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Crystalline Fe/MnO@C core–shell nanocapsules inlaid in porous amorphous carbon matrix(FMCA)was synthesized successfully with a novel confinement strategy.The heterogeneous Fe/MnO nanocrystals are with approximate single-domain size which gives rise to natural resonance in 2–18 GHz.The addition of MnO2 confines degree of graphitization catalyzed by iron and contributes to the formation of amorphous carbon.The heterogeneous materials composed of crystalline–amorphous structures disperse evenly and its density is significantly reduced on account of porous properties.Meanwhile,adjustable dielectric loss is achieved by interrupting Fe core aggregation and stacking graphene conductive network.The dielectric loss synergistically with magnetic loss endows the FMCA enhanced absorption.The optimal reflection loss(RL)is up to−45 dB,and the effective bandwidth(RL<−10 dB)is 5.0 GHz with 2.0 mm thickness.The proposed confinement strategy not only lays the foundation for designing high-performance microwave absorber,but also offers a general duty synthesis method for heterogeneous crystalline–amorphous composites with tunable composition in other fields. 相似文献
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Dr. Kartheek Katta Dr. Dmitry Busko Prof. Katharina Landfester Dr. Stanislav Baluschev Dr. Rafael Muñoz-Espí 《Israel journal of chemistry》2018,58(12):1356-1362
We demonstrate that the efficiency under ambient conditions of optically active molecules encapsulated in polymer nanocapsules can be significantly improved by depositing an inorganic layer onto the polymeric shell. A triplet-triplet annihilation upconversion (TTA-UC) system consisting of a porphyrin derivative and perylene is used as a representative case. Different inorganic materials are deposited on the surface of functionalized polymer nanocapsules synthesized by free-radical polymerization in miniemulsion. First, a silicate clay with formula [Si8(Mg5.45Li0.4)O20(OH)4]Na0.7 is deposited on the surface of positively charged polystyrene nanocapsules via layer-by-layer deposition. Second, controlled in situ mineralization of hydroxyapatite and cerium(IV) oxide are carried out on the surface of negatively charged polystyrene nanocapsules. In both cases the inorganic materials on the nanocapsule surface act as a scavenger and avoid the entry of oxygen from the external environment. By avoiding the entry of oxygen, the photo-oxidation process of perylene molecules is avoided within the system, and an increase in the TTA-UC properties occurs. 相似文献
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超临界流体抗溶剂法制备叶黄素/羟丙甲纤维素邻苯二甲酸酯纳米微胶囊 总被引:3,自引:0,他引:3
Lutein was nano-encapsuled with hydroxypropylmethyl cellulose phthalate (HPMCP) to maintain its bioactivity and to avoid thermal/light degradation. Supercritical antisolvent precipitation was applied to prepare lutein/HPMCP nano-capsule. The effects of several operating parameters on the yield, lutein loading, encapsulation efficiency, particle size and particle size distribution of the nanocapsule were investigated. The mean diameter of nanocapsules ranged from 163 nm to 219 nm under appropriate experimental conditions. The result of scanning electron microscope showed that the nanocapsules were nearly spherical. The highest yield reached 95.35% when the initial concentration of lutein was saturated. The highest lutein loading of 15.80% and encapsulation efficiency of 88.41% were obtained under the conditions of 11 MPa, 4061616;C and CHPMCP︰Clutein 5︰l. The results may pro-mote the application of lutein in food industry. 相似文献
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Jian Gao Jieyi Yu Lei Zhou Javid Muhammad Xinglong Dong Yinong Wang Hongtao Yu Xie Quan Shaojie Li Youngguan Jung 《Nano Research》2017,10(8):2644-2656
Carbon-coated SiC@C nanocapsules (NCs) with a hexagonal platelet-like morphology were fabricated by a simple direct current (DC) arc-discharge plasma method.The SiC@C NCs were monocrystalline,120-150 nm in size,and approximately 50 nm thick.The formation of the as-prepared SiC@C NCs included nucleation of truncated octahedral SiC seeds and subsequent anisotropic growth of the seeds into hexagonal nanoplatelets in a carbon-rich atmosphere.The disordered carbon layers on the SiC@C NCs were converted into SiO2 shells of SiC@SiO2 NCs by heat treatment at 650 ℃ in air,during which the shape and inherent characteristics of the crystalline SiC core were obtained.The interface evolution from carbon to SiO2 shells endowed the SiC@SiO2 NCs with enhanced photocatalytic activity due to the hydrophilic and transparent nature of the SiO2 shell,as well as to the photosensitive SiC nanocrystals.The band gap of the nanostructured SiC core was determined to be 2.70 eV.The SiC@SiO2 NCs degraded approximately 95% of methylene blue in 160 min under visible light irradiation. 相似文献
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利用直流电弧等离子体法在甲烷气氛中制备碳包覆磁性镍纳米胶囊(Carbon-coated Ni nanocapsules,Ni(C)NCs),将它作为电磁波吸收剂,按照质量比10%、20%、30%和40%与有机石蜡基体复合,在0.1~18GHz范围内测定其复介电常数和复磁导率,并对其电磁波响应特性及吸收机制进行了研究。研究结果表明,Ni(C)纳米胶囊具有明显的极化损耗特征,其介电常数在低频范围内随频率提高而急剧衰减,而磁导率具有宽化的多重共振峰;随着Ni(C)纳米胶囊添加量的增加,其介电常数逐渐增加,其复磁导率实部和虚部分别在0.1~8GHz、0.1~10GHz出现增加,而在8~18GHz和10~18GHz范围内出现实部减小和虚部平缓变化的特征。根据极化、涡流以及反射损耗的理论分析,发现Ni(C)纳米胶囊以介电损耗为主,并对相关机制进行了探讨。 相似文献
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Sheng Liang Yang Liu Xin Jin Gan Liu Jing Wen Linlin Zhang Jie Li Xubo Yuan Irvin S. Y. Chen Wei Chen Hui Wang Linqi Shi Xinyuan Zhu Yunfeng Lu 《Nano Research》2016,9(4):1022-1031
Protein therapy, wherein therapeutic proteins are delivered to treat disorders, is considered the safest and most direct approach for treating diseases. However, its applications are highly limited by the paucity of efficient strategies for delivering proteins and the rapid clearance of therapeutic proteins in vivo after their administration. Here, we demonstrate a novel strategy that can significantly prolong the circulation time of therapeutic proteins as well as minimize their immunogenicity. This is achieved by encapsulating individual protein molecules with a thin layer of crosslinked phosphorylcholine polymer that resists protein adsorption. Through extensive cellular studies, we demonstrate that the crosslinked phosphorylcholine polymer shell effectively prevents the encapsulated protein from being phagocytosed by macrophages, which play an essential role in the clearance of nanoparticles in vivo. Moreover, the polymer shell prevents the encapsulated protein from being identified by immune cells. As a result, immune responses against the therapeutic protein are effectively suppressed. This work describes a feasible method to prolong the circulation time and reduce the immunogenicity of therapeutic proteins, which may promote the development and application of novel protein therapies in the treatment of diverse diseases. 相似文献
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本文采用细乳液聚合的方法,通过添加功能单体,合成了表面带有功能基团的聚苯乙烯/丙烯酸空心纳米胶囊。选用了十六烷(HD)及甲基异丁酮(MIBK)两种不同的疏水物质作为助稳定剂,分析了助稳定剂种类及用量对聚苯乙烯/丙烯酸共聚物颗粒形貌的影响。TEM观察发现,当单体用量与助稳定剂质量比为1:1时,可得到大量具有空心结构的粒径为100nm左右的乳胶粒子。采用MIBK作为助稳定剂制备的纳米胶囊可作为载体封装油溶性染料以合成染料/共聚物复合纳米色素,并表现出较好的光稳定性能。而HD作为助稳定剂使用时,染料无法在油相中均匀分散,最终导致无法得到稳定乳液。 相似文献
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Multifunctional Carbon–Silica Nanocapsules with Gold Core for Synergistic Photothermal and Chemo‐Cancer Therapy under the Guidance of Bimodal Imaging 下载免费PDF全文
Linlin Li Chuanfang Chen Huiyu Liu Changhui Fu Longfei Tan Shunhao Wang Shiyan Fu Xi Liu Xianwei Meng Hong Liu 《Advanced functional materials》2016,26(24):4252-4261
Carbon‐based nanomaterials have been developed for photothermal cancer therapy, but it is still a great challenge to fabricate their multifunctional counterparts with facile methods, good biocompatibility and dispersity, and high efficiency for cancer theranostics. In this work, an alternative multifunctional nanoplatform is developed based on carbon–silica nanocapsules with gold nanoparticle in the cavity (Au@CSN) for cancer theranostics. The encapsulated chemodrug doxorubicin can be released from the Au@CSN with mesoporous and hollow structure in a near‐infrared light and pH stimuli‐responsive manner, facilitating spatiotemporal therapy to decrease off‐target toxicity. The nanocapsules with efficient photothermal conversion and excellent biocompatibility achieve a synergistic effect of photothermal and chemotherapy. Furthermore, the nanocapsules can act as a multimodal imaging agent of computed tomography and photoacoustic tomography imaging for guiding the therapy. This new design platform can provide a promising strategy for precise cancer theranostics. 相似文献
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Cancer Therapy: Multifunctional Carbon–Silica Nanocapsules with Gold Core for Synergistic Photothermal and Chemo‐Cancer Therapy under the Guidance of Bimodal Imaging (Adv. Funct. Mater. 24/2016) 下载免费PDF全文