Morphological Evolution Research Articles

Widespread convergence towards functional optimization in the lower jaws of crocodile-line archosaurs.

Extant crocodilian jaws are subject to functional demands induced by feeding and hydrodynamics. However, the morphological and ecological diversity of extinct crocodile-line archosaurs is far greater than that of living crocodilians, featuring repeated convergence towards disparate ecologies including armoured herbivores, terrestrial macropredators and fully marine forms. Crocodile-line archosaurs, therefore, present a fascinating case study for morphological and functional divergence and convergence within a clade across a wide range of ecological scenarios. Here, we build performance landscapes of two-dimensional theoretical jaw shapes to investigate the influence of strength, speed and hydrodynamics in the morphological evolution of crocodile-line archosaur jaws, and test whether ecologically convergent lineages evolved similarly optimal jaw function. Most of the 243 sampled jaw morphologies occupy optimized regions of theoretical morphospace for either rotational efficiency, resistance to Von Mises stress, hydrodynamic efficiency or a trade-off between multiple functions, though some seemingly viable shapes remain unrealized. Jaw speed is optimized only in a narrow region of morphospace whereas many shapes possess optimal jaw strength, which may act as a minimum boundary rather than a strong driver for most taxa. This study highlights the usefulness of theoretical morphology in assessing functional optimality, and for investigating form-function relationships in diverse clades.

Glucose-assisted solvothermal synthesis of hierarchical micro-nano yolk–shell V2O3 microspheres as an anode material for lithium-ion batteries

To accelerate the development of lithium-ion batteries (LIBs), researchers should urgently exploit next-generation electrodes with high specific capacity, long cycle stability, and excellent rate performance, such as TMOs, silicon-based materials, and alloys. Among all the modification measures, hierarchical micro-nano structure and yolk–shell structure are considered suitable and effective ways to improve the electrochemical performance of those novel materials. Herein, a facile glucose-assisted solvothermal method combined with heat treatment was implemented to synthesize hierarchical micro-nano yolk–shell V2O3. The special-structured material exhibited higher specific capacity, better structure stability, and faster electrochemical kinetics compared with nanosheet-structured and micro-nano-cluster-structured V2O3. When used as an anode for LIB, mnYS-V2O3 delivered high specific capacity of 650.1 ​mA ​h ​g−1 after over 500 cycles at a current density of 100 ​mA ​g−1, with a retention of 93.4 ​%. Moreover, the morphology evolution mechanism of micro-nano structure and yolk–shell structure was investigated in this work, which is beneficial to the design of other mnYS-structured TMOs.

Spatiotemporal Characterization of the Three-Dimensional Morphology of Urban Buildings Based on Moran’s I

The three-dimensional morphological analysis of urban buildings constitutes a pivotal component of urban planning and sustainable development. Nevertheless, the majority of current research is two-dimensional in nature, which constrains the comprehensive understanding of urban spatial–temporal evolution. The existing body of three-dimensional studies frequently fails to consider the temporal dimension of architectural change and lacks a detailed examination of micro areas such as communities and streets. In order to accurately identify the patterns of spatial–temporal evolution in urban architectural morphology, this study focuses on the Yau Tsim Mong District in Hong Kong, utilizing three-dimensional data. By innovatively integrating temporal factors, constructing a spatial–temporal weight matrix, and applying the spatial–temporal Moran’s I, this study conducts an in-depth quantitative analysis of Coverage, Staggeredness, and Duty Cycle at the community scale, neighborhood scale, and urban scale. From 2014 to 2023, the global spatial–temporal Moran’s I of key urban morphology indicators in Yau Tsim Mong District has exhibited a marked increase, underscoring the close interrelationship and significant optimization between urban morphology and overall development. The findings illustrate that urban architecture is undergoing a process of agglomeration and high homogeneity, with strategic shifts emphasizing efficient spatial utilization and refined design. The analysis at the neighborhood scale is of particular importance, as its independent and complete spatial structure effectively captures local dynamics, revealing high-value agglomeration and low-value dispersion characteristics. This suggests that buildings in the Yau Tsim Mong District are being constructed in a more compact manner at the neighborhood level, which reflects the precision and efficiency of urban planning and the rationality of spatial planning. These significant findings provide valuable references for the development planning and governance of sustainable cities. They enhance urban governance capabilities and promote the optimization of urban development strategies, ensuring steady progress on the path of efficiency, harmony, and sustainability.

Damage evolution and fracture characteristics of coal rock impacted by self‐excited pulse water jet under different stress loading conditions

AbstractIn this paper, based on smoothed‐particle hydrodynamics‐finite element method, numerical models of plunger squeezing water at a sinusoidal velocity were established to simulate self‐excited pulse water jet (SEPWJ). RHT constitutive model was adopted to describe the damage and failure of coal rock impacted by water jet. The morphological evolutions of broken pits and timeliness of rock‐breaking efficiency of SEPWJ and continuous water jet (CWJ) under the conditions with and without stress loadings were obtained and compared. The evolution laws of damage and stress inner coal rock induced by jet impact, and the failure mechanism were revealed. And the influences of different stress loading magnitudes on the fracture characteristics of coal rock were investigated. The results show that the morphologies of broken pits formed by self‐excited pulse jet undergo changes in a semi‐circular, U‐shaped, V‐shaped, and bullet shaped in sequence under the stress‐free loading condition. When applying one‐dimensional (1D) and 2D stress loadings, the shallow but wide broken pits with laminar main cracks along the stress loading direction and the inverted trapezoidal bowl broken pits are formed, respectively. With the increase of 1D stress, the depth and width of broken pits slightly decrease as a quadratic parabolic function and linearly increase, respectively. And the broken pit width and area both show an exponential slow decreasing trends with the increasing 2D stress. SEPWJ can induce higher stresses to cause the earlier occurrence of initial damage and the shorter duration of damage accumulation to coal rock than CWJ, which leads to a better rock‐breaking effect. The surface and deeper coal rock elements are broken mainly due to compressive shear stresses. The 2D stress loading delays the initial damage occurrence and prolongs the damage accumulation duration due to inhibitory effect of stress loading on jet impact.

Evolution of Morphology, Particle Size and Oxidation Resistance of Recycled Ti-6Al-4V Powders Prepared by Planetary Ball Milling

AbstractPlanetary ball milling is a high-energy ball milling technique that is widely used for the synthesis of alloy and composite powders with micrometer or nanometer particle sizes. The effect of process control agent (PCA) content (wt%) and milling time on the morphology, particle size and distribution, crystallite structure, apparent density and oxidation resistance of recycled T-6Al-4V alloy powders from lathe chips is investigated in this study. To investigate the effect of the PCA on the properties of the Ti-6Al-4V alloy particles, methanol is used as the PCA in various amounts of 0.5, 1 and 2 wt%. The milling is carried out using 20:1 of ball-to-powder ratio (BPR) and 400 rpm of milling speed. A morphological change from scrap form to flake-like shape, from flake-like morphology to irregular and semispherical shape and finally from semispherical form to spherical morphology is observed with increase in milling time for all PCA ratios. The results showed that the average particle sizes (D50) are 20, 18.1 and 21.8 μm after milling of 360 min with 0.5 wt%, 1 wt% and 2 wt% PCA, respectively. Results show that the most suitable recycled Ti-6Al-4V powders for powder-based manufacturing techniques are produced between 180 and 360 min of milling with 2 wt% PCA.

Heterogeneous Solid Electrolyte Interphase Interactions Dictate Interface Instability in Sodium Metal Electrodes.

Sodium (Na) metal batteries have attracted recent attention due to their low cost and high abundance of Na. However, the advancement of Na metal batteries is impeded due to key challenges such as dendrite growth, solid electrolyte interphase (SEI) fracture, and low Coulombic efficiency. This study examines the coupled electro-chemo-mechanical interactions governing the electrodeposition stability and morphological evolution at the Na/electrolyte interface. The SEI heterogeneities influence transport and reaction kinetics leading to the formation of current and stress hotspots during Na plating. Further, it is demonstrated that the heterogeneity-induced Na metal evolution and its influence on the stress distribution critically affect the mechanical overpotential, contributing to a faster SEI failure. The analysis reveals three distinct failure mechanisms-mechanical, transport, and kinetic-that govern the onset of instabilities at the interface. Finally, a comprehensive comparative study of SEI failure in Na and lithium (Li) metal anodes illustrates that the electrochemical and mechanical characteristics of the SEI are crucial in tailoring the anode morphology and interface stability. This work delineates mechanistic stability regimes cognizant of the SEI attributes and underlying failure modes and offers important guidelines for the design of artificial SEI layers for stable Na metal electrodes.

Hydrophobic, zincophilic and conductive SEI protective layer stabilizes metallic Zn anode under high current densities

The uncontrollable growth of Zn dendrites and adverse side reactions significantly hinder the application of metallic Zn anodes in aqueous batteries. Herein, nitrogen-doped carbon skeleton/ZnO nanocrystalline are grown in-situ within carbon hollow dodecahedrons (denoted as CZCHD) through the controlled pyrolysis of zeolitic imidazole framework-8 dodecahedrons coated with polydopamine. The solid electrolyte interface layer constructed by CZCHD suppresses hydrogen evolution and corrosion reactions, reduces nucleation barrier, improves Zn deposition kinetics, accelerates desolvation and transport of Zn2+ ions, and regulates Zn deposition behavior. When tested in symmetric cells, CZCHD@Zn anodes afford exceptional plating/stripping stability at 5 mA cm−2/1 mAh cm−2 (2681 h), 10 mA cm−2/10 mAh cm−2 (780 h), and 20 mA cm−2/20 mAh cm−2 (240 h). In asymmetric cells, CZCHD@Cu exhibits average Coulombic efficiency of 99.5 % over 500 cycles. Morphological and structural evolution analyses demonstrate the preferential horizontal flaky Zn deposition beneath the CZCHD protective layer, with no Zn dendrites observed on the surface. Furthermore, when coupled with MnVO cathodes, the assembled full cells display stable cycling performance at 2 and 5 A/g. The stable, reversible, efficient, dendrite-free Zn deposition is attributed to the synergistic effects of high hydrophobicity, strong zincophilicity and high electrical conductivity of CZCHD, which is confirmed by contact angle measurements, theoretical calculations based on density functional theory, and electrochemical impedance spectroscopy.

Nanofiber array growth mechanism based on dealloying of Ti-Cu/Cu multilayer precursor film

Metal oxide nanofiber array materials are a type of material with outstanding performance and application potential. Recently, an efficient dealloying method using Ti–Cu/Cu multilayer film as a precursor was proposed to prepare titanium oxide nanofiber array structure. However, the growth mechanism and formation process of such an oxide nanofiber array grown on multilayer-film is not clear. In this work, we use Ti-Cu/Cu multilayer film as the precursor, NaOH solution as the dealloying corrosion solution, and free dealloying at room temperature. On the basis of successfully obtaining TiO2 nanofiber array films, the morphology formation and evolution process of the nanoarray were carefully monitored, and the atomic percentage changes of Ti, Cu and O elements in the dealloying precursor films were tested, as well as the formation and crystalline phase evolution trends of TiO2. Based on the experimental data, we tried to draw a schematic diagram of the formation process of this TiO2 nanofiber array, and proposed that the growth mechanism of the TiO2 nanofiber array is the precipitation growth process both with Ostwald Ripening and Oriented Attachment mechanisms. Then, the photocurrent response characteristics of the obtained nanofiber array structure samples were analyzed, and it was found that the nanofiber array structure had a certain effect on the photocurrent response performance. The completion of the present work is expected to provide a theoretical reference for the preparation and application of other metal oxide nanofiber array by dealloying method.

The Influence of a Commercial Few-Layer Graphene on Electrical Conductivity, Mechanical Reinforcement and Photodegradation Resistance of Polyolefin Blends

This work demonstrates the potentials of a commercially available few-layer graphene (FLG) in enhancing the electro-dissipative properties, mechanical strength, and UV protection of polyolefin blend composites; interesting features of electronic packaging materials. Polyethylene (PE)/ polypropylene (PP)/ FLG blend composites were prepared following two steps. Firstly, different concentrations of FLG were mixed with either the PE or PP phases. Subsequently, in the second step, this pre-mixture was melt-blended with the other phase of the blend. FLG-filled composites were characterized in terms of electrical conductivity, morphological evolution upon shear-induced deformation, mechanical properties, and UV stability of polyolefin blend composites. Premixing of FLG with the PP phase has been observed to be a better mixing strategy to attain higher electrical conductivity in PE/PP/FLG blend composite. This observation is attributed to the influential effect of FLG migration from a thermodynamically less favourable PP phase to a favourable PE phase via the PE/PP interface. Interestingly, the addition of 4 wt.% (~2 vol.%) and 5 wt.% (~2.5 vol.%) of FLG increased an electrical conductivity of ~10 orders of magnitude in PE/PP—60/40 (1.87 × 10−5 S/cm) and PE/PP—20/80 (1.25 × 10−5 S/cm) blends, respectively. Furthermore, shear-induced deformation did not alter the electrical conductivity of the FLG-filled composite, indicating that the conductive FLG network within the composite is resilient to such deformation. In addition, 1 wt.% FLG was observed to be sufficient to retain the original mechanical properties in UV-exposed polyolefin composites. FLG exhibited pronounced UV stabilizing effects, particularly in PE-rich blends, mitigating surface cracking and preserving ductility.

Numerical study of perturbed shock driven instability in a dilute gas-particle mixture

The effects of particles on the Richtmyer–Meshkov (RM) instability of a flat interface driven by perturbed and reflected shock waves are numerically investigated. By utilizing three different sizes of particles (d=5μm, 20μm and 50μm) and two types of heavy gases (SF6 and CO2), the effect of the presence of particles with different sizes on the RM instability and the dynamic process of particle diffusion have been explored, respectively. The evolution of interface morphology under smaller particle (d=5μm and 20μm) conditions bears a striking resemblance to that of the condition without particles while the large particles (d=50μm) contribute to the formation of many “wrinkles” on the interface due to the large particle size and particle inertia. The addition of particles with smaller size (d=5μm and 20μm) can either slightly inhibit or promote the growth of the mixing width at the late stage of the interface evolution, depending on the extent of interface evolution. Both the particle size and the type of heavy fluid are able to influence the particle motion.

Morphological innovation did not drive diversification in Mesozoic-Cenozoic brachiopods.

Over long spans of geological time, various groups of organisms may wax and wane, experiencing times of apparent success and contraction. These rises and falls are often said to reflect either opportunities created by climate change or the relative success of innovative characteristics. Phylum Brachiopoda was one of the most successful marine clades before the Permian/Triassic mass extinction (PTME), but after this event, they became marginal components of marine communities through to the present day. How brachiopod morphological innovations reacted to swiftly declining diversity has long remained poorly understood. Here we analyse morphological evolution over the 300 Myr (Permian-Quaternary) history of the four major Mesozoic-Cenozoic brachiopod orders (Terebratulida, Rhynchonellida, Spiriferinida, Athyridida). Unexpectedly, their disparities reached or exceeded pre-PTME levels, but were decoupled from generic richness, which was generally low. Distribution of taxa in morphospace and shifts in centroid indicate that all four orders exploited new morphospaces when adapting to post-Permian environments. A comparison of morphospace occupation and diversity evolution suggests that the high extinction rate of brachiopods and the limited diversification of new forms may have accounted for the depauperate nature of modern-day brachiopods.

Morphology evolution of lipid nanoparticle discovered by small angle neutron scattering

The structure of mRNA lipid nanoparticles (LNPs) is still under debate, with different studies presenting varying morphological characteristics, significantly hindering their biomedical potential. A typical formulation process of mRNA LNPs involves three steps: initial rapid mixing of lipids in an ethanol phase and mRNA in an acidic aqueous phase, followed by the swift removal of ethanol, and finally adjusting the solution to a neutral environment. In this study, we utilize Small Angle Neutron Scattering (SANS) with contrast matching to reveal the kinetic pathway-dependent of mRNA LNPs morphology. We find that the formulation process of the Moderna COVID-19 vaccine is controlled by a competition between aggregation and microphase separation, dictating the diverse morphologies observed in mRNA LNPs. The first step leads to the formation of polydisperse spherical droplets with an average diameter of 42±6.0 nm in an acidic ethanol aqueous solution. Ethanol removal initiates both aggregation and internal microphase separation, resulting in a polydisperse core-shell structure with an average diameter of 48±3.7 nm. Heptadecan-9-yl 8-((2-hydroxyethyl) (6-oxo-6-(undecyloxy) hexyl) amino) octanoate (SM-102) binds to mRNA via electrostatic interaction to form a reverse-wormlike micelle structure inside. The 1,2-Distearoyl-sn‑glycero-3-phosphocholine (DSPC) and PEG-lipid are just in the shell and cholesterol acting as a filler throughout the core-shell structure. Upon transitioning to a neutral environment, SM-102 loses its charge and neither the periphery nor the reverse-wormlike micelle can maintain their stabilities, leading to further aggregation and microphase separation. The average diameter of core-shell structure turns to be 66±5.2 nm. In the actual formulation process of the Moderna COVID-19 vaccine, steps 2 and 3 occur simultaneously, and the competition between aggregation and microphase separation determines the final morphology. These findings offer crucial insights into optimizing the morphology of mRNA LNPs, thereby facilitating advancements in vaccine development and mRNA vaccine delivery technologies.

Nanoscale pattern formation on surfaces by cluster ion beam irradiation

Ion beam sputtering is a solid-surface nanostructuring procedure applicable to any type of material. In this study, we are interested in the bombardment of a metallic surface, specifically, of a Co(110) surface bombarded with Ar clusters at oblique incidence. The bombardment with clusters accentuates the effect of surface ripple formation. Sputter erosion and surface atomic redistribution are the processes that determine the morphological evolution of the surface from the collisional point of view. The importance of these processes was analyzed for different angles of incidence in the bombardment with very small clusters and atoms while always maintaining the same fluence. The sputter yield increases with the number of atoms in the cluster for angles greater than 50°; while for the rest, it barely experiences any increase. Unlike sputtering, displacements increase as the cluster size increases above the critical angle. Moreover, horizontal displacement only shows some sign of saturation for angles close to the normal. An analysis of redistributed volumes and previous data suggest that sputtering drives the ripple effect for grazing angles and ones close to these. It is also responsible for the enhancement effect in the cluster bombardment. For the rest of the angles, the weight of the redistribution is decisive. There is a proportional relationship between the emptied volume and the horizontal displacement.

Exploring the Macroevolutionary Signature of Asymmetric Inheritance at Speciation.

Popular comparative phylogenetic models such as Brownian Motion, Ornstein-Ulhenbeck, and their extensions, assume that, at speciation, a trait value is inherited identically by two descendant species. This assumption contrasts with models of speciation at a micro-evolutionary scale where descendants' phenotypic distributions are sub-samples of the ancestral distribution. Different speciation mechanisms can lead to a displacement of the ancestral phenotypic mean among descendants and an asymmetric inheritance of the ancestral phenotypic variance. In contrast, even macro-evolutionary models that account for intraspecific variance assume symmetrically conserved inheritance of ancestral phenotypic distribution at speciation. Here we develop an Asymmetric Brownian Motion model (ABM) that relaxes the assumption of symmetric and conserved inheritance of the ancestral distribution at the time of speciation. The ABM jointly models the evolution of both intra- and inter-specific phenotypic variation. It also infers the mode of phenotypic inheritance at speciation, which can range from a symmetric and conserved inheritance, where descendants inherit the ancestral distribution, to an asymmetric and displaced inheritance, where descendants inherit divergent phenotypic means and variances. To demonstrate this model, we analyze the evolution of beak morphology in Darwin finches, finding evidence of displacement at speciation. The ABM model helps to bridge micro- and macro-evolutionary models of trait evolution by providing a more robust framework for testing the effects of ecological speciation, character displacement, and niche partitioning on trait evolution at the macro-evolutionary scale.

Patterns of morphological evolution in the raptorial appendages of praying mantises.

Mantodea (praying mantises) is a group of exclusively predatory insects, which, together with nonraptorial blattodeans (cockroaches and termites) and groups exclusively found in the fossil record, form the group Dictyoptera. A central characteristic of Mantodea is the specialization of their first pair of legs as raptorial grasping appendages, but the evolution from walking to raptorial legs is not yet fully understood. Here, we trace the evolution of the raptorial appendages in Dictyoptera through time using a morphometric (morphospaces) approach. We also describe two new mantodean nymphs preserved in amber from the Cretaceous and Eocene, which expand the scarce mantodean fossil record. Blattodean and mantodean appendages appear distinct in morphospace, but several appendages of fossil non-mantodeans can be considered raptorial, providing a potential transitional link between walking and raptorial morphotypes. Therefore, we discuss potential mantodean affinities for other predatory fossil dictyopterans. We examine changes across extant mantodeans, characterized by a straightening of the tibia especially associated with the rise of the diversification of the Mantidea and discuss whether a thickening of the femur could reflect an early adaptation to cursorial hunting.

Microwave-Assisted Morphological Evolution and Thermal Behavior of Expanded Graphite Interlayered Compounds

Microwave-Assisted Morphological Evolution and Thermal Behavior of Expanded Graphite Interlayered Compounds

Effect of manganese on grain morphology and microstructure of Ti-6Al-4V alloy by laser wire deposition

The addition of growth restricting elements in additive manufacturing of Ti and Ti-based alloys can result in the formation of equiaxed structures. However, an excessive incorporation of these elements frequently impairs the mechanical properties. Obtaining the minimum necessary amount of addition is crucial to achieve the transition from columnar to equiaxed microstructure. This ensures that the desired equiaxed structure is obtained while minimizing any potential negative effects on the material's properties. Here manganese was taken as the potential grain refiner in Ti alloy. Then, evolutions of grain morphologies and microstructures as well as the mechanical properties various of Ti-6Al-4V alloy in laser wire deposition additive manufacturing with the growth restriction factors of 26, 32, 39 were explored respectively. And the average hardness of the deposits were 495 HV, 512 HV, and 530 HV, respectively, showing an increase of approximately 15%, 19% and 23%. When the growth restricting factor value reached 39, the columnar prior β grains underwent a complete transformation into equiaxed grains. Mn elements promoted the decomposition of β→α+Mn2Ti during the multi-pass deposition and the microhardness of the deposits were significantly increased. Additionally, Mn elements were expelled outwards during the β→α transition. Nevertheless, the diffusion rate of Mn elements was low and thereby there was a low growth rate of α phases, thus refining α phases.

An Experimental Study of the Morphological Evolution of Rills on Slopes under Rainfall Action

Accurately monitoring the morphology and spatiotemporal evolution characteristics of the entire process of slope erosion rill development is essential to circumvent the limitations inherent in traditional methods that rely on average flow velocity for hydrodynamic parameter calculations. This study employs an environmental chamber and a self-developed slope erosion test device to perform erosion tests on slopes with varying gradients and rainfall intensities. By integrating the structure-from-motion (SfM) method, fixed grid coordinate method, and continuous camera combined with the dye tracer technique, the morphological indexes and hydrodynamic parameters of the entire rill development process are precisely computed. The main conclusions are as follows: The entire process of slope rill development can be divided into three distinct stages. The initial stage is characterized by the appearance of tiny rills with mild erosion. The middle stage involves severe transverse spreading erosion and longitudinal undercutting, resulting in diverse rill morphologies. The final stage is marked by the stabilization of morphological characteristics. The peak slope soil loss is observed during the middle stage of rill development. The most effective parameters for characterizing slope soil loss from the beginning to the end are the Reynolds number and flow shear stress, the Froude number and flow shear stress, and the Froude number during different periods. Throughout the development of rills, the flow velocity initially decreases and then gradually increases until it stabilizes. The morphological indexes, including rill density, dissected degree, inclination, and complexity, generally show an increasing trend. However, in the middle stage, the rate of increase slows down, followed by a sharp rise at certain points. The optimal hydraulic parameters for evaluating rill density across different slope gradients, which were found to be the Darcy–Weisbach drag coefficient and real-time flow velocity, for assessing rill dissected degree, complexity, and inclination, were the Reynolds number and flow power. Under varying rainfall intensities, the most effective hydraulic and kinetic parameters for evaluating rill density, dissected degree, and inclination were flow shear stress and Reynolds number; for assessing rill complexity, the Reynolds number and flow power were used. The findings of this research enhance the accuracy of hydrodynamic parameter calculations in rill erosion tests, enable precise prediction of rill development trends on slopes, and offer innovative approaches for real-time dynamic monitoring of rill morphology and characteristics. These advancements are of significant importance for soil and water conservation and sustainability.

Formation and survival of clay-mediated protocell membranes composed of single-chain amphiphiles in aqueous solutions

Protocell compartments composed of simple amphiphilic molecules could have survived on the clay mineral surfaces which can serve well as plausible sites for prebiotic chemistry on the early Earth. Herein we chose four common single-chain amphiphiles (SCAs), including the anionic surfactant sodium dodecyl sulfate (SDS) and sodium dodecylbenzenesulfonate (SDBS), the cationic surfactant dodecyltrimethylammonium bromide (DTAB) and the zwitterionic lauryl sulfobetaine (LSB)), as model constituents of early membranes to establish a tentative model for protocell compartment. Positively charged Mg2Al-/Mg2Fe-layered double hydroxides (LDHs) and FeS2 are viewed as models of clay minerals. We demonstrate by comprehensively experimental study that unconventional vesicles can be easily promoted in a SCA aqueous micellar solution in the presence of model particles. Morphology evolutions are traced by collecting samples from mixtures of LDHs and SCA aqueous solutions and then recording at different incubation times via negative-staining or cryo-transmission electron microscopy (NS-TEM or cryo-TEM) and dynamic light scattering (DLS). Additionally, the stability of SCA bilayer membranes under possible prebiotic environment are tentatively studied. This work not only offers a robust yet versatile approach for the fabrication of novel vesicles but also provides new insights into the origin of cellular life.

Single iron particle combustion - A morphology study of partially oxidized iron particles

In recent years, metal fuels were discussed as a contribution to meeting the challenges of the energy transition to a climate-friendly, sustainable energy economy. One material system with high potential to store and release a large amount of energy is iron powder and its reducible solid product iron oxide powder. In this study, the evolution of the particle morphology during single particle combustion in a laminar flow reactor is analyzed. Partially oxidized iron particles are sampled at different heights above the burner and their internal morphological structure is revealed qualitatively and quantitatively by tomography and microscopy methods (μCT, SEM, EDX, EBSD). The findings show that interfacial phenomena might play a major role when describing single particle combustion as the existence of two liquid phases with emulsification phenomena can be detected. Based on the results, a morphological description of the oxidation progress is proposed within the frame of this work.