than Al3Zr(Sc) and Al3Zr(Er). Core–doubleshelled Al3Zr/Er(Y) obtained a lower nucleation energy than that of Al3Zr(Y) due to the negative ΔGchem of Al3Er and the negative Al3Er/Al3Y interfacial energy, and was preferentially precipitated in thermodynamics stability.

Effect of calcium pimelate on crystallization kinetics of polyphenylene sulfide

AbstractThe use of nucleating agents (NAs) to accelerate semicrystalline polymers crystallization is a widely recognized technique during processing. However, the commercially available NA for poly(phenylene sulfide) (PPS) has been rather limited. In this work, it is found that calcium pimelate (CaPim), a commercial nucleating agent for isotactic polypropylene, could also accelerate the crystallization process of PPS. The influence of CaPim addition on the crystallization behaviors of PPS was investigated under non‐isothermal and isothermal condition. Upon the addition of 0.3 wt% CaPim, the crystallization peak temperature and the onset crystallization temperature increases by 5.3 and 8.4°C at 10°C/min cooling rate, and the half‐time of crystallization reduces 51% at crystallization temperature of 272°C. Polarized optical observation revealed a substantial enhancement in nucleation due to the presence of CaPim. Avrami equation analysis suggested that the nucleating agent significantly increased the crystallization rate constant without affecting the growth dimension. Moreover, Lauritzen–Hoffman theory analysis indicateed that the addition of CaPim lowers the nucleation energy barrier, contributing to its high‐nucleation efficiency. These findings demonstrate that calcium pimelate holds promise as an effective nucleating agent for PPS.

Lithiophilic composite solid electrolyte interphase layer modified Li foils: Li metal battery failure analysis

Li metal battery with higher energy density becomes increasing important to reach a carbon neutrality society. However, the usage of Li metal is usually failed due to the side-reactions, dendrite formations, and volume expansion. To tackle these difficulties, artificial solid electrolyte interphase with multiple functions is proposed. In our work, a magnesium-based inorganic-organic film is coated on Li metal with tape-casting. LixMg alloy and nano-LiF particles produced after activation process can lower the nucleation energy barriers and increase the Li ion transportation. Polymer layers with high flexibility are adopted to control the volume change caused by repeatly lithium plating/stripping. As a result, the Li symmetrical cell runs stable for 1300 h with a lower over-potential of 3 mV under limited carbonate electrolyte. Li metal batteries degradation mechanism with different N/P ratio and C rates are discussed in details. The full cell with LiFePO4 and 30 μm Li foil delivers a capacity of 132 mA h g−1 after 300 cycles, the bare Li is dead after 75 cycles due to the loss of active lithium. LiNi0.6Co0.2Mn0.2O2 coupled with modified Li foil with mass loading of 1.44 mA h cm−2 is superior than bare Li at 1 C, the latter quickly die due to the dry-out of electrolyte.

NUCLEATION AND CRYSTALS GROWTH IN THE VOLUME OF GLASS Li2O–Al2O3–SiO2 SYSTEM

By the Marotta et al method, temperature of 670 ?C at a holding time of 2 hours provides the maximum rate of nucleation the crystalline phase of ?-eucryptite-like solid solutions was found. The activation energy of nucleation and the Avrami parameter were measured by the DSC method, allowing to estimate the crystallization characteristics. The gradient crystallization method has established the temperature range of heat treatment, within which it is possible to obtain a transparent glass-ceramic. The refinement of regime the nucleation stage made it possible to reduce the time of the second stage crystallization required for the complete formation of the transparent glass-ceramic structure. Varying the holding time at a temperature of 710 ?C makes it possible to smoothly change the CTE in the range of ?(3…+41)?10–7 K?1 in the temperature range from ?120 to +500 ?C.

In-situ confined growth of defective MIL-100(Fe) in macroporous polyacrylate spherical substrate at room temperature for high-efficient toluene removal

The hazard caused by toluene has attracted worldwide attention, and it is of practical significance to study the efficient adsorption of toluene for environmental governance. In this work, a hierarchical metal–organic framework (MOF), MIL-100(Fe), was crystallized on the surface of a macroporous polyacrylate (PAA) spherical substrate at room temperature through an in-situ confinement growth strategy to form MIL-100(Fe)@PAA composite. By decreasing the nucleation energy barrier, the average size of MIL-100(Fe) crystals was reduced from 400 nm to 55 nm and defects as adsorption sites for toluene were able to install in the crystal lattices. Therefore, the composite provided excellent static and dynamic adsorption properties for toluene, much better than the pristine MIL-100(Fe). The potential mechanism for crystal defects to significantly improve the adsorption performance was subsequently explored through kinetic fitting and density functional theory (DFT) calculation. All results indicated that the innovative MIL-100(Fe)@PAA prepared using defect engineering and effective molding technology was potent in both toluene removal and regeneration, which was expected to provide a new avenue for the facile synthesis of molded MOF composites.

Surface Overpotential as a Key Metric for the Discharge-Charge Reversibility of Aqueous Zinc-Ion Batteries.

Aqueous zinc-ion batteries (AZIBs) are receiving increasing attention for power-grid energy storage systems. Nevertheless, warranting long-term reversible operation is not trivial owing to uncontrolled interfacial phenomena related to zinc dendritic growth and parasitic reactions. Herein, the addition of hexamethylphosphoramide (HMPA) to the electrolyte revealed the surface overpotential (|ηs|) to be a key metric of the reversibility. HMPA adsorbs onto active sites on the zinc metal surface, raising the surface overpotential toward lowering the nucleation energy barrier and decreasing the critical size (rcrit) of nuclei. We also correlated the observed interface-to-bulk properties by the Wagner (Wa) dimensionless number. The controlled interface enables a Zn|V6O13 full cell to retain 75.97% capacity for 2000 cycles, with a capacity loss of only 1.5% after 72 h resting. Our study not only delivers AZIBs with unparalleled cycling and storage performance but also proposes surface overpotential as a key descriptor regarding the sustainability of AZIB cycling and storage.

Hydrodynamics (Reynolds number) determine scaling, nucleation and crystal growth kinetics in membrane distillation crystallisation

Reynolds number (Re) has been previously related to several scaling mitigation and crystallisation strategies that offer distinct hypotheses for how Re may regulate the kinetics of nucleation and crystal growth in membrane crystallisation. Such ambiguity has arisen from the present inability to discretely characterise induction time in membrane systems. This study therefore introduces techniques for the detection of induction time, with measurements used to develop a modified power-law relation between nucleation rate and supersaturation to establish how Re can be used to adjust nucleation kinetics. Increasing Re enhanced mass and heat transfer processes which raised permeate flux. The interfacial supersaturation set by the increase in flux, also modified the supersaturation rate at induction for crystals formed in the bulk solution, providing the first direct evidence that it is the supersaturation level set within the boundary layer which controls primary nucleation in the bulk solution. Bulk nucleation rate can therefore be adjusted in proportion to Re. While the extent of scaling was also determined by the interfacial supersaturation set by Re, its formation was shown to be more dependent on the interfacial diffusion coefficient which regulates solute backtransport and the activation energy for nucleation. Through this work we suggest that the nucleation mechanisms underlying scale formation and bulk crystallisation are distinct. The regulation of nucleation rate in the bulk solution by Re is described analytically through classical nucleation theory, while scaling can be mitigated through operation below a critical threshold supersaturation value that determines the rate and type of scaling that prevails. These seemingly distinct strategies can be combined through modifications to T and dT with Re to suppress scaling and offer refined control over the kinetics of nucleation and crystal growth.

Anti-Icing Mechanism for a Novel Slippery Aluminum Stranded Conductor.

The icing of transmission conductor seriously threatens the safe operation of power grids. Slippery lubricant-infused porous surface (SLIPS) has shown great potential for anti-icing applications. However, aluminum stranded conductors have complex surfaces, and the current SLIPSs are almost prepared and studied on small flat plates. Herein, the construction of SLIPS on the conductor was realized through anodic oxidation and the anti-icing mechanism of the slippery conductor was studied. Compared to the untreated conductor, the SLIPS-conductor reduces the icing weight by 77% in the glaze icing test and shows very low ice-adhesion strength (7.0 kPa). The excellent anti-icing performance of the slippery conductor is attributed to the droplet impact dynamics, icing delay, and lubricant stability. The dynamic behavior of water droplets is most affected by the complex shape of the conductor surface. Specifically, the impact of the droplet on the conductor surface is asymmetric and the droplet can slide along the depression in low-temperature and high-humidity environments. The stable lubricant of SLIPS increases both the nucleation energy barriers and the heat transfer resistance, which greatly delays the freezing time of droplets. Besides, the nanoporous substrate, the compatibility of the substrate with the lubricant, and the lubricant characteristics contribute to the lubricant stability. This work provides theoretical and experimental guidance on anti-icing strategies for transmission lines.

Engineering of Defective MOF-801 Nanostructures within Macroporous Spheres for Highly Efficient and Stable Water Harvesting.

Water harvesting using the metal-organic framework (MOF)-801 is restricted by limited working capacity, powder structuring, and finite stability. To overcome these issues, wecrystallized MOF-801 on the surface of macroporous poly(N-isopropylacrylamide-glycidyl methacrylate) spheres, called P(NIPAM-GMA), through an in situ confined growth strategy, forming spherical MOF-801@P(NIPAM-GMA) composite with temperature-responsive function. By lowering the nucleation energy barrier, the average size of the MOF-801 crystals decreased by 20 times. Thus, abundant defects as adsorption sites for water couldbe installed in the crystals lattices. As a consequence, the composite provides an unprecedented high water harvesting efficiency. The composite wasproduced in the kilogram-scale and can capture 1.60kg H2 O/kg composite/day from 20% RH between 25°C and 85°C. This work provides an effective methodology for improving the adsorption capacity through controlled defects formation as adsorption sites and to improve the kinetics through the design of a composite with macroporous transport channel network. This article is protected by copyright. All rights reserved.

Controllable Etching of Ti3SiC2 to Produce Fluorine‐Enriched, Hydrophobic 2D Titanium Carbide for Ultrastable Zinc Ion Batteries

AbstractMXenes are mainly produced via selectively etching MAX phases in aqueous F‐containing solutions, commonly showing a highly hydrophilic character due to their plentiful ‐O and ‐OH terminations. However, the hydrophilic nature of MXenes may deteriorate their durability and stability as employed in humid and aqueous environments. Here, this work demonstrates a new etching approach to produce fluorine‐enriched MXene Ti3C2Fx via selective etching of Si from Ti3SiC2 in sulfur hexafluoride (SF6) gas. During the etching process, SF6 enables the selective removal of Si species with the formation of volatile SiF4 and efficiently reacts with the exposed surface of Ti3C2 slabs, affording Ti3C2Fx MXene with a fraction of ‐F termination up to 87 at.% and good hydrophobicity. Such hydrophobic Ti3C2Fx MXene is beneficial to suppress water‐induced side reactions and decrease the Zn nucleation energy barrier, delivering a long cyclic lifespan of 1200 h and superior rate performance up to 6.4 mA cm−2 in Ti3C2Fx/Zn symmetric cells. Coupled with nickel hexacyanoferrate (NiHCF) as a cathode, the zinc full cell with Ti3C2Fx/Zn anode exhibits good rate capabilities (58 mAh g−1, 3.2 A g−1) and long cycling stability up to 1000 cycles at 3.2 A g−1.

Centimeter-Transferable III-Nitride Membrane Enabled by Interfacial Adhesion Control for a Flexible Photosensitive Device.

Flexible III-nitride-based optoelectronic devices are crucial for the next-generation foldable/wearable lighting sterilization and sensor working in the ultraviolet (UV) region. However, the strong bonding effect at the epitaxial interface of III-nitride and bare sapphire substrate makes it difficult for epilayer separation and flexible applications. Although the emerging van der Waals epitaxy (vdWE) with graphene insertion layer offers a feasible route for weakening the interfacial adhesion, the intact centimeter-transferable III-nitride membrane still remains challenging. The spontaneous delamination occurs due to the too weak interfacial adhesion of pure vdW force, and on the contrary, the structural damage of graphene by high-temperature hydrogen etching during the III-nitride growth might also cause separation failure. Up to now, the efficient control of vdWE interfacial adhesion is still an on-going research hotspot. Herein, we demonstrate the interfacial adhesion control of III-nitride vdWE by utilizing graded high-temperature nitridation treatment of the graphene insertion layer, which generates defects and N doping in different levels. The corresponding epitaxial modes of pure-vdWE, quasi-vdWE, and mixed epitaxy are achieved according to the interfacial adhesion difference. It reveals that the quasi-vdWE enabled by small graphene defects and proper N doping triggers the low formation energy for AlN nucleation; meanwhile, the proper interfacial adhesion ensures the growth integrality and intact separation of III-nitride membrane in the centimeter scale. The UV resin-assisted bonding technique is proposed for the successful transfer of III-nitride onto a flexible substrate. The flexible photodetector is fabricated by using a graphene monolayer as the photocarrier transport channel, and it achieves a high device yield of 90%, retaining ∼60% of its initial performance after 250 bending cycles. This work offers the promising strategy for controlling vdWE interfacial adhesion, and the separable and transferable III-nitride membrane lays the foundation for advances of future UV foldable and wearable devices.

Protein Nucleation and Crystallization Process with Process Analytical Technologies in a Batch Crystallizer.

Protein crystallization has drawn great attention to replacing the traditional downstream processing for protein-based pharmaceuticals due to its advantages in stability, storage, and delivery. Limited understanding of the protein crystallization processes requires essential information based on real-time tracking during the crystallization process. A batch crystallizer of 100 mL fitted with a focused beam reflectance measurement (FBRM) probe and a thermocouple was designed for in situ monitoring of the protein crystallization process, with simutaneously record of off-line concentrations and crystal images. Three stages in the protein batch crystallization process were identified: long-period slow nucleation, rapid crystallization, and slow growth and breakage. The induction time was estimated by FBRM, i.e., increasing numbers of particles in the solution, which could be half of the time required for detecting the decrease of the concentration, by offline measurement. The induction time decreased with an increase in supersaturation within the same salt concentration. The interfacial energy for nucleation was analyzed based on each experimental group with equal salt concentration and different concentrations of lysozyme. The interfacial energy reduced with an increase in salt concentration in the solution. The yield of the experiments was significantly affected by the protein and salt concentrations and could achieve up to 99% yield with a 26.5 μm median crystal size upon stabilized concentration readings.