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1.
Developing sponge materials integrating excellent flame retardancy, multitasking separation performance, and efficient emulsion‐breaking ability is significant but challenging for the remediation of oil spills causing fires and environmental damages. Herein, a superhydrophobic oil–water separation sponge material, containing a melamine‐formaldehyde (MF) sponge substrate, magnetic polydopamine (PDA) coating, and branched polydimethylsiloxane (PDMS) brush, through dopamine‐mediated surface initiated atom transfer radical polymerization (SI‐ATRP) is fabricated. The synergistic flame resistance of the MF substrate and PDMS brush significantly improves its adaptability in fire. More importantly, the decorated PDMS brushes can effectively overcome the size mismatch between sponge macropores and tiny emulsified droplets, while remaining the intrinsic macroporous characteristic. When treating W/O emulsions, the PDMS brushes stretch up to act as “interface‐breaking blades” to accelerate the coalescence of emulsified water droplets. Meanwhile, such PDMS brushes can serve as “oil‐trapping tentacles” to efficiently capture oil droplets when treating O/W emulsions. Such material design synergistically contributes to satisfactory separation efficiency (98.7%) and ultrahigh permeation flux (up to 1.35 × 105 L m?2 h?1), even for treating high viscosity emulsions. Besides, the reported sponge also inherits robust durability, superior recyclability, and convenient magnetic collection. These features make the sponge promising for multitasking and highly efficient oil–water separation.  相似文献   

2.
The generation of near‐infrared (NIR)‐sensitive microcapsules is presented and it is demonstrated that the release properties of these microcapsules can be tailored by controlling their morphology. A biocompatible polymer, poly(DL‐lactic‐co‐glycolic)acid (PLGA) is used to form hollow microcapsules from monodisperse water‐in‐oil‐in‐water (W/O/W) double emulsions. Both the composition of PLGA and the oil phase of W/O/W double emulsions significantly affect the morphology of the subsequently formed microcapsules. PLGA microcapsules with vastly different morphologies, from spherical to “snowman‐like” capsules, are obtained due to changes in the solvent quality of the oil phase during solvent removal. The adhesiveness of the PLGA‐laden interface plays a critical role in the formation of snowman‐like microcapsules. NIR‐sensitive PLGA microcapsules are designed to have responsive properties by incorporating Au nanorods into the microcapsule shell, which enables the triggered release of encapsulated materials. The effect of capsule morphology on the NIR responsiveness and release properties of PLGA microcapsules is demonstrated.  相似文献   

3.
This article describes the synthesis of a DNA–polymer, being the nucleotide sequence an aptamer selected in vitro to target specifically the immunoglobulin E (IgE) protein, an allergy biomarker. Subsequent to coupling to poly(2‐alkyl‐2‐oxazoline) with N‐Boc protected amino acid side chains, the resulting amphiphilic DNA–polymer hybrid composed of the water‐soluble DNA fragment grafted to the hydrophobic polymer segment can be regarded as a high molecular weight analogue of a surfactant. It is demonstrated that the copolymer–aptamer stabilizes efficiently submicrometer size oil‐in‐water and water‐in‐oil emulsions, by dynamic light scattering, microscopy, and reflectometry. Particularly interesting is that the aptamer remains functional after coupling to a polymer backbone, stabilization of the emulsion droplets, and locking of the structure subsequent to cross‐linking polymerization. The resulting nanocapsules still target specifically the IgE protein. The biological‐stimulus responsiveness of the structures is of high potential for future developments of carriers for sustained and targeted delivery.  相似文献   

4.
The conductivity of charge-ordered layered crystals in electric and quantizing magnetic fields orthogonal to the layers is calculated. Charge ordering is considered as an alternation of layers with different charge-carrier densities. When scattering by acoustic phonons, conductivity is calculated in the approximation of profound quantization, so that the intersubband transitions can be assumed to be suppressed. It is shown that, in the transition of the layered crystal from the disordered to almost completely ordered state, the conductivity oscillations exhibit double periodicity. In this case, the high “carrier” frequency is controlled by the effective attractive electron-electron interaction responsible for charge ordering, whereas the low “modulation” frequency is defined by the width of the narrow miniband orthogonal to the layers. It is also shown that, in the transition from a disordered to an almost completely ordered state, the longitudinal conductivity of layered crystals decreases by two or three orders of magnitude. At the same time, the relative contribution of oscillations sharply increases, with satisfactory agreement to the experimental data.  相似文献   

5.
目的:对急进高原个体胆汁返流与急性胃肠粘膜损伤的关系进行探讨。方法:对20例由平原急进高原个体进入高原前、进入高原第3天和第7天进行胃镜检查,对其胆汁返流、胃黏膜损伤及其消化系统的症状发生情况进行调查。结果:20例急进高原个体进入高原后胆汁返流及胃粘膜损伤与进入高原前比较,除进入高原第7天胆汁返流无显著差异外,其余均有显著差异(分别为P〈0.01和P〈0.05),其中胆汁返流进入高原前、进入高原第3天及第7天分别为0例(0%)1、0例(50%)、5例(25%);粘膜损伤分别为2例(10%)1、7例(85%)、10例(50%);其中13例有不同程度的消化系统症状(占65%)。结论:高原急性缺氧可引发急进高原个体胆汁返流的高发生率,并因此而导致急性胃肠粘膜损伤。  相似文献   

6.
Three‐dimensional printing of viscoelastic inks to create porous, elastomeric architectures with mechanical properties governed by the ordered arrangement of their sub‐millimeter struts is reported. Two layouts are patterned, one resembling a “simple cubic” (SC)‐like structure and another akin to a “face‐centered tetragonal” (FCT) configuration. These structures exhibit markedly distinct load response with directionally dependent behavior, including negative stiffness. More broadly, these findings suggest the ability to independently tailor mechanical response in cellular solids via micro‐architected design. Such ordered materials may one day replace random foams in mechanical energy absorption applications.  相似文献   

7.
Herein, the exploration of natural plant‐based “spores” for the encapsulation of macromolecules as a drug delivery platform is reported. Benefits of encapsulation with natural “spores” include highly uniform size distribution and materials encapsulation by relatively economical and simple versatile methods. The natural spores possess unique micromeritic properties and an inner cavity for significant macromolecule loading with retention of therapeutic spore constituents. In addition, these natural spores can be used as advanced materials to encapsulate a wide variety of pharmaceutical drugs, chemicals, cosmetics, and food supplements. Here, for the first time a strategy to utilize natural spores as advanced materials is developed to encapsulate macromolecules by three different microencapsulation techniques including passive, compression, and vacuum loading. The natural spore formulations developed by these techniques are extensively characterized with respect to size uniformity, shape, encapsulation efficiency, and localization of macromolecules in the spores. In vitro release profiles of developed spore formulations in simulated gastric and intestinal fluids have also been studied, and alginate coatings to tune the release profile using vacuum‐loaded spores have been explored. These results provide the basis for further exploration into the encapsulation of a wide range of therapeutic molecules in natural plant spores.  相似文献   

8.
Partial order in crystals is a frequently observed phenomenon in minerals and synthetic materials. The partially ordered structures are characterized by low-dimensional order of the real structure. In the case of 1D structures, the ordered units can be described as rods; 2D structures contain ordered layers. The disorder of the real structures is indicated by prominent diffuse scattering in the diffraction patterns of single crystals. No simple method for the quantitative analysis of the diffuse scattering exists, therefore the determination of essential characteristics of the structures is complicated. However, the determination can be facilitated using a combination of different methods, including electron microscopy, computation and X-ray diffraction.  相似文献   

9.
The low survival rate in harsh stomach conditions and short retention in intestine of probiotics greatly limit their health benefits. To solve this problem, thiolated oxidized konjac glucomannan (sOKGM) microspheres is designed with pH responsive and mucoadhesive properties. First, an increased survival rate of probiotics by sOKGM microspheres encapsulation in simulated gastric fluid (SGF) is discovered in contrast to the zero‐survival rate of naked probiotics. sOKGM/probiotics even show a higher survival rate in SGF compared with commercial Bb12 formulation. Further, an enhanced mucoadhesion of probiotics to intestinal mucus by mediated interactions with sOKGM is confirmed by isotherm titration calorimetry, rheology, and tensile measurements. The in vivo intestinal transition experiment indicates a prolonged retention of probiotics at intestine by sOKGM encapsulation. Moreover, in vivo evaluation of enhanced colonization and proliferation by sOKGM/probiotics is demonstrated by the fecal and intestinal bacteria copy number via quantitative polymerase chain reaction (qPCR) detection. Further investigation of the alleviation of constipation by sOKGM containing Bifidobacterium animalis subsp. lactis A6 suggests that sOKGM increases the abundance of Bifidobacterium, balanced intestinal flora, and alleviated constipation in mice compared with other formulations. sOKGM with both enhanced gastric acid resistance and adhesion colonization at intestine can effectively improve the function of probiotics.  相似文献   

10.
Inspired by the self‐assembled bilayer structures of natural amphiphilic phospholipids, a new class of highly luminescent “click”‐phospholes with exocyclic alkynyl group at the phosphorus center is reported. These molecules can be easily functionalized with a self‐assembly group to generate neutral “phosphole‐lipids”. This novel approach retains the versatile reactivity of the phosphorus center, allowing further engineering of the photophysical and self‐assembly properties of the materials at a molecular level. The results of this study highlight the importance of being able to balance weak intermolecular interactions for controlling the self‐assembly properties of soft materials. Only molecules with the appropriate set of intermolecular arrangement/interactions show both organogel and liquid crystal mesophases with well‐ordered microstructures. Moreover, an efficient energy transfer of the luminescent materials is demonstrated and applied in the detection of organic solvent vapors.  相似文献   

11.
The atomic-scale structure of cuprous selenide room temperature phase (α-Cu2Se), which plays an important role in understanding the mechanism of its high thermoelectric performance, is still not fully determined. Here, direct observation with atomic-scale resolution is realized to reveal the fine structure of α-Cu2Se via spherical-aberration-corrected scanning transmission electron microscopy. It is observed to be an interesting self-independent binary-sublattice construction for Cu and Se in α-Cu2Se, respectively, which shows a variety of ordered copper fluctuation structures are embedded in a rigid pseudo-cubic Se sublattice. Ordering of Cu uses a variety of configurations with little energy difference, forming considerable amounts of “boundaries,” which may lead to ultrastrong phonon scattering. Furthermore, density functional theory calculations indicate that the electronic structures are mainly determined by the rigid Se face-centered cubic sublattice and not sensitive to the various copper fluctuations, which may guarantee the electron transfers with large carrier mobility. The self-independent binary-sublattice construction is speculated to enhance phonon scattering while still maintaining good electrical transport property. This study provides new critical information for further understanding the possible correlation between the specific structure and thermoelectric performance of α-Cu2Se, as well as designing new thermoelectric materials.  相似文献   

12.
Emulsified oil leakage onto the bulk water surface causes severe issues on global ecology and health. Developing efficient, rapid, and universal separation methods of emulsions has been a significant topic in scientific studies. However, a contactless and additive-free strategy to achieve continuous floating emulsion separation and oil collection remains to be discovered. Herein, a universal contactless demulsification, transportation, and collection method to dispose floating emulsions by ionic wind, which contains active charged particles generated by corona discharge is reported. The splash-like demulsification process of floating emulsions is attributed to the rupture of water film enveloped on oil droplet surface, simultaneously and respectively. The evidence of this process recorded by a high-speed camera with 20 000 fps has a referential significance for other works. This study may clean up universal floating emulsions discharged on water in real situations such as oil stations, chemical plants, and restaurants, and furthermore increase the potential of remote control in liquid dynamics by corona discharge.  相似文献   

13.
The finite element method is combined with the mode-matching method and the multi-mode network method to analyze the scattering and radiation characteristics of a class of planar dielectric waveguide discontinuities. Unlike the conventional method to treat the radiation as a “source-field” problem, in the present approach, the dispersion characteristics of dielectric guided-wave structures are calculated first, and then the radiation problem is transferred to the propagation problem of a series of surface-waves and space waves from the viewpoint of scattering, thus the analysis is tremendously simplified.  相似文献   

14.
Vaccination via the oral administration of an antigen faces many challenges, including gastrointestinal (GI) proteolysis and mucosal barriers. To limit GI proteolysis, a biomimetically mineralized aluminum‐based metal–organic framework (Al‐MOF) system that is resistant to ambient temperature and pH and can act synergistically as a delivery vehicle and an adjuvant is synthesized over a model antigen ovalbumin (OVA) to act as armor. To overcome mucosal barriers, a yeast‐derived capsule is used to carry the Al‐MOF‐armored OVA as a “Trojan Horse”‐like transport platform. In vitro experiments reveal that the mineralization of Al‐MOFs forms an armor on OVA that protects against highly acidic and degradative GI conditions. However, the mineralized Al‐MOFs can gradually disintegrate in a phosphate ion‐containing simulated intracellular fluid, slowly releasing their encapsulated OVA. In vivo studies reveal that the “Trojan Horse”‐like transport platform specifically targets intestinal M cells, favoring the transepithelial transport of the Al‐MOF‐armored OVA, followed by subsequent endocytosis in local macrophages, ultimately accumulating in mesenteric lymph nodes, yielding long‐lasting, high‐levels of mucosal S‐IgA and serum IgG antibodies. Such an engineered delivery platform may represent a promising strategy for the oral administration of prophylactic or therapeutic antigens for vaccination.  相似文献   

15.
Understanding the interactions at interfaces between the materials constituting consecutive layers within organic thin‐film transistors (OTFTs) is vital for optimizing charge injection and transport, tuning thin‐film microstructure, and designing new materials. Here, the influence of the interactions at the interface between a halogenated organic semiconductor (OSC) thin film and a halogenated self‐assembled monolayer on the formation of the crystalline texture directly affecting the performance of OTFTs is explored. By correlating the results from microbeam grazing incidence wide angle X‐ray scattering (μGIWAXS) measurements of structure and texture with OTFT characteristics, two or more interaction paths between the terminating atoms of the semiconductor and the halogenated surface are found to be vital to templating a highly ordered morphology in the first layer. These interactions are effective when the separating distance is lower than 2.5 dw, where dw represents the van der Waals distance. The ability to modulate charge carrier transport by several orders of magnitude by promoting “edge‐on” versus “face‐on” molecular orientation and crystallographic textures in OSCs is demonstrated. It is found that the “edge‐on” self‐assembly of molecules forms uniform, (001) lamellar‐textured crystallites which promote high charge carrier mobility, and that charge transport suffers as the fraction of the “face‐on” oriented crystallites increases.  相似文献   

16.
The results presented in this paper are related to an experimental study that has the aim to evidence the formation of “latent gate oxide damages” in medium voltage power MOSFETs during the impact with energetic particles. The understanding of these “latent defectiveness” can be an helpful aid in the comprehension of the mechanisms of breach of the oxide layer of MOS structures induced by single energetic particles impact (single event gate rupture). To properly detect the presence of “latent damages” we have developed a high resolution experimental set-up and identified an appropriate region in which the device have to be biased in order to trigger this kind of damage.  相似文献   

17.
18.
A sharp rise in lumen degradation was observed for packaged high power LEDs during the initial period of operation under high humidity and temperature conditions, and the degradation reaches a peak value, followed by a “recovery” in lumen output, a sign of reliability rejuvenation. The time to reach the peak degradation is shorter with higher relative humidity. Scanning acoustic microscopy (SAM) tomography is employed to study the effect of moisture at different time intervals. With the help of moisture diffusion modeling using ANSYS simulation, the phenomenon is found to be due to the increasing moisture absorption of silicone resulting in subsequent light scattering as light is emitting from the dice. The “recovery” is the result of moisture absorption by die attach material that sucks the moisture from the silicone. Thus the “recovery” of lumen degradation is actually associated with the degradation in the internal structure of the LED package which is not reversible. C-SAM results are in accordance with the simulation and experimental results. The implication of this finding on temperature–humidity test of high power LEDs is described, and the material parameters of silicone to reduce this initial degradation are also presented.  相似文献   

19.
The term “bionics” is synonymous with the term “biomimetics” and in this context refers to the integration of human engineered devices to take advantage of functional mechanisms and structures resident in nature. The use of electrical conductors to transmit charge into and out of biological systems to affect biological processes has been the source of great scientific interest. This has inspired many to explore the possible use of electrical stimulation in promoting positive health outcomes. Advances in medical bionics technology are dependent upon eliciting precise control of the electrical energy to deliver beneficial health outcomes. The advent of carbon‐based organic conductors now provides the platform for unprecedented possibilities by which the electrical energy can be used to modulate the function of medical devices. The use of organic conductors in the field of bionics, and in particular medical bionics, as that involved with the development of devices that enable the effective integration of biology (nature) and electronics to achieve a targeted functional outcome is explored.  相似文献   

20.
The origin of the roughness of Fin FET channel sidewalls in the heterointegration scheme was discussed. It is shown that its presence is caused by the original roughness of the Si sidewalls of the “fin” structures formed during plasma etching. A number of processing steps affecting the morphology of the Si fin structures were analyzed. The smoothing of the resistive polymeric mask in the HBr-containing plasma, distributed trimming in the layered mask, and control of the temperature conditions are among these technologies.  相似文献   

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