Researchers have conducted extensive experimental and theoretical studies on the jamming transition of colloidal and granular suspensions, but the existence and characteristics of jamming transition in nanoparticle-filled polymers remain elusive. In this work, two kinds of polymethylvinylsiloxane/silica nanocomposites were studied. A liquid-solid transition was found at the silica volume fraction of about 5 vol%, corresponding to the percolation of particle agglomerates. At higher silica content (about 10 vol%), a solid-solid transition was found in yield stress, equilibrium modulus, and the contact stress between agglomerates. The characteristic length of the particle network and inter-molecular distance also showed a transition at this transition. This transition corresponds to the simultaneous jamming of particles inside agglomerates and between agglomerates. This bi-level jamming behavior is distinct from the well-known jamming behavior in soft or hard particulate suspensions. Moreover, the dependence of the yield stress and equilibrium modulus on the distance to the jamming concentration differs from the simulations using simple interaction models like harmonic and Hertzian models. It implies that the interfacial viscoelastic layer may offer additional attractive and adhesive interactions between nanoparticles, which is critical in the jamming of polymer nanocomposites.

Soft matters, particularly giant molecular self-assembly, have successfully replicated complex structures previously exclusive to metal alloys. These superlattices are constructed from mesoatoms-supramolecular spherical motifs of aggregated molecules, and the formation of superlattices critically depends on the volume distributions of these mesoatoms. Herein, we introduce two general methods to control volume asymmetry (i.e., the volumes' ratio of the largest to smallest mesoatoms, V-L/V-S) within giant molecular self-assembly. Leveraging the spontaneous increase in the mesoatomic volume ratio in unary systems and self-sorted binary blends, we systematically adjust the volume asymmetry from 1.0 to 9.0 across 24 unary systems and 56 binary blends of giant molecules, uncovering the formation of various superlattices, including BCC, Frank-Kasper A15, sigma, Laves C14, C15, NaZn13, AlB2, and notably, the first NaCl like superlattice in homogeneous soft matter self-assembly. A geometric-based analysis, combined with experimental results, further establishes a quantitative relationship between volume asymmetry and the corresponding superlattice formations, thus laying a solid foundation for superlattice engineering within giant molecular systems to mimic and even beyond metal alloys. The lattice parameters of various unit cells range from approximately 5 to 20 nm. Our investigation in giant molecules could guide the advancement of mesoscopic, periodic soft matter materials.

Injection molding is a polymer-processing method widelyused, whichconsumes about one-third of global plastics and produces 80% of plasticparts. However, it is still challenging to in situ reveal the structuralevolution of polymers during injection molding, which is a long-standingobstacle to understand the relationship of processing-structure-property.This work has first built an in situ investigation system with theaid of a highly brilliant synchrotron X-ray and large experimentalspace with a length of 30 m, width of 8 m, and height of 6 m, allowingthe installation of an industrial-scale injection molding machine.Based on the characterization system, the fast millisecond-resolvedstructural evolution of general semicrystalline polymers is identified.Various structural types of information including crystallizationkinetics, polymorphism, and the growth and orientation of their lamellarcrystals under an actual environment of non-isothermal crystallizationwith a cooling gradient, intense flow, and high pressure during injectionmolding have been revealed for the first time. The high-throughputfeature of the system provides a vital prerequisite for the subsequentestablishment of a quantitative database of processing parameter-structure-performanceand the precise regulation of polymer aggregation structures, whichis valuable for the digitalization and intelligence of the developmentof the injection molding industry and integration into the IndustrialInternet.

Liposomal delivery systems are recognized as efficient and safe platforms for chemotherapeutic agents, with doxorubicin-loaded liposomes being the most representative nanopharmaceuticals. Characterizing the structure of liposomal nanomedicines in high spatial and temporal resolution is critical to analyze and evaluate their stability and efficacy. Small-angle X-ray scattering (SAXS) is a powerful tool increasingly used to investigate liposomal delivery systems. In this study, we chose a Doxil-like PEGylated liposomal doxorubicin (PLD) as an example and characterized the liposomal drug structure using synchrotron SAXS. Classical analytical models, including the spherical-shell or flat-slab geometries with Gaussian or uniform electron density profiles, were used to model the internal structure of the liposomal membrane. A cylinder model was applied to fit the scattering from the drug crystal loaded in the liposomes. The high-resolution structures of the original drug, Caelyx, and a similar research drug prepared in our laboratory were characterized using these analytical models. The structural parameters of PLDs, including the thickness of the liposomal membrane and morphology of the drug crystal, were further compared. The results demonstrated that both spherical-shell and flat-slab geometries with Gaussian electron density distribution were suitable to elucidate the structural features of the liposomal membrane under a certain range of scattering vectors, while models with uniform electron density distribution exhibited poor fitting performance. This study highlights the technical features of SAXS, which provides structural information at the nanoscale for liposomal drugs. The demonstrated methods are reliable and easy-to-use for the structural analysis of liposomal drugs, which are helpful for a broader application of SAXS in the production and regulation of nanopharmaceuticals.

X-ray Raman scattering (XRS) spectroscopy is an emerging inelastic scattering technique used to measure local electronic structure and chemical bonding around low- Z atoms with hard X-rays. This technique is useful in environments where traditional soft X-ray techniques are not applicable. However, the small cross section of XRS requires that the spectrometer must simultaneously achieve large solid angles and good energy resolution. A large XRS spectrometer named `Qian Kun' is currently under construction at the High Energy Photon Source (HEPS) in China, which can hold up to 100 analyzers with an energy resolution in the range 0.4–1.0 eV. Here, the batch production and performance evaluation of the spherically bent crystal analyzers fabricated for this spectrometer are reported. The stress-relief effect of various dicing patterns and their impact on the reflectivity properties of crystal analyzers to achieve good energy resolution when studying the near-edge features of carbon and oxygen K edges were investigated. It was discovered that radially dicing the thin silicon wafers is more effective in relieving stress than conventional strip cuts in the case that the total number of divided blocks is roughly the same.

Characterizing the bulk heterojunction (BHJ) morphology of the active layer is essential for optimizing blade‐coated organic solar cells (OSCs). Here, the morphology evolution of a highly efficient ternary polymer:nonfullerene blend PM6:N3:N2200 under different blade coating conditions is probed in real‐time by in situ synchrotron X‐ray scattering and in situ ultraviolet‐visible (UV‐vis) spectroscopy. Besides, the morphology of blade‐coated blend films at different conditions is detailed by ex situ X‐ray scattering and microscopic imaging. The ternary blend film exhibited optimized morphology, such as superior molecular stacking structure and appropriate phase separation structure, and boosted photovoltaic performance of the binary blend, as adding a second polymer component to the host polymer:nonfullerene system can balance nucleation and crystallization of polymers and small molecules, facilitating molecular rearrangement to perfect crystallization. Both binary and ternary blends obtained optimized morphology and photovoltaic properties at medium coating speed, mainly attributed to the movement of the polymer and small molecules at the long crystallization and aggregation stage. These findings help understand morphology formation under film drying and provide guidance for optimizing the morphology in blade‐coated OSCs.

Understanding the mechanical reinforcement of polymer nanocomposites (PNCs) filled with agglomerated nanofillers has attracted considerable attention in the past century, but a quantitative description of linear rheology over a wide range of time scales is still a challenge at present. In this study, the hierarchical nanofiller structure and its relationship to the rheology of fumed silica-filled poly(methyl methacrylate) nanocomposites are quantitatively investigated using transmission electron microscopy, small-angle X-ray scattering, and rheological measurements. It is suggested that the polymer entanglements dominate the short-time rheological behavior of nanocomposites, and the enhancement in the rubbery modulus is controlled by the interfacial adsorption-induced entanglements, which depend on the effective surface fractal dimension of nanofillers. At a longer time scale, the discrete agglomerates and the particle networks dominate the modulus enhancement. It was found that there is a power-law relationship between the particle network modulus and the inter-agglomerate mesh size with an exponent of -5, corresponding to a chemical dimension of 1 and rigid particle chains. A new two-phase model is suggested for the linear rheology of PNCs, including the contribution of interfacial entanglements, discrete agglomerates, and particle networks. The linear viscoelasticity of PNCs can be quantitatively described using properly determined structural parameters of particle agglomerates.

The precipitation strengthening behavior and its effect on mechanical properties of Al−Mg−Si alloy during isothermal aging were investigated. In-situ synchrotron small angle X-ray scattering (SAXS) technique was used to characterize the nanoprecipitates and their structural parameters (size, volume fraction and number density) combined with transmission electron microscopy (TEM). The results show that rod-shaped β’’ precipitates grow preferentially along their longitudinal dimensions, but the radial dimension reaches a plateau after 5 h of aging. The growth of nanoprecipitates in size and volume fraction is quantitatively related to precipitation strengthening, as shown by predictions and measurements of relevant yield strength and hardness. SAXS provides more reliable input parameters for the Ashby−Orowan model, which improves the predictive accuracy and generalizability of the model. The study demonstrates that with increasing the aging time, the evolution of predictive mechanical properties of Al−Mg−Si alloy is dependent on the mean radius and volume fraction of β’’ precipitates.

In situ synchrotron small-angle X-ray scattering (SAXS) is a powerful tool for studying dynamic processes during material preparation and application. The processing and analysis of large data sets generated from in situ X-ray scattering experiments are often tedious and time consuming. However, data processing software for in situ experiments is relatively rare, especially for grazing-incidence small-angle X-ray scattering (GISAXS). This article presents an opensource software suite (SGTools) to perform data processing and analysis for SAXS and GISAXS experiments. The processing modules in this software include (i) raw data calibration and background correction; (ii) data reduction by multiple methods; (iii) animation generation and intensity mapping for in situ X-ray scattering experiments; and (iv) further data analysis for the sample with an order degree and interface correlation. This article provides the main features and framework of SGTools. The workflow of the software is also elucidated to allow users to develop new features. Three examples are demonstrated to illustrate the use of SGTools for dealing with SAXS and GISAXS data. Finally, the limitations and future features of the software are also discussed.

The packing structures of spherical motifs affect the properties of resultant condensed materials such as in metal alloys. Inspired by the classic metallurgy, developing complex alloy-like packing phases in soft matter (also called "soft alloys") is promising for the next-generation superlattice engineering. Nevertheless, the formation of many alloy-like phases in single-component soft matter is usually thermodynamically unfavourable and technically challenging. Here, we utilize a novel self-sorting assembly approach to tackle this challenge in binary blends of soft matter. Two types of giant shape amphiphiles self-sort to form their discrete spherical motifs, which further simultaneously pack into alloy-like phases. Three unconventional spherical packing phases have been observed in these binary systems, including MgZn2 , NaZn13 , and CaCu5 phases. It's the first time that the CaCu5 phase is experimentally observed in soft matter. This work demonstrates a general approach to constructing unconventional spherical packing phases and other complex superlattices in soft matter.

For those colloidal semiconductor CdSe nanospecies that exhibit sharp optical absorption doublets, different explanations have appeared in the literature regarding their morphological nature and formation, with no consensus reached. Here, we discuss the transformation pathway in two types of CdSe nanoplatelets (NPLs), from NPL-393 to NPL-460, exhibiting absorption doublets at 373/393 and 433/460 nm, respectively. Synchrotron-based small/wide-angle X-ray scattering (SAXS/WAXS) was performed to monitor the in situ transformation associated with the temperature. Combining the results of SAXS/WAXS, optical spectroscopy, and transmission electron microscopy, we propose that the transformation pathway experiences corresponding magic-sized clusters (MSCs), which display similar optical properties but with zero-dimensional structure. From stacked NPL-393 to stacked NPL-460, the transformation goes through sequentially individual NPL-393, MSC-393, MSC-460, and individual NPL-460 at their corresponding characteristic temperature. The present findings provide compelling evidence that both MSCs and their assembled NPLs exhibit similar optical absorption.

In vitro permeation test is an important method to predict permeability of transdermal formulation. We developed a liquid crystal artificial skin membrane (LC ASM) with the combination of hydrophobic polydimethylsiloxane, hydrophilic chitosan network and liquid crystal to mimic the lipid structure, for preliminary in vitro permeation test. The characterization results suggested that polydimethylsiloxane formed the main framework of the artificial skin membrane and it contained crystalline compartment. It has good thermal stability and mechanical strength, with elastic modulus about 0.2-6.2 MPa. The permeation study of model drugs with different polarity, aminopyrine and lidocaine, ketoprofen, flurbiprofen, through the synthetic LC ASMs were carried out. Results indicated that a good correlation of the permeability coefficients between the liquid crystal artificial skin and the human skin permeation tests was obtained. Therefore, it was suggesting that a synthetic artificial skin membrane could be an alternative option for preliminary in vitro permeation test to evaluate of the permeability of drug compounds.

Directed self-assembly of block copolymers (BCPs) is widely investigated for its potential application in surface patterning. The self-assembly kinetics of BCP based on modified layers is the key to realizing structural control for obtaining highly ordered lamellar grains. In this study, morphological evolution of PS-b-PMMA films during the thermal-induced self-assembly process was investigated via the in situ grazing-incidence small-angle X-ray scattering (GISAXS) technique. In the first heating stage, reorientation of lamellar grains occurred as the temperature increased above the glass transition temperature. Then, a fast increase in the lamellar repeat period L0 was observed, which is considered as a phase separation process. Whereas the size of the lamellar grain ξ was observed to have rapidly increased in the stage wherein the temperature was held at 230 °C, the L0 was almost constant. This result indicates that the formation of ordered structure in PS-b-PMMA films was mainly determined by two periods: phase separation of block molecules followed by growth of grains in the nanodomain. In addition, it was interesting that the better-order nanodomains were obtained with thermal annealing at a faster heating rate. These findings suggest that accomplishing ordered structure control in a large area could be realized via the design of a proper heating profile.

Metal alloy superlattices with large volume asymmetry were constructed based on self-sorting assembly of binary giant shape amphiphiles, as reported by Zebin Su, Stephen Z. D. Cheng et al. in their Research Article (DOI: 10.1002/anie.202200637). MgZn2, NaZn13 and CaCu5 superlattices were observed in soft matters, and the thermodynamic origin of their formation was quantitatively analyzed.

The hierarchical self-assembly process opens up great potential for the construction of nanostructural superlattices. Precise regulation of self-assembled superlattices, however, remains a challenge. Even when the primary molecules are precise, the supramolecular motifs (or secondary building blocks) can vary dramatically. In the present work, we propose the concept of unimolecular nanoparticles (UMNPs). The UMNPs act as the supramolecular motif and directly pack into the superlattices. A highly branched giant molecule is presented. We systematically explore its conformations and the superlattice of this giant molecule. Moreover, intriguing complex phases are discovered when blending this UMNP with other conventional giant molecules. These binary mixtures provide direct evidence to support our previously proposed self-sorting process in the self-assembly of "soft alloys". The concept of UMNPs offers a unique approach toward more precise regulation of self-assembled superlattices in soft matter.

The microfocus beam small-angle X-ray scattering (μSAXS) provides a high spatial resolution ability, and the μSAXS/POM simultaneous measurement facilitates the acquisition of the micro-structural variations in the heterogeneous samples. Herein, at the SSRF BL19U2 beamline, a coaxial μSAXS/POM simultaneous measurement system has been established, comprising of the compound refractive lenses and an in-situ polarizing microscope. The SAXS beam size of 5.43 μm × 6.52 μm with a flux of 2.52 × 1011 photons/s has been employed. In order to obtain realistic microstructural information, the visible light path of the polarizing microscope has been set coaxially with the X-ray to eliminate the field of view deviation. The microstructure of the ringed spherulites of the polyoxymethylene/polybutylenesuccinate blends and high-density polyethene (HDPE) fibers has been simultaneously characterized. The differences in the structural information at different positions inside the banded spherulites have been evaluated. The crystallinity of the HDPE fibers increases from the skin to core, whereas the average crystalline lamellae thickness of the HDPE fibers decreases from skin to core, and the long spacing remains almost unchanged in the fibers.

The stretchability and stretch-induced structural evolution of organic solar cells (OSCs) are pivotal for their collapsible, portable, and wearable applications, and they are mainly affected by the complex morphology of active layers. Herein, a highly ductile conjugated polymer P(NDI2OD-T2) is incorporated into the active layers of high-efficiency OSCs based on nonfullerene small molecule acceptors to simultaneously investigate the morphological, mechanical, and photovoltaic properties and structural evolution under stretching of ternary blend films with various acceptor contents. The structural robustness of the blend films is indicated by their stretch-induced structural evolution, which is monitored in real-time by a combination of in situ wide/small angle X-ray scattering. It is found that adding the soft P(NDI2OD-T2) can enhance the stretchability and structural robustness of ternary blend films by more entangled chains and tie chains to dissipate strain. Furthermore, the stretchability of the ternary blends can be superbly predicted by a 3D equivalent box model. This work provides instructive insight and guidance for designing stretchable electronics and predicting the stretchability of multicomponent blends.

Agglomeration and linking of nanoparticles or aggregates lead to the formation of percolated particle networks and alter the mechanical enhancement in polymer nanocomposites. Although critical behaviors have been widely studied, the solidlike behavior is only well described under the condition of the uniform dispersion of nanoparticles. In this work, we illustrate the role of particle-polymer interaction in the uniformity of particle dispersion and mechanical enhancement. Two types of silica with different interfacial adhesion energies with poly(methylvinylsiloxane) were adopted, resulting in different uniformities of particle dispersion. The critical percolation concentrations from the yield shear stress and yield first normal stress difference are identical. A lower interfacial adhesion energy leads to a higher critical concentration. The preshear stress only affects the critical concentration but does not change the critical exponents, which rely on the particle-polymer interaction. The mechanical enhancement, expressed as the power-law dependence of the yield stresses on the filler content, exhibits extraordinarily large power-law exponents for nanocomposites with lower interfacial adhesion energy, seriously deviating from the theoretical prediction in homogeneous dispersion systems. Based on the structural information from small-angle X-ray scattering (SAXS)/ ultrasmall-angle X-ray scattering (USAXS) and transmission electron microscopy (TEM), we propose a model describing the heterogeneous percolation of loose aggregates in the presence of compact aggregates. This model shows that the heterogeneity of aggregates, including the fraction of compact aggregates and their fractal dimension, is the key factor in the scaling relationship between the yield stress and the particle volume fraction.

Exploring the micro structure is of great benefit to the manufacture and application of polymers. Small angle X-ray scattering computed tomography (SAXS-CT), a novel method with ability of nondestructive spatial-resolved, is used to characterize injection molded Poly (butylene adipate-co-terephthalate) (PBAT). The three-dimensional distribution of long period, lamella thickness, amorphous layer thickness and orientation in PBAT made by injection molding have been successfully extracted using the reconstructed voxel scattering. According to the uncovered structure, the bulk PBAT can be clearly divided into three parts as skin, interlayer and core. The lamella thickness shares a distribution in "U" shape while long period, amorphous layer thickness and orientation share a "Swing" shape. More interestingly, a vortex ring inside the PBAT caused by the secondary flow during packing stage in injection molding can be observed via the reconstructed orientation distribution. Here, the internal microstructure and morphology revealed by SAXS-CT can shed a light on the relationship between processing and structure of PBAT.

Fine particulate matter (PM) air pollution has increasingly become a global problem; thus, high-performance air filtration materials are in great demand. Herein, we first prepared a biodegradable hierarchically structured nanocellulose-implanted air filter with a high filtration capacity using a freeze-drying technique. In this hierarchically structured air filter, porous structures of corrugated paper and cellulose nanofibrils (CNFs) were used as a frame and functional fillers, respectively. The self-assembled structure of the CNF fillers could be controlled by changing the freezing temperature, CNF sizes, concentrations, and base weights. Only the CNFs with a smaller size and concentration of 0.05 wt % were able to self-assemble to well-dispersed fibril networks. With constant optimization of conditions, when the base weight went up to only 0.25 g/m2, the coverage of the corrugated paper fibers with CNF networks became perfect, and a high efficiency of 94.6% for PM0.3 removal was achieved, while maintaining a relatively low pressure drop of 174.2 Pa. All of the raw materials we used are biodegradable, nonpetroleum-based materials, contributing to sustainable development. We believe that such excellent biodegradable high-performance cellulose-based air filtration materials will provide a new direction for the application of nanocellulose in air filtration.