分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Antireflection (AR) coatings that exhibit multi- functional characteristics, including high transparency, robust resistance to moisture, high hardness, and antifogging proper- ties, were developed based on hollow silica−silica nano- composites. These novel nanocomposite coatings with a closed-pore structure, consisting of hollow silica nanospheres (HSNs) infiltrated with an acid-catalyzed silica sol (ACSS), were fabricated using a low-cost sol−gel dip-coating method. The refractive index of the nanocomposite coatings was tailored by controlling the amount of ACSS infiltrated into the HSNs during synthesis. Photovoltaic transmittance (TPV) values of 96.86− 97.34% were obtained over a broad range of wavelengths, from 300 to 1200 nm; these values were close to the theoretical limit for a lossy single-layered AR coating (97.72%). The nanocomposite coatings displayed a stable TPV, with degradation values of less than 4% and 0.1% after highly accelerated temperature and humidity stress tests, and abrasion tests, respectively. In addition, the nanocomposite coatings had a hardness of approximately 1.6 GPa, while the porous silica coatings with an open-pore structure showed more severe degradation and had a lower hardness. The void fraction and surface roughness of the nanocomposite coatings could be controlled, which gave rise to near-superhydrophilic and antifogging characteristics. The promising results obtained in this study suggest that the nanocomposite coatings have the potential to be of benefit for the design, fabrication, and development of multifunctional AR coatings with both omnidirectional broadband transmission and long-term durability that are required for demanding outdoor applications in energy harvesting and optical instrumentation in extreme climates or humid conditions.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Layered bismuth oxyhalide nanomaterials have received much more interest as promising photocatalysts because of their unique layered structures and high photocatalytic performance, which can be used as potential inorganic photosensitizers in tumor photodynamic therapy (PDT). In recent years, photocatalytic materials have been widely used in PDT and photothermal therapy (PTT) as inorganic photosensitizers. This investigation focuses on applying layered bismuth oxyhalide nanomaterials toward cancer PDT, an application that has never been reported so far. The results of our study indicate that the efficiency of UV- triggered PDT was highest when using BiOCl nanoplates followed by BiOCl nanosheets, and then TiO2. Of particular interest is the fact that layered BiOCl nanomaterials showed excellent PDT effects under low nanomaterial dose (20 μg mL−1) and low UV dose (2.2 mW cm−2 for 10 min) conditions, while TiO2 showed almost no therapeutic effect under the same parameters. BiOCl nanoplates and nanosheets have shown excellent performance and an extensive range of applications in PDT.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Porous silicon/carbon (Si/C) structure has been proved of great help to enhance the electrochemical cycling performance of Si-based anode materials. Current fabrication of porous Si based anodes usually relies on the complicated chemical etching process with unavoidable pollution problem. Herein, a na- noporous Si/C composite was successfully fabricated by a facile spray drying and carbonization process. The environmentally benign NaCl is used as the sacrificing template for the generation of embedded nanopores, which can be easily removed by routine washing process. The as-prepared nanoporous Si/C anode exhibits a high reversible specific capacity of around 900 mAh g 1 with 78.2% capacity retention after 100 cycles. This synthetic method paves a simple and environment-friendly way to build porous Si based anode with improved electrochemical performance which is significantly important for the in- dustrial production.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Novel ionic binders based on sulfonated polyether ether ketones and polysulfone backbones, bearing pendant lithiated fluorinated sulfonimide groups (SPEEK-PSI-Li and PSU-PSI-Li) were developed. Their performance in high performance silicon (Si) nano-particle anodes was studied in comparison with conventional binders such as lithiated sulfonated poly(ether-ether-ketone) containing fluorinated sulfonic acid side chains (SPEEK-PSA-Li), poly(vinylidene) difluoride (PVDF), sodium carboxymethyl cellulose (CMC) and alginate. Much superior to other anode binders, the ionic conducting SPEEK-PSI-Li binders could not only provide good adhesion properties, but also effectively reduce the over-potential during rapid charge and discharge cycles. When cycled at a current of 400 mA g 1, these anodes could maintain above 2000 mA h g 1 after 50 cycles. Even when cycled at a high current rate of 2000 mA g 1, the anodes with SPEEK-PSI-Li binders could be cycled above 500 mA h g 1 in 50 cycles. The superior performance of the novel SPEEK-PSI-Li binders could be attributed to their high cohesion capability, low solubility in electrolytes, high adaptability to volume fluctuation and high ionic conducting capability resulting from of the co-existence of flexible PEEK backbones, flexible fluorinated ether side chains, ionic transporting sulfonate groups, and pentadentate super ionic sulfonimide groups in the molecule structures.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-04-06
摘要: We report the synergistic optimization of the thermoelectric properties in p-type Bi0.48Sb1.52Te3 by the additional graphene. Highly dense Bi0.48Sb1.52Te3 + graphene (x wt%, x = 0, 0.05, 0.1 and 0.15) composites have been synthesized by zone-melting follo
分类: 材料科学 >> 材料科学(综合) 提交时间: 2017-05-09
摘要: Perylene tetracarboxylic anhydride (PTCDA) was reacted with 6-aminocaproic acid to form the corresponding perylene bisimide (PBI). PBI was used as the foundation for oligomerisation of glycidol in a ring-opening reaction of glycidol leading to a hyper branched, water-soluble glycidol derivative of perylene (PBI-HPG). PBI-HPG was bound to the reduced graphene oxide via p–p stacking resulting in a compound termed PBI-HPG/RGO. The structure and morphology of PBI-HPG/RGO were investigated by infrared spectroscopy (FT-IR), wide angle X-ray diffractometry (WAXD), transmission electron microscopy (TEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). PBI- HPG/RGO was blended at different loadings in order to improve the thermal and mechanical properties of epoxy composites. The maximum Tg of the epoxy composites was about 20 C and the decomposition temperature (Td) was 26 C higher than that of neat epoxy. The incorporation of PBI- HPG/RGO yields a material with an impact strength of 39.6 kJ m 2 and a tensile strength at 0.7 wt%. It increased by 50.8% and 62.3%, respectively, compared to the neat epoxy.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: A green facile scalable method inspired by polymeric dental restorative composite is developed to synthesize TiO2/carbon nanocomposites for manipulation of the intercala- tion potential of TiO2 as lithium-ion battery anode. Poorly crystallized TiO2 nanoparticles with average sizes of 4−6 nm are homogeneously embedded in carbon matrix with the TiO2 mass content varied between 28 and 65%. Characteristic discharge/ charge plateaus of TiO2 are significantly diminished and voltage continues to change along with proceeding discharge/charge process. The tap density, gravimetric and volumetric capacities, and cyclic and rate performance of the TiO2/C composites are effectively improved.
提交时间: 2017-04-06
摘要: Aluminum hypophosphite (AHP) was introduced into polylactide/intumescent flame retardant (PLA/IFR) systems by melt blending. The flame retardant and thermal properties of the PLA composites were investigated. The results suggest that a synergistic effect
提交时间: 2017-05-02
摘要: White TiO2 nanoparticles [NPs] have been widely used for cancer photodynamic therapy based on their ultraviolet light-triggered properties. To date, biomedical applications using white TiO2 NPs have been limited, since ultraviolet light is a well-known mu