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The self-assembly of polymeric micelles and colloidal dispersions into intricate structures represents a transformative approach in contrast to traditional fabrication methods for creating new functional materials. Despite remarkable advancements in the field, there exists substantial potential for further progress. In the past two decades, scientists have innovated and applied sophisticated methods for synthesizing nanocrystals of diverse geometries and polymeric materials with varying molecular characteristics. These synthetic pathways play a pivotal role in the facile fabrication of a multitude of nanostructures, which also greatly facilitates our understanding of the governing principles of meso and nano object self-assembly. This review focuses on the complex packing structures of block copolymer micelles and colloidal particles, with a particular emphasis on the Frank-Kasper phase. A comprehensive exploration of the recent theoretical and experimental advances in this interdisciplinary field is presented. By drawing parallels between the self-organized formation of both hard particles and soft micelles, this review aims to provide a fundamental understanding of the underlying physics and chemistry that contribute to the emergence of complex packing behavior. This knowledge is instrumental in the design and engineering of structures tailored to specific applications, fostering further innovation in the realm of nanomaterials. [ABSTRACT FROM AUTHOR]

An innovative strategy is presented that incorporates deep auto‐encoder networks into a least‐squares fitting framework to address the potential inversion problem in small‐angle scattering. To evaluate the performance of the proposed approach, a detailed case study focusing on charged colloidal suspensions was carried out. The results clearly indicate that a deep learning solution offers a reliable and quantitative method for studying molecular interactions. The approach surpasses existing deterministic approaches with respect to both numerical accuracy and computational efficiency. Overall, this work demonstrates the potential of deep learning techniques in tackling complex problems in soft‐matter structures and beyond. [ABSTRACT FROM AUTHOR]

We outline a machine learning strategy for quantitively determining the conformation of AB-type diblock copolymers with excluded volume effects using small angle scattering. Complemented by computer simulations, a correlation matrix connecting conformations of different copolymers according to their scattering features is established on the mathematical framework of a Gaussian process, a multivariate extension of the familiar univariate Gaussian distribution. We show that the relevant conformational characteristics of copolymers can be probabilistically inferred from their coherent scattering cross sections without any restriction imposed by model assumptions. This work not only facilitates the quantitative structural analysis of copolymer solutions but also provides the reliable benchmarking for the related theoretical development of scattering functions. [ABSTRACT FROM AUTHOR]

The formation of distorted lamellar phases, distinguished by their arrangement of crumpled, stacked layers, is frequently accompanied by the disruption of long-range order, leading to the formation of interconnected network structures commonly observed in the sponge phase. Nevertheless, traditional scattering functions grounded in deterministic modeling fall short of fully representing these intricate structural characteristics. Our hypothesis posits that a deep learning method, in conjunction with the generalized leveled wave approach used for describing structural features of distorted lamellar phases, can quantitatively unveil the inherent spatial correlations within these phases. This report outlines a novel strategy that integrates convolutional neural networks and variational autoencoders, supported by stochastically generated density fluctuations, into a regression analysis framework for extracting structural features of distorted lamellar phases from small angle neutron scattering data. To evaluate the efficacy of our proposed approach, we conducted computational accuracy assessments and applied it to the analysis of experimentally measured small angle neutron scattering spectra of AOT surfactant solutions, a frequently studied lamellar system. The findings unambiguously demonstrate that deep learning provides a dependable and quantitative approach for investigating the morphology of wide variations of distorted lamellar phases. It is adaptable for deciphering structures from the lamellar to sponge phase including intermediate structures exhibiting fused topological features. This research highlights the effectiveness of deep learning methods in tackling complex issues in the field of soft matter structural analysis and beyond. [ABSTRACT FROM AUTHOR]

Exact graft copolymer (EGC) is a type of copolymer with precisely defined molecular parameters, including the number of grafts per molecule ( n), the length of the grafts ( lg), and the separation distance between the junction points (ε) in the backbone. In the present study, the phase structure of the EGC composed of poly(2-vinyl pyridine) backbone and polystyrene graft with n = 2 and n = 3 under fixed ε and lg is systematically investigated to seek a general understanding on the effect of the graft architecture on the domain spacing of the microphase-separated structure and the order-disorder transition temperature ( TODT). It is found that the TODT associated with the fluctuation-induced ODT of the EGC increases with increasing n due to the increase of the total molecular weight. Nevertheless, the domain spacing does not exhibit a monotonic change with n, as the EGC with n = 2 shows the largest domain spacing compared with that of EGC with n = 3 and the corresponding linear diblock copolymer. The experimental observation on the domain spacing is explained by a thermodynamic model considering the packing mode of the constituting chains under the junction constraint. [ABSTRACT FROM AUTHOR]

Alternative approaches to treating subcutaneous abscesses-especially those associated with antibiotic-resistant pathogenic bacterial strains-that eliminate the need for antibiotics are urgently needed. This work descibes a chitosan (CS) derivative with self-doped polyaniline (PANI) side chains that can self-assemble into micelles in an aqueous environment and be transformed into colloidal gels in a process that is driven by a local increase in pH. These self-doped PANI micelles can be utilized as nano-localized heat sources, remotely controllable using near-infrared (NIR) light. To test the in vivo efficacy of the CS derivative as a photothermal agent, an aqueous solution thereof is directly injected at the site of infected abscesses in a mouse model. The injected polymer solution eventually becomes distributed over the acidic abscesses, forming colloidal gels when it meets the boundaries of healthy tissues. After treatment with an 808 nm laser, the colloidal gels convert NIR light into heat, causing the thermal lysis of bacteria and repairing the infected wound without leaving residual implanted materials. This approach has marked potential because it can provide colloidal gels with tunable spatial stability, limiting localized heating to the infected sites, and reducing thermal damage to the surrounding healthy tissues. [ABSTRACT FROM AUTHOR]

Abstract: Low polydispersity linear and cyclic poly(ε-caprolactone) with molecular weights of 2–7.5 kg/mol were synthesized. Differences in the morphology of cyclic and linear single crystals (obtained from solution at identical temperatures) indicate that cyclic PCL crystals were obtained at higher supercoolings than linear ones. Cyclic PCL crystals (both crystallized from solution and from the melt) exhibited higher melting point values (T m ) than analogous linear PCL lamellae. In addition, cyclic PCLs crystallize from the melt at higher rates than linear PCLs at identical crystallization temperatures. Results showed that cyclic PCLs possess a higher equilibrium melting point () than linear PCL crystals. A modified Thomson–Gibbs equation and a modified Hoffman–Weeks equation have been derived in this work to demonstrate that the higher of the cyclic polymer stemmed from the negative cyclization entropy associated with the absence of chain ends and the more collapsed conformation of the cyclic chain in the melt state. [Copyright &y& Elsevier]

We investigate the crystallization behavior of isotacticpolypropylene(iPP) under the influence of nanoscale confinement templated by themicrophase-separated structure of an iPP-based diblock copolymer system,isotactic polypropylene-block-atactic polystyrene(iPP-b-aPS). Three types of iPP microdomains, i.e.,lamellae, cylinder, and sphere, were generated by controlling thecomposition of the diblock. The effect of microdomain morphology onthe nucleation mechanism, crystallization kinetics, self-nucleationbehavior, the population of the helical sequence of iPP block in themelt state, and crystal orientation have been systematically studied.It was found that the crystallization rate of iPP was predominantlycontrolled by homogeneous nucleation when the crystallization processwas largely confined within the individual cylindrical and sphericalmicrodomains. Such a nucleation mechanism and the highly frustratedcrystal growth in the isolated microdomains led to the absence ofDomain II and atypical crystallization kinetics in Domain III in theself-nucleation study. The population of the longer helical sequenceof iPP block revealed by infrared spectroscopy was found to be affectedby temperature but not by the spatial confinement, chain stretching,and junction point constraint imposed by the microdomains. Finally,the orientation of α-form iPP crystals in the lamellae-formingiPP-b-aPS was identified over a broad range of crystallizationtemperatures (Tc). Different from othercrystalline–amorphous diblocks, a lamellar branching of α-formiPP was observed in the lamellar microdomains at Tclying between 15 and 80 °C, where the daughterlamellae developed from the perpendicularly orientated parent iPPcrystals with a specific angle of 80° or 100°. Once thesample was crystallized at Tc≤10 °C, the iPP crystals became randomly oriented. [ABSTRACT FROM AUTHOR]

The crystallization kinetics and crystallization-inducedmorphologicalformation of an asymmetric double-crystalline block copolymer, syndiotacticpolypropylene-block-poly(ε-caprolactone) (sPP-b-PCL), have been investigated by time-resolved simultaneoussmall-angle and wide-angle X-ray scattering (SAXS/WAXS). The sPP-b-PCL under study exhibited hexagonally packed cylindermorphology in the melt state, where the minority sPP block formedthe cylindrical microdomains dispersed in the PCL matrix. The crystallizationbehavior was studied by imposing two types of crystallization histories:(1) two-stage crystallization, where the diblock was first cooledto the temperature TcsPPsituatingbetween the melting points of the two components (TmPCL< TcsPP< TmsPP) to allowsPP crystallization to saturation followed by cooling to TcPCL< TmPCLto induce PCL crystallization; (2) one-stage crystallization,where the system was cooled directly to Tc< TmPCLto allow the twocomponents to crystallize competitively. In both cases, the crystallizationof sPP block was in general able to disrupt the melt structure andtransformed it into a crystalline lamellar morphology. For the two-stagecrystallization process, the PCL block was found to exhibit a fastercrystallization at a given TcPCLwhen the sPP block was precrystallized at higher TcsPP. This “interactive crystallizationkinetics” was attributed to the mediation of the stretchingof PCL blocks by the thickness of sPP crystalline domains which dependedon TcsPP. In the one-stageprocess, the crystallization events of the two blocks became morecompetitive with decreasing Tc. The morphologicalperturbation induced by crystallization was also more hindered atlower Tc, such that a significant portionof sPP blocks remained confined within the cylindrical microdomainsso as to suppress the sPP crystallinity. [ABSTRACT FROM AUTHOR]

Abstract: By means of chemical modification, flexible branched alkoxy chains were successfully attached to the para-site of the side phenyl groups of DP-PPV to obtain a new soluble fully conjugated PPV, named poly(2,3-di-[p-(2′-ethylhexoxy)phenyl]-1,4-phenylenevinylene). Spectroscopic characterizations using UV, photoluminescence (PL) and photoluminescent excitation (PLE) showed only the emission of single chromophore of this polymer in the solution state, indicating that the solubility of poly(2,3-diphenyl-1,4-phenylene vinylene) (DP-PPV) was significantly improved by attaching the alkoxy side chains. In the spin-coated film, the emission of the single chromophore with longer conjugating length was observed. In addition, the spectral feature showed the absence of the emission from the aggregate, which was usually observed in the alkoxy-modified PPV, revealing that the polymer chains were well-separated by the side chains. The performance of the single-layer ITO/PEDOT/p-EHDP-PPV/Ca/Al LED device was also reported. The maximum luminescence and efficiency at 11V was 3735Cd/m2 and 0.57Cd/A, respectively. [Copyright &y& Elsevier]

Understanding the thermal aging kinetics of animal oils is of vital importance in the storage and applications of animal oils. In this work, we use four different techniques, including UV-Vis spectrometry, viscometry, impedance spectroscopy, and acid–base titration, to study the thermal aging kinetics of tallow, chicken oil, lard, and sheep oil in the temperature range from 120 °C to 180 °C. The evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration are discussed with the defect kinetics. The evolutions of the color centers, defects for dynamic viscosity, and electric dipoles follow second-order, first-order, and zero-order kinetics, respectively. The temperature dependence of rate constants for the evolutions of the UV-Vis absorbance, dynamic viscosity, electric impedance, and acid titration satisfies the Arrhenius equation with the same activation energy for individual animal oils. The activation energies are ~43.1, ~23.8, ~39.1, and ~37.5 kJ/mol for tallow, chicken oil, lard, and sheep oil, respectively. The thermal aging kinetics of the animal oils are attributed to the oxidation of triglycerides. [ABSTRACT FROM AUTHOR]

A novel graded‐HOMO‐level hole transport polymer (g‐HTP) is proposed for the first time with spiro‐polyfluorene (sPF) as the main chain and the three hole‐transporting moieties triphenyl amine (TPA), carbazole (Cz), and N,N′‐dicarbazolyl‐3,5‐benzene (mCP) as side chains for effective hole injection across the large barrier 1.4 eV into the green‐emission core–shell quantum dot (QD) CdSe/ZnS emission layer in inverted QD light‐emitting diode (i‐QLED): ITO/ZnO/QD/HTP/MoO3/Al, in which both oleophilic ligands (OA and TOP) in the QD are partially removed from QD surface by annealing at 270 °C for preventing dissolution by solvent in subsequent coating of hole transport material (HTM) solutions atop and also improving electron and hole mobilities, especially the former. The proposed g‐HTP with various m:n mole ratios of mCP to TPA/Cz moieties along with various reported HTMs (PVK, Poly‐TPD and TFB) are investigated. Among them, the proposed g‐HTP with the comonomer mole ratio 1:1 gives the best performance ηmax 36.1 cd A−1 and Bmax 208 600 cd m−2, which is the highest performance among the reported i‐QLEDs with single hole‐transport layer ever documented. In addition, its efficiency roll off is low from 35.8 cd A−1 at 10 000 cd m−2 to 31.1 cd A−1 at 100 000 cd m−2. [ABSTRACT FROM AUTHOR]

Composites of nanosized CdS–ZnS core–shell particles well dispersed in polycetyl- p-vinylbenzyldimethylammonium chloride (PCVDAC) were fabricated and their optical properties and morphology were studied. The core-shell particles of less than 10 nm in size were prepared with the reverse micellar solutions formed by a polymerizable anionic surfactant, CVDAC, and a direct thermal radical polymerization of the micellar solution led to the nanocomposite containing well-dispersed core–shell particles. The shell was inferred from small angle x-ray scattering to be around a monolayer thick. This monolayer coating, however, was enough to produce an appreciable enhancement in photoluminescence for the ZnS-coated CdS system (wider band gap material on narrower band gap material), and a degradation in photoluminescence for the CdS-coated ZnS system. However, a complete coverage of the CdS core with ZnS was required to realize the photoluminescence enhancement for the ZnS-coated CdS system. The polymer domains in the composite were found to be composed of lamellar stacks due to the comb-like structure of PCVDAC. The interlamellar distance was 3.9 nm with smectic liquid crystalline texture observed under polarized optical microscope. The core–shell particles were believed to locate at the grain boundary of the liquid crystalline domains. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Abstract Long-chain branched polyethylene terephthalates (PETs) composed of ethylene glycol, terephthalic acid, trimesic acid, and their biaxially stretching films with superior crystal sizes and inferior crystal growth rates, melting points, equilibrium melting points, fold surface free energies, and orientation parameters compared to common PET were manufactured by T-Die extrusion and biaxially stretching treatment. In order to evaluate the hydrolysis resistance for biaxially stretching films of lab-made long-chain branched PETs, we examined their half-life period of elongation, defined as the time for which the films could retain their elongation at 50% during the hydrolysis procedure under conditions of 100% humidity, 1.5 atm pressure and 120 °C. Experimental results revealed that biaxially stretching film of long-chain branched PET II had high potential as an optical substrate for optoelectronic devices because its half-life period of elongation was 58 compared to 21 h for common PET. Highlights • Long-chain branched PETs and their biaxially stretching films were manufactured. • The lab-made PET films exhibit superior T m , T m °, σ e , and P 2 compared to common PET. • Lab-made PET films have high potential in optoelectronic devices due to high hydrolysis resistance. [ABSTRACT FROM AUTHOR]

Spherical micelles formed by block copolymers (bcps) are soft colloids capable of packing into three-dimensionally ordered lattice. Although close-packed sphere structure has been predicted to exist over a narrow region in the phase diagram, it remains unclear whether face-centered cubic (FCC) or hexagonal close packed (HCP) lattice is the stable close packing symmetry for the crystallographically equivalent bcp micelles, as they are essentially degenerated. The present study explores the lattice structure organized by the spherical micelles in bcp/homopolymer blends after erasing the solvent history involved in the blend preparation. The facts that the FCC structure developed in the solvent-cast blend transformed into HCP on heating and HCP phase was formed upon cooling from the disordered micelle phase attest that HCP was the favored close-packed lattice over FCC. The better thermodynamic stability of HCP phase was attributed to the more extensive connectivity of the octahedron voids in the lattice, which prescribed a higher overall translational entropy of the homopolymer chains localized in the voids for space filling. Image 1 • Spherical micelles formed by block copolymers can pack into 3D ordered lattice. • FCC and HCP are the two generic types of close-packed lattices. • HCP is favored over FCC for micelles formed by block copolymer/homopolymer blend. • Connectivity of octahedron voids in lattice prescribes the better stability of HCP. [ABSTRACT FROM AUTHOR]

Abstract A photosensitive polyimide (PSPI) with high glass transition temperature (T g ; 259 ℃), good inherent viscosity (I.V.; 0.31 dL/g), and superb decomposition temperature (T d ; 368 ℃) has been manufactured by the appropriate prescription of diamine monomer (i.e. 2,2-bis (3-amino-4- hydroxyphenyl)-hexafluoropropane; APAF), dianhydride monomer (i.e. 4,4′-(4,4′- isopropylidenediphenoxy)bis(phthalic anhydride); BPADA), cyclodehydating agent (i.e. p -xylene), base (i.e. N,N,N-triethylamine; TEA), and photosensitive monomer (i.e. acryloyl chloride; AOC). In order to explore the applying feasibility, we have prepared lithographic insulation pattern resin (LIPR) of integrated circuit (IC) with PSPI (i.e. APAF/BPADA/AOC polyimide), solvent (i.e. N-methyl-2-pyrrolidone; NMP), photoinitiator (i.e. I-305), crosslinking agent (i.e. CLA-1), co-photoinitiator (i.e. I-309) as well as coupling agent (i.e. vinyltrimethoxysilane; VTES) and utilized it without negative photoreist by silicon wafer, i-line (wavelength: 365 nm; optical density: 1200 mW/cm2), and photomask. Experimental results reveal that lab-made LIPR of IC based on PSPI is a promising IC package material with high tensile strength of 106 MPa, excellent adhesion on silicon wafer (i.e. eligible of cross-cut examination), great coefficient of thermal expansion (CTE) of 17.9 ppm/℃, low dielectric constant (D k ) of 3.5, high surface electric resistance of 8.3 × 1011 Ω/sq., low dielectric loss (D f ) of 0.01, moderate hygroscopicity of 2.9% (23 ℃, 24 h), and low residual stress of 32.0 MPa. [ABSTRACT FROM AUTHOR]

On page 721 Y. Chang, H.‐W. Sung, and co‐workers report an injectable polymer solution that exhibits a rapid nanostructural transformation into colloidal hydrogels within a narrow pH range. The transformation spreads over the acidic area of an abscess without overflowing onto a healthy tissue, providing tunable spatial stabilization. The colloidal hydrogels can accordingly convert NIR light into localized heat, leading to the thermal lysis of bacteria and repairing the infected wound without residual implanted materials left. [ABSTRACT FROM AUTHOR]

SrAl 2 O 4 :Eu is a known ML phosphor. The material was successfully synthesized using combustion method, downsized to different particle-size ranges (from microcrystalline to nanocrystalline sizes) through ball milling. It was further annealed at different high temperatures (200–800 °C) and characterized by XRD and FESEM. Reorganization of the material from SrAl 2 O 4 (monoclinic, space group P2 1 /c) to Sr 2 Al 6 O 11 (orthorhombic, space group Pnnm) plus SrO (cubic, space group Fm 3 ̅ m) phases on annealing above 800 °C was observed. ML studies show that the electron traps lost during mechanical/thermal stimulation could be regenerated by UV-irradiation. This property of the material was explored here to estimate the doses of UV radiations (UV-A, B and C). Also, dose responses of the materials having different particle size ranges from microcrystalline to nanocrystalline sizes were studied and found that the dose ranges get widened with the particle size decreasing with little sacrifice of the sensitivity. Thus, very high doses of the UV-radiation could also be estimated using ML nanophosphors. Fading at room temperature was little high but remaining ML is good enough for the dosimetry purpose. To the best of our knowledge such kind of detailed study on dosimetry of UV-radiations using ML technique is not found in the literature. It was also found that this material did not yield any ML after annealing the material above 800 °C and even after UV-irradiation. It was further explored by annealing the material in reducing and oxidizing atmospheres that whether it is due to the phase transitions or redox reactions. [Display omitted] • Different phases, i.e., Sr 2 Al 6 O 11 (Orthorhombic) and SrO (Cubic) and SrAl 2 O 4 (Monoclinic) identified on annealing above 800 °C for 1.0 h in air. • The variation of the ML intensity with particle size, i.e., decrease in ML intensity with particle size decreasing is important for applications. • Regeneration of traps/luminescence recombination centers (LRCs)/ML by UV light is important for UV dosimetry using ML technique • The material (SAOE) is reusable on annealing at 800 °C in a reducing (10% H 2 in Ar) atmosphere, i.e., the lost traps/LRCs/ML could be regenerated. • A model based on defects and redox reactions explaining regeneration, sensitization and quenching has been proposed. [ABSTRACT FROM AUTHOR]

Polymer crystallites may exhibitpreferred orientation when thecrystallization is allowed to occur under the influence of spatialconfinement. Using time-resolved wide-angle X-ray scattering (WAXS),we explore the time evolution of the preferred crystal orientationwithin one-dimensionally confined space constructed by the lamellarmicrodomains of two crystalline block copolymers, polyethylene-block-poly(dl-lactide) (PE-b-PDLLA) and poly(l-lactide)-block-polyethylene(PLLA-b-PE), where the developments of the paralleland the perpendicular orientation of PE and PLLA crystallites, respectively,were monitored from the early stage of crystallization. Both typesof crystallites were randomly oriented at the early stage of formation.As crystallization proceeded further, the ensemble-average orientationprogressively improved toward the preferred orientation type, andthe rate of establishing the orientation exhibited the same dependenceon crystallization temperature (Tc) asthe crystallization kinetics. Further examination of the effectivenessof enhancing the average orientation with respect to the increaseof crystallinity supported the postulate that the perpendicular orientationof PLLA crystallites arises from the tendency to attain long-rangecrystal growth, while the parallel crystal orientation of PE is drivenby the excluded volume interaction between the crystallites as a resultof the intrinsically high nucleating power of PE. [ABSTRACT FROM AUTHOR]

Repeated cancer treatments are common, owing to the aggressive and resistant nature of tumors. This work presents a chitosan (CS) derivative that contains self-doped polyaniline (PANI) side chains, capable of self-assembling to form micelles and then transforming into hydrogels driven by a local change in pH. Analysis results of small-angle X-ray scattering indicate that the sol–gel transition of this CS derivative may provide the mechanical integrity to maintain its spatial stability in the microenvironment of solid tumors. The micelles formed in the CS hydrogel function as nanoscaled heating sources upon exposure to near-infrared light, thereby enabling the selective killing of cancer cells in a light-treated area. Additionally, photothermal efficacy of the micellar hydrogel is evaluated using a tumor-bearing mouse model; hollow gold nanospheres (HGNs) are used for comparison. Given the ability of the micellar hydrogel to provide spatial stability within a solid tumor, which prevents its leakage from the injection site, the therapeutic efficacy of this hydrogel, as a photothermal therapeutic agent for repeated treatments, exceeds that of nanosized HGNs. Results of this study demonstrate that this in situ -formed micellar hydrogel is a highly promising modality for repeated cancer treatments, providing a clinically viable, minimally invasive phototherapeutic option for therapeutic treatment. [ABSTRACT FROM AUTHOR]

Wecompared the crystallization rate of poly(3-hexylthiophene)(P3HT) in the film cast from the gel (called “gel-cast film”)with that in the film cast from the liquid solution (called “solution-castfilm”) to understand the effect of solution structure on thestructural development in the subsequently cast film of conjugatedpolymer. P3HT was found to form a homogeneous liquid solution withxylene at elevated temperature. When the freshly prepared semidilutesolution was allowed to age at room temperature, the solution transformedinto a gel in which a significant amount of nanowhiskers formed. Thenanowhiskers in the gel were effectively transferred to the correspondingcast film, while the film cast from the freshly prepared solutiononly contained a small amount of such a morphological entity. Thein situ small-angle X-ray scattering (SAXS) measurement and thermalanalysis revealed that both the cold and melt crystallization of P3HTin the gel-cast film were much slower than those in the solution-castcounterpart. The retardation of crystallization rate in the gel-castfilm was attributed to the abundance of the nanowhiskers. In thiscase, the crystallization of P3HT occurred predominantly within theindividual nanowhiskers and the mesh regions in the networks of thewhiskers, where their limited sizes in at least one dimension imposeda strong spatial constraint to the crystal growth and chain motionfor crystallization. [ABSTRACT FROM AUTHOR]

In comparison to the well-characterizedbottom-up synthesis ofAu and Ag nanomaterials, the synthesis of Cu nanocrystals with well-definedand controllable shapes is still in need of improvement. Among themany shapes, a cube covered by six {100} facets can be regarded asa standard model to study the surface properties of {100} facets.Herein, we have prepared monodisperse Cu nanoparticles having a slightlytruncated cubic shape with an average edge length of 75.7 nm and astandard deviation of 3.87% by using CuCl as the precursor, oleylamineas the reaction solvent, and trioctylphosphine and octadecylamineas shape control agents. The as-prepared Cu nanocubes tend to self-assembleon transmission electron microscopy grids or silicon substrates. Electronmicroscopy and small-angle X-ray scattering reveal that the Cu nanocubesprefer to self-assemble into 2D or 3D rhombohedral structures (RS).Large-area dense-packed films (1.5 cm × 2.5 cm) composed of monodisperseCu nanocubes were fabricated by immersing a Si substrate in a dispersionof dodecanethiol-capped Cu nanocubes in toluene and evaporating thetoluene at a controlled rate while holding the substrate at an angle.The electrical properties of the Cu films with various thickness andannealing temperatures were studied. [ABSTRACT FROM AUTHOR]

Poly(3-alkylthiophene)s (P3AT) areamong the most widely used conjugatedpolymers for applications in polymer solar cells and thin-film transistors.In this study, the influence of the casting solvent on the conformationalstructure and fluorescence properties of the isolated chains of aregioregular and a regiorandom poly(3-hexylthiophene) (denoted byrr-P3HT and ra-P3HT, respectively) has been systematically investigatedby single molecule spectroscopy. The isolated chains were dispersedin polystyrene matrix by casting from their ultradilute solutionswith tetrahydrofuran (THF) or toluene. ra-P3HT chains were found tocontain mostly high-energy emitting species with short conjugatinglength, while the low-energy emitting sites existed predominantlyin rr-P3HT chains irrespective of the casting solvent. The measurementof the modulation depth revealed that rr-P3HT chains cast from THFformed defect cylinder structure. The regioregular chains cast fromtoluene exhibited relatively regular folding to form rod structureas a result of the amplification of the segmental attraction in thepoorer solvent. The casting solvent had insignificant effect on theconformational structure of ra-P3HT, where the isolated chains predominantlyshowed defect coil conformation irrespective of the casting solvent. [ABSTRACT FROM AUTHOR]

Abstract: Use of an ionic liquid as a solvent to prepare silica aerogel via the sol–gel process has attracted considerable attention because a stable gel network can be formed during the aging process. One of the questions still remain unknown is the effect of the different molar ratios of ionic liquid to precursor on the resultant sol–gel framework structures of the synthesized silica gels; hence, such an effect will be explored in this article via small-angle X-ray scattering (SAXS). Herein, two silica gels have been synthesized using a short-chain ionic liquid, 1-butyl-3-methyl-imidazolium-tetrafluoroborate , as the solvent and tetraethyl orthosilicate (TEOS) as a precursor via an HCl-catalyzed sol–gel route. The molar ratio of to TEOS (denoted by n IL/n TEOS) was controlled to be stoichiometric and 3. The sample drying proceeded through solvent extraction method with a vacuum to avoid the risky supercritical drying step. Transmission electron microscopy (TEM) and SAXS analyses revealed that a silica aerogel could be prepared with stoichiometric n IL/n TEOS and exhibited an open mass-fractal silica framework formed by the aggregation of the individual spherical silica particles. To our knowledge, such a structural characteristic of spherical primary particle had not been confirmed in the other silica aerogels using IL as a solvent via SAXS so far. Inversely, a silica xerogel born from n IL/n TEOS =3 exhibited a collapsed sol–gel framework. The reasons leading to the structural differences derived from the different n IL/n TEOS will be explained with the sol pH values. Additionally, a two-level unified scattering function was also further adopted to fit the SAXS data to quantify the sizes of the mass-fractal clusters and their constituent silica particles. [Copyright &y& Elsevier]

Abstract: Although advantageous for siRNA packing and protection, chitosan (CS)-based complexes may lead to difficulties in siRNA release once they arrive at the site of action, due to their electrostatic interactions. To assist the intracellular release of siRNA and thus enhance its effectiveness in gene silencing, we incorporated a negatively charged poly(γ-glutamic acid) (γ-PGA) into CS/siRNA complexes. The inclusion of γ-PGA did not alter the complex-formation ability between CS and siRNA; additionally, their cellular uptake was significantly enhanced. The results obtained in our molecular dynamic simulations indicate that the binding between CS and siRNA remained stable in the cytosol environment. In contrast, the compact structure of the ternary CS/siRNA/γ-PGA complexes was unpacked; such a structural unpackage may facilitate the intracellular release of siRNA. In the gene silencing study, we found that the inclusion of γ-PGA into complexes could significantly expedite the onset of gene knockdown, enhance their inhibition efficiency and prolong the duration of gene silencing. These findings may be attributed to the fact that there were significantly more CS/siRNA/γ-PGA complexes internalized into the cells in company with their more rapid intracellular unpackage and release of siRNA when compared with their binary counterparts in the absence of γ-PGA. The aforementioned results suggest that CS/siRNA/γ-PGA complexes can be an efficient vector for siRNA transfection. [ABSTRACT FROM AUTHOR]

Abstract: A pH-sensitive nanoparticle (NP) system composed of chitosan and poly(γ-glutamic acid) was prepared for the oral delivery of insulin. The biodistribution study in a rat model showed that some of the orally administered NPs were retained in the stomach for a long duration, which might lead to the disintegration of NPs and degradation of insulin. To overcome these problems, we freeze-dried NPs and filled them in an enteric-coated capsule. The small angle X-ray scattering (SAXS) profiles indicated that the freeze-drying process did not significantly disrupt the internal structure of NPs; additionally, their pH-sensitivity was preserved and the insulin release was pH-dependent. The results obtained in the native PAGE analysis indicated that the released insulin molecules were neither fragmented nor aggregated. Upon oral administration, the enteric-coated capsule remained intact in the acidic environment of the stomach, but dissolved rapidly in the proximal segment of the small intestine. Consequently, all the NPs loaded in the capsule were brought into the small intestine, thus enhancing the intestinal absorption of insulin and providing a prolonged reduction in blood glucose levels. The relative bioavailability of insulin was found to be approximately 20%. These results suggest that the formulation developed in the study might be employed as a potential approach for the oral delivery of insulin. [Copyright &y& Elsevier]

Abstract: Using a simple sol–gel method, a novel magnetic photocatalyst was produced by immobilization of TiO2 nano-crystal on Fe-filled carbon nanocapsules (Fe-CNC). High resolution TEM images indicated that the immobilization of TiO2 on Fe-CNC was driven primarily by heterogeneous coagulation, whereas surface nucleation and growth was the dominant mechanism for immobilizing TiO2 on acid-functionalized hollow CNC. The TiO2 immobilized on Fe-CNC exhibited the anatase phase as revealed by the X-ray diffraction (XRD) patterns. In comparison with free TiO2 and TiO2-coated CNC, TiO2-coated Fe-CNC displayed good performance in the removal of NO gas under UV exposure. Due to the advantages of easy recycling and good photocatalytic efficiency, the novel magnetic photocatalyst developed here has potential use in photocatalytic applications for pollution prevention. [Copyright &y& Elsevier]

Block copolymers show interesting phase behavior if at least one of the constituting blocks is crystallizable. The morphology development becomes highly complex when such a block copolymer is crystallized above the glass transition temperature of the amorphous block due to competition between microphase separation and crystallization during the structure evolution process. In this review, we focus on the morphology development in such crystalline‐amorphous (C‐A) diblock copolymers where the amorphous block remains rubbery during the crystallization process. Crystallization behavior in bulk as well as in thin films is considered. The issue of crystal orientation and chain folding upon crystallization in these diblock copolymers has been discussed. Moreover, the nucleation mechanism in these C‐A diblock copolymers and its effect on their crystallization kinetics is also described. Some of the emerging areas of research such as crystallization behavior in blend of C‐A diblock copolymers has been briefly discussed and finally the future challenges, which holds promise for our further in‐depth understanding of crystallization in block copolymers, has been identified. [ABSTRACT FROM PUBLISHER]

Abstract: In this work, TiO2 nanoparticles were immobilized on the carbon nanocapsules (CNC) treated by H2SO4/KMnO4 using a sol-gel process. The TEM images of the TiO2-coated CNC suggested that introducing crystallographic defects by acid functional groups tended to facilitate TiO2 immobilization onto the nanocapsules. The TiO2-coated CNC exhibited effective quenching on the emission of a light-emitting conjugated polymer, poly(2-phenyl-3-phenyl-4-(3′,7′-dimethyloctyloxy)-1,4-phenylene vinylene) (DPO-PPV). Consequently, the composites of the TiO2-coated CNC and conjugated semiconducting polymers have potentials for photovoltaic applications. [Copyright &y& Elsevier]

The innate cartilage extracellular matrix is avascular and plays a vital role in innate chondrocytes. Recapping the crucial components of the extracellular matrix in engineered organs via polymeric gels and bioinspired approaches is promising for improving the regenerative aptitude of encapsulated cartilage/chondrocytes. Conventional gel formation techniques for polymeric materials rely on employing oxidative crosslinking, which is constrained in this avascular environment. Further, poor mechanical properties limit the practical applications of polymeric gels and reduce their therapeutic efficacy. Herein, the purpose of this study was to develop a bioadhesive gel possessing dual crosslinking for engineering cartilage. Tyramine (TYR) was first chemically conjugated to the alginate (ALG) backbone to form an ALG-TYR precursor, followed by the addition of calcium peroxide (CaO 2); calcium ions of CaO 2 physically crosslink with ALG, and oxygen atoms of CaO 2 chemically crosslink TYR with tyrosinase, thus enabling dual/enhanced crosslinking and possessing injectability. The ALG-TYR/tyrosinase/CaO 2 gel system was chemically, mechanically, cellularly, and microscopically characterized. The gel system developed herein was biocompatible and showed augmented mechanical strength. The results showed, for the first time, that CaO 2 supplementation preserved cell viability and enhanced the crosslinking ability, bioadhesion, mechanical strength, chondrogenesis, and stability for cartilage regeneration. [ABSTRACT FROM AUTHOR]

The effect of supercritical CO 2 on the morphological structure of crystalline/amorphous PEO/PVAc blends was investigated by means of SAXS with the measurement of absolute scattering intensity. The morphological structure of PEO/PVAc exhibited a considerable change upon CO 2 treatment as demonstrated by the drastic increase of scattering intensity, or the enhancement of electron density contrast between the crystalline and amorphous layers in the lamellar stacks, resulting from the swelling of amorphous PEO via the incorporation of CO 2 into the interlamellar (IL) regions and/or the expulsion of PVAc from the IL regions. Upon CO 2 treatment, the crystal and amorphous layer thickness ( l c and l a , respectively) were both increased. Compared with the increase of l a , the increase of l c was relatively significant and was attributed to the occurrence of melting and recrystallization during CO 2 treatment leading to thicker PEO crystals via a depression of equilibrium melting temperature and/or an increase of crystal fold surface free energy. The measured electron density contrast revealed that the distance of segregation in PEO/PVAc blends involved the extralamellar segregation before CO 2 treatments and the swelling of interlamellar region dominated the drastic increase of scattering intensity after CO 2 treatments. The finding of extralamellar morphology was consistent with the magnitude of volume fraction of lamellar stacks in the blends. The lamellar size distribution appeared to be broader and the lamellar stacks more disorganized for the blends after CO 2 treatments according to SAXS one-dimensional correlation function profiles. [ABSTRACT FROM AUTHOR]

Patients with irregular, huge burn wounds require time-consuming healing. The skin has an epithelial barrier mechanism. Hence, the penetration and retention of therapeutics across the skin to deep lesion is generally quite difficult and these usually constrain the delivery/therapeutic efficacies for wound healing. Effective burn wound healing also necessitates proper circulation. Conventional polymeric dressing usually exhibits weak mechanical behaviors, obstructing their load-bearing applications. Cold atmospheric plasma (CAP) was used as an efficient, environmentally friendly, and biocompatible process to crosslink methylcellulose (MC) designed for topical administration such as therapeutic substances of platelets (SP) and polyethyleneimine-polypyrrole nanoparticle (PEI-PPy NP)-laden MC hydrogel carriers, and wound dressings. The roles of framework parameters for CAP-treated SP-PEI-PPy NP-MC polymeric complex system; chemical, physical, and photothermal effects; morphological, spectroscopical, mechanical, rheological, and surface properties; in vitro drug release; and hydrophobicity are discussed. Furthermore, CAP-treated SP-PEI-PPy NP-MC polymeric complex possessed augmented mechanical properties, biocompatibility, sustainable drug release, drug-retention effects, and near-infrared (NIR)-induced hyperthermia effects that drove heat-shock protein (HSP) expression with drug permeation to deep lesions. This work sheds light on the CAP crosslinking polymeric technology and the efficacy of combining sustained drug release with photothermal therapy in burn wound bioengineering carrier designs. [ABSTRACT FROM AUTHOR]

Quasi-solid thermoelectrochemical cells (TECs) are promising candidates for wearable energy harvesting devices as they enable the continuous conversion of low-grade heat into electricity. However, the TEC performance remains limited by inadequate ionic conductivity. Herein, a triple-network hydrogel consisting of polyacrylamide/poly(vinyl alcohol)/cellulose nanofiber (PAAM/PVA/CNF) is synthesized via a freeze-thaw method, and soaked in the thermogalvanic redox couple Fe(CN) 6 3−/4– as the electrolyte. By optimizing the polymer composition and soaking time, a superior ionic conductivity of 168 mS cm−1 is achieved while maintaining a thermopower of ∼1.69 mV K−1. The high ionic conductivity is provided by the fractal microstructure of the hydrogel, as revealed by small-angle X-ray scattering (SAXS). Moreover, the as-fabricated thermoelectric generator array exhibits an exceptional power output of 28.7 μW at a temperature difference of 11.9 K. This work provides insights on the development of wearable thermoelectric materials for practical and reliable energy harvesting applications. [Display omitted] • Novel quasi-solid thermoelectrochemical cells made of triple-network hydrogel. • To reveal the nanostructure behavior of thermoelectrochemical cells by SAXS and WAXS. • High ionic conductivity corelated to nanostructure appearance. • Excellent wearable electronics performance with 9-series connected TEG. [ABSTRACT FROM AUTHOR]

• Structure of key polysaccharides in solution to sub-Ångstrom accuracy. • Resolve the helical conformation of polysaccharides. • Directly reveal the flexibility of different glycosidic linkages. • Structural characterization of polymers which exhibit strong inter-particle effects that dominate other methods. Polysaccharides are semi-flexible polymers composed of sugar residues with a myriad of important functions including structural support and energy storage. The local conformation of such chains is a crucial factor governing their interactions. Traditionally this conformation has only been directly accessible in the solid-state, using crystallographic techniques such as fibre diffraction. Herein it is demonstrated that improvements in the quality of synchrotron-based X-ray scattering data means that conformation-dependent features, the positions of which are related to the linear repeating distance between single saccharide monomers, can now be measured in solution. This technique is expected to be universally applicable for polysaccharides. [ABSTRACT FROM AUTHOR]

A series of poly(l-lactide)/poly(d-lactide) blended chips (LDC), as-spun LD fibers (LDA) and hot-drawn LD fibers (LDH) were prepared for investigating the homocrystallization and stereocomplex crystallization behaviors of LDA and LDH fibers during heating. Modulated differential scanning calorimetry (MDSC), hot stage polarized microscopy (HSPM), and real-time wide-angle X-ray diffraction (WAXD) were used for studying the crystallization and melting behaviors, fiber morphology, and crystalline structure evolution of the LDA and LDH fibers' homocrystals and stereocomplex crystals during heating. The molecular chain orientations of the LDA and LDH fibers were obtained through spinning and improved through the hot drawing processes. When the molecular chain was oriented on the fiber axis, the homocrystals and stereocomplex crystals of the fibers began to form in turn as the heating temperature exceeded the glass transition temperature of the fiber. The side-by-side packing of the molecular chains was promoted by mixing the molecular chains with the extrusion screw during the spinning process, facilitating stereocomplex crystallization. When the LDA fiber was heated above the glass transition temperature of the fiber, movement of the fiber molecular chain—including molecular chain orientation and relaxation, as well as crystallization, melting, and recrystallization of homocrystals and stereocomplex crystals—were investigated through HSPM. MDSC and real-time WAXD were used to observe the molecular chains of the melted poly(l-lactide) and poly(d-lactide) homocrystals of the fibers rearranging and transiting to form stereocomplex crystals during heating. [ABSTRACT FROM AUTHOR]

Abstract A heterocyclic polyamide 6 (i.e. caprolactam (CPL; 90 mol%)/sebacic acid (SBA; 5 mol%)/1,3-cyclohexanebis (methylamine)(CHM; 5 mol%) copolyamide) with superior transparency, haze, hygroscopicity and crystallinity to an ordinary polyamide 6 (PA 6) based on CPL (100 mol%) have prepared by the design of appropriate prescriptions. The transparency, haze, hygroscopicity, and crystallinity of lab-made heterocyclic PA 6 are 86.5%, 13.2%, 1.36% (24hr)/1.89% (48hr), and 11.5%, respectively, while those of PA 6 are 26.0%, 94.2%, 1.80% (24hr)/2.45% (48hr), and 24.0%, respectively. Experimental results demonstrate that physical properties of lab-made heterocyclic PA 6 deeply depend on its heterocyclic structure and introduction of SBA and CHM into PA 6 can effectively improves optical, hygroscopic, thermal decomposition, and crystalline characteristics of PA 6, revealing that it is a highly potential polymeric material for optical films, electrical encapsulation, and food packages. Highlights • A novel polyamide was prepared by the proper recipe. • The polyamide exhibits good physical properties. • The polyamide with low moisture absorption is transparent. • The polyamide possesses superior optical and hygroscopic performances to PA 6. • The polyamide is a potential polymer for optical films and package applications. [ABSTRACT FROM AUTHOR]

Abstract: Poly(3‐hexylthiophene) (P3HT) nanowires have drawn great attention recently because of their unique properties that can be applied to optoelectronic devices such as conjugated polymer solar cells and organic field‐effect transistors. There is still an urgent need, however, to study the fabrication and characterization of P3HT nanowires with controllable morphologies and molecular orientations. In this work, feasible routes are presented to fabricate P3HT nanowires using the solution wetting template method and the solvent‐annealing‐induced nanowetting in template (SAINT) method. The morphologies and chemical compositions of the P3HT nanowires prepared using these two methods are confirmed by scanning electron microscopy, transmission electron microscopy (TEM), and Raman spectroscopy. From the ultraviolet‐visible spectroscopy and wide‐angle X‐ray scattering results, it is concluded that the degrees of the crystallinity and the orientation preferences of interchain stackings along the pore axis for the P3HT nanowires prepared by the SAINT method are higher than those prepared by the solution wetting template method. [ABSTRACT FROM AUTHOR]

Films of ethylene vinyl alcohol copolymer (EVOH) and EVOH containing poly(oxypropylene)diamine intercalated montmorrilonite were prepared by solution casting. The nanostructures and viscosity were characterized by small angle x-ray scattering (SAXS), transmission electron microscopy (TEM) and rheological testing. The nonisothermal crystallization kinetics of the samples were investigated by the Ozawa's and Mo's methods and the crystallization activation energy by Kissinger's model. The SAXS and TEM analysis demonstrated that the nanoplatelets, with an intercalated structure, were dispersed in the EVOH matrix. The rheological tests showed that the incorporation of the modified clay could increase the viscosity of the composite system. The Mo's method more successfully described the nonisothermal ctystallization behavior of neat EVOH and its nanocomposites as compared with the Ozawa's method. Adding the nanoclays had a heterogeneous nucleation effect to accelerate the crystallization of EVOH despite hindering the macromolecular chains movement. [ABSTRACT FROM AUTHOR]

Biomaterial-based devices have demonstrated versatility in various applications and have drawn recent considerable attention. In this study, we present non-volatile resistive switching memory devices based on a natural-derived DNA biomaterial. The structure consists of a DNA-based biomaterial layer sandwiched between two electrodes, where the DNA-based biomaterial is solution-processed without sequence control or external doping of nanoparticles. The fabricated device was tested at room temperature without encapsulation and exhibited a reliable resistive switching behavior and multi-level operation with low switching voltages, 10 4 s retention time, and more than 200 cycles in memory endurance testing. Our demonstration shows that reliable memory devices can be realized using only one layer of natural DNA biomaterial, without the need for composite layers. Our characterization also provides underlying physics that may be exploited for the design and fabrication of natural DNA-based optoelectronics. [ABSTRACT FROM AUTHOR]

The formulation of a drug using high-energy emulsification commonly causes drug deterioration. Exploiting the well-known Diet Coke–Mentos reaction (DCMR), a U-shaped tube reactor that can generate an eruption of bubbly flow that can serve as a low-energy emulsification platform, is proposed. The liquid in the U-tube reactor is a supersaturated solution of aqueous CO 2 , which mimics Diet Coke. When glass beads with rough surfaces, mimicking Mentos, are dropped into the carbonated water, an eruptive bubbly flow is spontaneously created, mediating effective emulsification at a compound water–oil interface. Experimental results demonstrate that DCMR-mediated bubbly flow may provide a versatile platform for the production of "oil-in-water" or "water-in-oil" droplets and Pickering emulsion composite particles as drug carriers. The DCMR-derived bubbly flow is generated without significant temperature elevation, so the activity of the drug to be emulsified is unaffected. In vivo results reveal the feasibility of using this low-energy emulsification platform to formulate an emulsion system that contains catalase, a temperature-sensitive oxidoreductase, to mitigate an experimentally formed paw inflammation in mice. The as-proposed emulsification platform is attractive for formulating numerous drug delivery systems on a small-scale in a customized manner to meet the needs of each individual for personalized medicine. [ABSTRACT FROM AUTHOR]

A long-chain branched copolyester (i.e. p -hydroxybenzoic acid (HBA)/2-hydroxy-6-naphthoic acid (HNA)/1,1,1-tris(4-hydroxyphenyl)ethane (THPE) copolyester) and its extrusion film with superior physical properties to commercial Ticona A950 and Vecstar CTZ have been manufactured by the design of appropriate prescriptions, T-Die extrusion, and thermal treatment of crystal transformation. In order to investigate the fabricating feasibility for flexible copper clad laminate (FCCL) of fourth/fifth generation long-term evolution (4G/5G LTE), we have also agglutinated lab-made copolyester extrusion film with the copper foil by hot compression. Experimental results manifest that lab-made copolyester extrusion film is a highly potential FCCL substrate of 4G/5G LTE because its thickness, dielectric constant (D k ), dielectric loss (D f ), hygroscopicity, yellowness index (YI), antistatic capability, flammability, melting temperature (T m ), coefficient of thermal expansion (CTE), and peel strength to copper foil are 50 μm, 2.90, 0.00140, 0.04%, 2.7, 6.5 × 10 9 Ω/□, UL-94 V0, 305 °C, 24.8 ppm/°C, and 29.9 lb/in, respectively. [ABSTRACT FROM AUTHOR]

Sodium dodecyl sulfate (SDS) is generally regarded as a potent permeability enhancer in oral formulations; however, one concern related to the use of any permeation enhancer is its possible absorption of unwanted toxins during the period of epithelial permeability enhancement. In this work, the safety and efficacy of an SDS-containing bubble carrier system that is developed from an orally administered enteric-coated capsule are evaluated. The bubble carriers comprise diethylene triamine pentaacetic acid (DTPA) dianhydride, sodium bicarbonate (SBC), SDS, and insulin. Upon exposure to the intestinal fluid, DTPA dianhydride hydrolyzes to yield acids, and SBC rapidly reacts with these acids to generate CO 2 , producing bubble carriers, each containing a self-assembling water film. The hydrophilic insulin is entrapped in the self-assembled water film, which is stabilized by SDS. The SDS in the bubble carrier system can act as a dissolution enhancer in the dispersion of insulin molecules, as a surfactant that stabilizes the bubble carriers, as a protease inhibitor that protects the protein drug, and as a permeation enhancer that augments its oral bioavailability. Hence, a significant increase in the plasma insulin level and an excellent blood glucose-lowering response in diabetic rats are effectively achieved. Moreover, the enhancement of epithelial permeation by this SDS-containing formulation does not promote the absorption of intestinal endotoxins. The above facts indicate that the bubble carrier system that is stabilized by SDS can be used as a safe and potent carrier in the oral delivery of therapeutic proteins. [ABSTRACT FROM AUTHOR]

Molecular conformation and the assembly structure determine the spatial arrangements of the constituent units and the functions of a molecule. Although, fullerene hexa-adducts (FHAs) have been known as functional materials with great versatility, their conformational preferences and phase stability remain a complicate issue. By choosing bithiophene (T2) and dodecyl bithiophene (C12T2) as the peripheral units of FHA, and using microscopic, scattering and diffraction characterizations, our study reveals how the intramolecular interaction and environmental stimulus affects the conformational preferences and phase stability of FHAs. [ABSTRACT FROM AUTHOR]

This study investigates the interfacial strengths between polypropylene (PP)/carbon fiber (CF) composites through experimental observation as well as using molecular dynamics (MD) simulation to determine optimal chemical functionalization groups for four PP/CF composites. First, the structures of PP/CF, PP- graft -maleic anhydride (PP-MAH)/CF, PP-MAH/CF-NH 2 (2%) and PP-MAH/CF-NH 2 (5%) were constructed to obtain stable interface structures by the simulated-annealing procedure, and these structures were further used to evaluate the interface bonding strength. The study found that the degrees of crystallinity of PP and PP-MAH at the interfaces are significantly improved when compared to those of the pristine structure. The results show, through the interaction energy per unit area and the tensile simulation mechanical strength, that the strengths of the modified PP/functionalized-CF are higher. Finally, the MD simulation results of the modified PP and functionalized-CF composites are demonstrated to provide an economical and quick approach to examine the mechanical properties of a polymer composite system before conducting an experiment. Such MD results can be utilized to guide both the design of polymer/carbon fiber composites and to select proper functionalized groups. [ABSTRACT FROM AUTHOR]

Successful oral delivery of therapeutic proteins such as insulin can greatly improve the quality of life of patients. This study develops a bubble carrier system by loading diethylene triamine pentaacetic acid (DTPA) dianhydride, a foaming agent (sodium bicarbonate; SBC), a surfactant (sodium dodecyl sulfate; SDS), and a protein drug (insulin) in an enteric-coated gelatin capsule. Following oral administration to diabetic rats, the intestinal fluid that has passed through the gelatin capsule saturates the mixture; concomitantly, DTPA dianhydride produces an acidic environment, while SBC decomposes to form CO 2 bubbles at acidic pH. The gas bubbles grow among the surfactant molecules (SDS) owing to the expansion of the generated CO 2 . The walls of the CO 2 bubbles consist of a self-assembled film of water that is in nanoscale and may serve as a colloidal carrier to transport insulin and DTPA. The grown gas bubbles continue to expand until they bump into the wall and burst, releasing their transported insulin, DTPA, and SDS into the mucosal layer. The released DTPA and SDS function as protease inhibitors to protect the insulin molecules as well as absorption enhancers to augment their epithelial permeability and eventual absorption into systemic circulation, exerting their hypoglycemic effects. [ABSTRACT FROM AUTHOR]

The structures of C- and N-terminallymonoPEGylated human parathyroidhormone fragment hPTH(1–34) as well as their unmodified counterparts,poly(ethylene glycol) (PEG) and hPTH(1–34), have been studiedby small-angle neutron scattering (SANS). The scattering results showthat free hPTH(1–34) in 100 mM phosphate buffer (pH 7.4) aggregatesinto clusters. After conjugation with PEG, the PEG–peptideconjugates self-assemble into a supramolecular core–shell structurewith a cylindrical shape. The PEG chains form a shell around the hPTH(1–34)core to shield hPTH(1–34) from the solvent. The detailed structuralinformation on the self-assembled structures is extracted from SANSusing a model of the cylindrical core with a shell of Gaussian chainsattached to the core surface. On the basis of the data, because ofthe charge–dipole interactions between the conjugated PEG chainand the peptide, the conjugated PEG chain forms a more collapsed conformationcompared to free PEG. Moreover, the size of the self-assembled structuresformed by the C-terminally monoPEGylated hPTH(1–34) is about3 times larger than that of the N-terminally monoPEGylated hPTH(1–34).The different aggregation numbers of the self-assembled structures,triggered by different PEGylation sites, are reported. These sizediscrepancies because of different PEGylation sites could potentiallyaffect the pharmacokinetics of the hPTH(1–34) drug. [ABSTRACT FROM AUTHOR]

Based on our recent understanding and development of functionalized molecular nanoparticles (MNPs) as building blocks for constructing various giant molecules, we report our efforts on design and synthesis of an asymmetric giant amphiphile, diBPOSS-C60, composed of one [60]fullerene (C60) covalently linked with two isobutyl-functionalized polyhedral oligomeric silsesquioxane (BPOSS) MNPs. Its crystal structure and molecular packing were investigated. The compositional asymmetry between C60 and BPOSS led to a "sandwich-layered" molecular packing scheme, where a single layer of C60 is sandwiched between double BPOSS layers: a so-called "one-and-half-layered" structure. Within these layers, the molecules further organized into crystalline arrays. Interestingly, this compound can be viewed as size amplification of a class of atomically thin, two-dimensional layered transition metal dichalcogenides with the "one-and-half-layered" structure. [ABSTRACT FROM AUTHOR]

Anhand theoretischer Modelle lässt sich vorhersagen, dass eine Vielzahl von durch Selbstorganisation gebildeten Strukturen dicht gepackter kugelförmiger Partikel entstehen kann, wenn diese in zylindrischen Räumen eingeschlossen werden. In der vorliegenden Arbeit demonstrieren wir zum ersten Mal, dass polymerbeschichtete Nanopartikel, die in den selbstorganisierten zylindrischen Domänen eines Blockcopolymers eingeschlossen sind, sich in einer helixförmig gepackten Morphologie anordnen. Es gelang uns, einzelne mit helixförmig angeordneten Nanopartikeln gefüllte Fasern zu isolieren. Dieses Ergebnis eröffnet einzigartige Möglichkeiten sowohl für die Grundlagenforschung als auch für die anwendungsorientierte Forschung. Lockere Schrauben im Kunststoffmantel: In selbstorganisierten zylindrischen Domänen von Polystyrol ‐ block ‐ poly(4 ‐ vinylpyridin) (PS ‐ b ‐ P4VP) treten eingeschlossene Silber ‐ Nanopartikel in einer bemerkenswerten Packung mit helixförmiger Morphologie auf. Diese Beobachtung könnte für die Grundlagen ‐ und anwendungsorientierte Forschung von Interesse sein. [ABSTRACT FROM AUTHOR]