Polymer lamellar crystals with highly ordered crystalline structures are ideal systems for understanding and engineering thermally conductive polymers. However, their nanometer-scale thickness, hard-to-eliminate defects, and limited lateral dimensions have impeded experimental characterization, leaving key thermal transport mechanisms unresolved. Here, we address this knowledge gap by devising a multilayer single-crystal stack for a non-contact measurement technique, combined with advanced theoretical calculations. The measured cross-plane thermal conductivity is 4W m-1 K-1 for a 12-nm-thick polyethylene lamellar single crystal, representing the highest value observed for dielectric materials in this thickness range. Theoretical analyses indicate that this value is nevertheless limited by the combined effects from boundary scattering and surface amorphization, offering critical insights for molecular design and understanding of nanoscale heat transfer in ultrathin soft materials.

Liquid crystal-based multiple emulsion carriers for prolonged essential oil delivery: Toward functional antimicrobial fabric finishing.

Hierarchical spherulite structures are ubiquitous in semicrystalline polymers and impact their properties. Elucidating these delicate and complex structures, which span from molecular-level chain folding to mesoscale spherulites, however, presents a formidable challenge. Here, we showcase low-dose four-dimensional (4D) scanning transmission electron microscopy (STEM) as a powerful technique for investigating the multiscale hierarchical structures of polymer spherulites. Applying it to poly(ε-caprolactone) and polyethylene (PE) spherulite films, we reveal the preferential orientation and growth direction of lamellar crystals, as well as the twisted lamella structure in PE banded spherulites. Notably, our observations reveal a non-radial twisting axis forming a spiral texture in PE films. With the enhanced spatial resolution of cryogenic 4D-STEM, we directly visualize individual lamellar crystals at the nanoscale, enabling the identification of chain tilt within a single lamella and the elucidation of lamella configurations at spherulite boundaries. These insights advance our understanding of polymer spherulite crystallization mechanisms and underscore low-dose 4D-STEM as a powerful tool for exploring the intriguing structures of soft materials.

Molecular dynamics simulations are employed to investigate how molecular topology governs the thickness of the interlamellar amorphous layer (La) in semicrystalline polymers. Lamellar crystals with varying initial interlamellar spacing (La0) are seeded in the melt. When La0 falls below twice the radius of gyration of the molecular chain (2Rg), crystal stems exhibit uneven thickening, preferentially extending away from the adjacent lamellae. This leads to a progressive increase of La as the crystal grows. Quantitative analysis reveals significant increases in local entanglement density (Nz) and conformational entropy-derived free energy (Gcon) within the interlamellar amorphous layer, which collectively suppress crystal stem elongation into the constrained layer and direct growth toward the less entangled side. Regardless of the initial La0, systems with identical chain length evolve toward a similar steady-state La. A linear relationship between La and Nz emerges, whose slope corresponds to the entanglement density, which depends solely on the chain length. This reveals that the interlamellar amorphous layer self-adjusts its thickness to maintain a constant entanglement density, which is predetermined by molecular chain length. Our simulations provide molecular-level evidence for how topological entanglements govern the equilibrium morphology of semicrystalline polymers.

In recent years, consumer expectations for effectiveness have been increasing. To address these issues, we used the novel interfacial scientific approaches: liquids with low surface tension, a novel vesicle dispersion using polyglycerol fatty acid esters, which imitated the structure of the cell membrane. The aim is that the vesicle uniformly spreads along the skin surface and makes a larger amount of active ingredients penetrate into the skin. To prepare a vesicle dispersion, research on phase equilibria including a lamellar liquid crystal was carried out. Surface tension and wetting behaviour were checked for the physical property of the system. To identify the skin penetration of active ingredients, tape stripping and human tests were carried out in addition to the imaging of exvivo skin. It was found that a specific OH/C ratio forms lamellar liquid crystals and disperses stably in aqueous dispersion as vesicles. Surface tension of the vesicle dispersion was significantly lower, and the wetting behaviour was more than eight times better than the conventional micellar system. Tape stripping tests revealed that the skin penetration of brightening ingredients was significantly higher than that of the conventional micellar system, of which relevant skin condition was recognized by panellists by a human test. Through this research, we developed a novel, penetrating base system with naturally derived surfactant in which functions work properly for both short and long periods of time after application.

ABSTRACT The effect of deformation on the oriented crystal structure of polypropylene, specializing in capacitor film during stretching at high temperature, was verified. Two kinds of polypropylene with different isotacticity were stretched to different deformation ratios at the same temperature, and the microstructures of the oriented crystals were analyzed by synchrotron 2d wide‐angle/small‐angle X‐ray scattering technique. Results showed that during partial melting stretching, the thickness of lamellar stacks remained constant at a fixed temperature, and the thicknesses of the lamellae crystals, and the amorphous region were invariable over a wide range of stretching deformation. However, the increased deformation led to a decrease in the lateral dimensions of the lamellar stack, indicating that the oriented crystals slipped and broke up along the stretch direction, resulting in the formation of microfibrillar structures. This increase was accompanied by an increase in crystal orientation induced by external forces. Additionally, higher isotacticity facilitated the acquisition of a high degree of orientation and crystallinity, but it had less effect on the lamellar stack thickness. This paper elucidated the relationship between the oriented crystal structure and the deformation behavior of polypropylene, thereby providing a fundamental theoretical basis for optimizing the properties of films based on the hot‐stretching process.

A new homologous series of mesogenic compounds with nearly linear mesogenic cores was studied, and it showed a strong discrimination between nematic and smectic phases with respect to the length of the terminal chain. For short homologues a ferroelectric nematic, NF and a heliconical nematic, NTBF phases were observed, while for longer ones they were replaced with ferroelectric smectic AF and CF phases. The n = 3 homologue exhibits a unique sequence of SmCF and its heliconical analogue SmCHP. Replacing an alkyne linkage in the mesogenic core with an alkene one favoured smectic phases and led to the appearance of a modulated-type SmAAF phase.

Abstract Samples returned from asteroid Ryugu by the Hayabusa2 mission are dominated by fine‐grained matrix material made of phyllosilicates and nanosulfides. Here, we report the mineralogical, textural, and chemical characteristics of nanosulfide‐rich regions identified in Ryugu particles. High‐resolution scanning transmission electron microscopy and energy‐dispersive X‐ray spectroscopy reveal nanoscale heterogeneities in sulfide composition and morphology, indicating formation under variable conditions. Nanosulfide‐rich regions are dominated by the presence of mackinawite (FeS) and pyrrhotite (Fe 1‐ x S), in different proportions. Mackinawite, identified for the first time in Ryugu, occurs as well‐crystallized lamellar crystals with some areas containing greigite (Fe 3 S 4 ) and others showing signs of oxidation. In contrast, pyrrhotite appears either as euhedral nanocrystals or as structurally complex grains composed of stacked platy segments, which are characterized by numerous defects, including inclusions and planar defects. The distribution and associations of these phases are consistent with low‐temperature aqueous alteration under alkaline and reducing conditions, likely occurring in Ryugu's parent body. The presence of mackinawite implies complex thermodynamic and kinetic constraints and suggests the presence of localized fluids in which Fe concentrations exceeded those of S by an order of magnitude.

Impact of oil unsaturation on crystalline particles and self-assembled fiber oleogels: Physicochemical properties, crystallinity, and potential mechanism.

Polyglycolic acid (PGA), a biodegradable polymer with many potential applications, is primarily synthesized via the ring-opening polymerization of glycolide monomers. Here, the temperature sensitivity of the PGA crystallization kinetics is systematically analyzed using differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). Regression analysis yields Avrami exponents (n) within the range 1.41-1.51, indicating that PGA forms lamellar crystals during crystallization from heterogeneous nucleation. The FTIR indicates that the PGA molecular chains alter their conformation during crystallization. XRD reveals that the crystallization rate and crystallinity of PGA closely correlate with the processing temperature. The heterogeneous nucleation of PGA can be optimized by incorporating suitable nucleating agents or regulating the surface roughness to improve the crystallization rate and quality. Polarized optical microscopy (POM) indicates that elevated temperatures increase the polymer chain mobility and free growth of crystallization nuclei, whereas lower temperatures promote the rapid formation of crystallization nuclei but impede growth. Graphene oxide (GO) has abundant surface functional groups, is an efficient heterogeneous nucleating agent, and promotes molecular chain alignment to increase both the crystallization rate and crystallinity. This GO-induced enhancement demonstrates a promising strategy for tailoring the thermal and mechanical properties of PGA for advanced biomedical applications.

Marinaite, ideally Cu 2 Fe 3+ O 2 (BO 3 ), a new mineral, was found in a high-temperature (400-600C) crack on the cooling lava field of the 2012-2013 fissure eruption at Tolbachik volcano, Kamchatka, Russia.The associated minerals are belomarinaite, tenorite, hematite, anglesite and gold.Marinaite forms prismatic, tabular, lamellar or acicular crystals up to 0.06 x 0.06 x 0.3 mm or aggregates of these forms up to 3 mm across.The mineral has a brown to black colour and submetallic lustre.Under the microscope in reflected light marinaite is grey with reddish-brown internal reflections.D calc .=5.026 g/cm 3 .Electron microprobe analyses yielded (wt.%) 62.15 CuO, 16.71 Fe 2 O 3 , 5.11 Al 2 O 3 , 3.14 TiO 2 , 0.16 SiO 2 , 12.84 B 2 O 3 , total 100.11wt.%.The empirical formula calculated based on 5 O apfu is Cu 2.07 Fe 0.56 Al 0.27 Ti 0.10 Si 0.01 B 0.98 O 5 .Marinaite is monoclinic, space group P2 1 /c, unit-cell parameters are: a = 3.12750(18), b = 11.9690(8),c = 9.4657(5) , = 97.568(6),V = 351.24(4) 3 and Z=4.The strongest lines of the powder XRD pattern [d in (I)(hkl)] are: 5.

Semicrystalline polymers with multiple crystallizable blocks provide opportunities to develop materials with hierarchical structures and customized properties, but they also pose unique challenges for understanding their crystallization. In this work, we investigate the crystallization from a miscible melt of a pentablock quintopolymer composed of five potentially crystallizable and biocompatible blocks, composed of polyethylene (PE), poly(ethylene oxide) (PEO), poly(ε-caprolactone) (PCL), poly(L-lactide) (PLLA), and polyglycolide (PGA), with a composition optimized to allow the crystallization of all blocks. Using Differential Scanning Calorimetry, synchrotron Fourier Transform Infrared Spectroscopy, synchrotron in situ Wide-angle and Small-angle X-Ray Scattering, Transmission Electron Microscopy, and Polarized Light Optical Microscopy, we demonstrate that upon cooling from the melt, all covalently linked blocks crystallize in a well-defined sequence: PGA > PLLA > PE > PCL > PEO. During crystallization, well-developed pentacrystalline positive spherulites are produced. This unprecedented level of self-assembly reveals the potential of complex block polymers to design multifunctional crystalline materials.

TiAl alloys are widely used in aerospace applications due to their low density and good mechanical properties. However, their pronounced mechanical anisotropy resulting from the preferred orientations of lamellar crystals remains an important issue. This study investigates the plastic anisotropy of TiAl alloys under various stress states using full-field crystal plasticity modeling based on electron backscatter diffraction data. The crystal plasticity simulations successfully reproduce the experimental mechanical anisotropy in uniaxial and biaxial tests. The research combines crystal plasticity simulations with Yld2004-18p anisotropic yield function to develop a predictive model that accurately characterizes the anisotropic yielding behavior of the TiAl alloys under various stress states. The findings demonstrate that the Yld2004-18p anisotropic yield function effectively describes the macroscopic anisotropic response obtained from crystal plasticity simulations, providing an important theoretical foundation for predicting the anisotropic behavior of TiAl alloys in engineering structures.

Engineered manganese phosphate coatings on titanium implants: synergistic photothermal antibiosis and ion-stimulated osteogenesis via zinc/calcium co-doping

ABSTRACTThe incorporation of nanofillers into biodegradable polymers is an effective approach to improve the physical properties and mechanical performance for various practical applications. In particular, the interfacial microstructure between the polymer and nanofillers plays a critical role in determining the macroscopic properties of the resulting polymer nanocomposite. In this work, we report carbon nanotube (CNT) induced interfacial transcrystallization of poly(L‐lactic acid) (PLLA) in the single‐fiber composite. The dynamic process of PLLA transcrystallization around the single CNT fiber is investigated under isothermal crystallization in the temperature range from 124°C to 136°C using in situ polarized optical microscopy. Transcrystallization kinetics are analyzed based on polymer heterogeneous nucleation and crystallization theories. The interfacial free energy difference parameter (Δσ/σ = 0.057) and the fold surface free energy (σe = 5.82 × 10−2 J/m2) are calculated to assess the nucleation ability and crystallization barrier, respectively. Atomic force microscope (AFM) analysis reveals radially aligned edge‐on lamellar crystals adjacent to the CNT fiber. Alternative transformation from the edge‐on lamellar orientation to a flat‐on orientation results in a banded transcrystalline texture. A proposed mechanism is presented that lamellar twisting during the crystal growth is attributed to the banded transcrystals.

Achieving the self‐assembly of lamellar liquid crystals (LLCs) at sub‐zero temperatures and elucidating their structure‐assembly interplay are crucial for understanding cryobiological processes and facilitating cryogenic soft materials; however, this remains a formidable challenge. Herein, six alkyl alkanolamide amphiphiles are designed, and their self‐assembly behavior in 1,2‐propanediol/water cosolvent is investigated from 80 to −20 °C. The hydrocarbon chain length exerts a significant influence on self‐assembly behavior at both short‐range and long‐range scales. Amphiphiles with hydrocarbon chains shorter than C16 (i.e., the number of carbon atom is 16) exhibit limited solubility and cannot form LLCs at low temperatures, while longer chains enhance cryo‐solubility and self‐assembly capabilities, contradicting conventional assumptions. Notably, amphiphiles with chains of C18 or longer require only 0.3 wt.% for LLCs formation. These LLCs exhibit intriguing temperature‐dependent phase transitions, including a liquid‐like lamellar phase, a tilted gel phase, and a distinct phase characterized by tighter alkyl chain packing. The hydrocarbon chain length directly governs the transition temperatures and further influences the long‐range orientational ordering of lamellar sheets. Additionally, the tightly‐packed configuration confers exceptional rheological properties, including ultra‐high viscosity, shear‐thinning behavior, and elasticity. These findings provide important insights for the design and engineering of high‐performance soft materials used in extreme environments.

Deep eutectic solvents (DESs) are relatively promising green solvents due to their low toxicity, high stability, and tunable structures. Despite their advantages, research on G-quadruplex ionic soft materials based on DESs remains scarce. Herein, we report the construction of G-quadruplex lamellar liquid crystals in DESs, specifically in choline chloride-ethylene glycol (ChCl-EG) mixtures. Our study may develop a solvent-mediated strategy and elucidate a formation mechanism driven by the oriented arrangement of solvent molecules, which plays a crucial role in the formation of lamellar structures. Dynamic borate esters were found to weaken inter-G-quadruplex interactions while enhancing G-quadruplex-solvent interactions. We investigated the effects of metal ions (K+, Na+, Ca2+, Sr2+, and Ba2+) and reactant concentrations on G-quadruplex assembly, revealing that metal ions control the stacking mode and regulate the mechanical properties of the resulting gels. The G-quadruplex lamellar liquid crystal exhibited high ionic conductivity (4.6 mS·cm-1) and a wide electrochemical window (4.6 V). This work may advance the understanding of the G-quadruplex, establish DESs as versatile platforms for designing ionic soft materials, and open new avenues for applications in flexible electronics and energy storage.

Manipulating polymer crystallization behavior and structure without altering chemical composition remains a core challenge in polymer crystallography. Molecular weight, as an intrinsic material property, governs the crystallization process from nucleation through growth. Synthetic polymer materials exhibit molecular weight distribution (MWD), resulting in polydisperse polymer chains within one system. This MWD drives distinct crystalline structures, whereas synergistic crystallization behaviors arise among chains of various lengths. MWD yields complex crystallization behaviors. Especially, spatial molecular weight distribution induces novel crystalline textures in polymer materials. Elucidating the crystallization mechanisms is vital for understanding structure-property relationships in polymers. Herein, the recent advances in the various influences of MWD on polymer crystal textures are systematically demonstrated.

Biobased polyesters, recyclable sustainable polymersderived fromrenewable feedstock, are promising alternatives to petroleum-basedpolymers. The crystallization behavior, crystal structure, and supramolecularstructures of a series of biobased long-chain aliphatic polyesters,consisting of a diester of 10-undecenoic acid with isosorbide (IS),isomannide (IM), and butanediol (BD) as the midsegments, were studiedby various scattering methods and Raman spectroscopy. Polyesters containingbutanediol-type midsegments (C18BD) participated in thecrystallization by being incorporated into the orthorhombic polyethylenecrystal lamellae. The polyesters containing isosorbide- and isomannide-typemidsegments (C18IS, C18IM) were excluded fromthe crystal lamellae and inhibited the formation of orthorhombic crystals;the lamellar thickness was thus determined by the length of the methylenechains between the midsegments. An introduction of these midsegments(IS, IM) led to formation of some loose structures even in the moltenstate; acceleration of the nucleation led to a heterogeneous nucleation-likecrystallization behavior, and the final spherulite size was finer.

Rational design of planar lamellar energetic crystals via intermolecular interaction engineering: Synergistic mechanisms for balancing energy and safety