Preparation and characterizations of tungsten oxide electrochromic nanomaterials

Nanoscaled tungsten oxide thin films were fabricated by galvanostatic electrodeposition. The effect of preparation parameters such as tungsten ions concentration, pH, current density and annealing on the properties and performance of WO₃ thin films electrochromic materials was investigated. XRD, SEM–EDS, TEM, FTIR, UV–VIS spectrophotometry, and electrochemical measurements were utilized to characterize the structural and compositional properties as well as the electrochromic behaviour of the prepared thin films. Triclinic WO₃ structure was prepared at 0.1 M W⁺ and current density of 0.5 mA cm⁻², while at 0.2 M W⁺ and 1 mA cm⁻², orthorhombic structure was revealed. High energy gap of 3.5 eV with diffusion coefficient of 6.81 × 10⁻¹¹ cm² S⁻¹ and coloration efficiency of 62.68 cm² C⁻¹ were obtained for the films prepared at pH 2, 1 mA cm⁻², and 0.1 M W⁺.     

Preparation and characterizations of Mg-Ca alloys as degradable biomaterials

Mg-Ca alloys have been proposed to be a new candidate for biodegradable metal materials in the present study.Mg-1Ca,Mg-5Ca and Mg-20Ca(wt%)have been prepared and the primary properties related to their biomedical application have been investigated by X-ray diffraction,SEM observation,tensile,electrochemical and immersion tests.The experimental results show that with the increase of Ca concentration,the working ability of Mg-Ca alloy becomes worse.Only Mg-1Ca and Mg-5Ca alloy specimens can be hot rolled i...     

Metallic glass nanotube arrays: Preparation and surface characterizations

In this study, we fabricated first-ever metallic glass nanotubes (MGNTs) in a distinct pattern on a Si substrate, by sputter-depositing a coating of metallic glass (Zr₅₅Cu₃₀Al₁₀Ni₅) over a contact-hole array template created in photoresist. The resulting nanotubes were 500 or 750?nm in height with a diameter of 500 or 750?nm and wall thickness ranging from 44?nm to 103?nm. The structure of the nanotubes was preserved by the high strength and ductility of the metallic glass during the removal of the photoresist template under ultrasonic vibration. We observed an increase in the hydrophobicity of the MGNT with an increase in the thickness of the walls, with the thickest walls presenting an apparent contact angle of 139°. The hydrophobicity is due to air trapped within the tubes, which prevents the intrusion of water into the nanostructures. We also observed thermal-response behavior on the surface of the MGNT array. Surface cooling produced negative pressure within the nanochambers, which created a sucking force against the water droplets. Surface heating produced positive pressure within the nanochambers, which actually lifted the droplets. This thermal-response behavior was shown to be reversible for at least five cycles between 25 and 55?°C. The MGNT created adhesion forces reaching 14.2?N?cm^?2, which was sufficient to secure the water droplets even when the surface was tilted or completely inverted. The MGNT array in this study represents a biomimetic analog with switchable contact interface, the behavior of which can be controlled simply by altering the surface temperature.     

Preparation of regularly ordered Ge quantum dot lattices in amorphous matrices

We compare structural and optical properties of Ge quantum dot lattices in amorphous silica matrix obtained by two recently published techniques for the preparation of regularly ordered quantum dot lattices in amorphous matrices. The first technique is self-ordering growth of (Ge + SiO₂)/SiO₂ multilayer at an elevated substrate temperature where diffusion and surface morphology effects drive the self-ordering. The second one is irradiation of (Ge + SiO₂)/SiO₂ multilayer by oxygen ions. The multilayer used for the irradiation is grown at room temperature in this case, resulting with no Ge clusters after the deposition process. The irradiation causes clustering of Ge and ordering of Ge quantum dots in the irradiation direction. We show that the size of the dots and their arrangement can be easily manipulated by the preparation parameters. The structural properties of the films prepared by these methods affect the quantum confinement of the charge carriers which is visible in the absorption properties of the films.     

Preparation and ac electrical characterizations of Cd doped SnO2 nanoparticles

Nanoparticles (NPs) of the Sn_1?xCd_xO₂ (0.0 ≤ x ≤ 0.04) were synthesized through soft chemistry method. These NPs were characterized for structural, morphological and electrical properties by X-ray diffraction, High resolution transmission electron microscopy and dielectric spectroscopy techniques respectively. Structural analysis confirms that all the NPs are having single phase rutile tetragonal structure. The NPs are of spherical shape and average size of these is found to decrease with Cd doping. Dielectric permittivity and AC conductivity of all the NPs were evaluated as a function of frequency and composition at room temperature. The frequency response of ε_r, ε_i, tan δ and σ _ac show that the dispersion is due to the interfacial polarization and these parameters decrease with doping of Cd in the SnO₂ matrix. The possible correlation between observed dielectric properties and size of NPs, and hence disorder in the system are explored.     

Preparation and characterizations of antibacterial PET-based hollow fibers containing silver particles

In this work, we have developed a facile differential pressure route to prepare PET-based hollow fibers containing silver particles (Ag/PET hollow fibers). X-ray Diffraction and Scanning Electron Microscopy were used to confirm the existence of silver particles, and the results showed that 0.1-0.5 μm silver particles were incorporated in the inner side-wall of the hollow portion. Inductively Coupled Plasma Atomic Emission Spectrometer was applied to detect the release behavior of silver ions from various Ag/PET hollow fibers. And the results showed that the release behavior of silver ions was depended on time and the length of the fibers, which may be explained by the water uptake property of the Ag/PET hollow fibers.     

氧化石墨烯纳米带/TPU复合材料薄膜制备及性能表征

采用氧化法将碳纳米管纵向切割成氧化石墨烯纳米带,利用溶液成形在涂膜机上制备氧化石墨烯纳米带/TPU复合材料薄膜。FT-IR、拉曼光谱、XRD、FE-SEM、TEM等测试表明,碳纳米管成功地被纵向切割成带状结构的氧化石墨烯纳米带。力学测试表明,当氧化石墨烯纳米带用量为2%(质量分数)时,复合材料薄膜弹性模量与拉伸强度相比TPU薄膜提高了160%与123%。氧气透过率测试表明当氧化石墨烯纳米带用量为2%(质量分数)时,复合材料薄膜氧气透过率降低77%,阻隔性能明显提高。     

含有序贯通孔道液晶聚合物膜的制备及其无水质子传导

利用含苯甲酸（6OBA）和苯乙烯基吡啶（6SzMA）基团的单体分子间氢键作用诱导形成超分子液晶,与交联剂（C6H）混合后通过原位光聚合,在平行取向条件下制备功能液晶聚合物膜,获得有序贯通的传导通道,并应用于无水质子传导,进一步通过H₃PO₄掺杂实现质子传导性能强化。运用FT-IR、POM、TGA、DSC、2D-SAXS、高分辨TEM和EIS对其氢键、液晶特性、微观结构和无水质子传导性能进行表征。结果表明,6OBA与6SzMA分子间形成氢键诱导产生近晶相,平行取向条件下聚合后,近晶相层结构固化获得纳米尺度规整排布的有序孔道,在无水条件下170℃时其质子传导率为7.1×10^-9 S/cm。H₃PO₄掺杂后以分子簇的形式存在,充足的质子源和增强的氢键网络使得传导性能显著提升超4个数量级,170℃时达到3.2×10^-4 S/cm。     

多元醇还原制备纳米Co粉及其磁性的研究

采用二价钴盐为前驱物,1,2-丙二醇为还原剂,用液相还原法制备了晶粒尺寸约为10～13nm、具有面心立方(β相)结构的纯度高、粒度均匀的纳米钴粉,运用XRD、TEM等分析方法对制备的纳米钴粉进行物相和结构形貌的表征,初步研究了多元醇法还原Co纳米粉的反应机理.采用VSM对纳米钴粉进行磁学性能的表征.结果表明,所制备的纳米Co粉在室温下具有铁磁性,并且矫顽力不高(6.282×103A/m).     

Transparent with wide band gap InZnO nano thin film: Preparation and characterizations

Novel indium zinc oxide (InZnO) thin film of 100 nm thickness was prepared onto pre-cleaned glass plate by thermal evaporation technique from InZnO nanoparticles. The metal oxide (In–O and Zn–O) bond and In, Zn and O elements present in the films were confirmed by Fourier transform infrared spectroscopy and energy dispersive X-ray spectroscopy. The X-ray diffraction patterns revealed the mixed phase of cubic In₂O₃ and wurzite-hexagonal ZnO structure. SEM images showed smooth surface with uniform distribution of grains (201–240 nm) over the entire film surface. High transparency and low absorption obtained from optical study. The band gap energy was evaluated to be about 3.46–3.55 eV by Tauc’s plot. The structure, smooth surface and high transparency with wide band gap energy lead the thermally evaporated InZnO nano thin film to be used for transparent layer in optoelectronic devices in the future.     

HAp/SiO2复合陶瓷材料的制备及体外生物活性

HAp和SiO2的混合粉末压制成型后,在1200℃下烧结得到含5.0%(质量分数)SiO2的HAp/SiO2生物陶瓷复合材料。烧结体的XRD及FT-IR分析结果表明,SiO2的添加促进了HAp发生热分解。其主要物相为α-TCP、HAp、Ca2P2O7以及生物玻璃(bioglass,BG)等。体外生物活性实验结果显示,样品浸泡在模拟体液(SBF)中24h后,表面出现花瓣状磷灰石沉积物,72h后进而生成板状沉积物,120h后在样品表面覆盖了较厚的类骨磷灰石层,经XRD测试分析表明,该层主要为碳酸羟基磷灰石(HCA)。制备的HAp-5.0%(质量分数)SiO2生物陶瓷复合材料具有比纯HAp更加优越的体外生物活性,可期待作为一种新的骨修复材料。     

硅烷改性醇溶性丙烯酸酯胶粘剂的制备和性能

利用乙烯基三乙氧基硅烷对醇溶性聚丙烯酸酯进行了改性,合成了一种可用于塑料薄膜的环保型胶粘剂。讨论了有机硅单体的加入对聚合反应、胶粘剂粘接强度的影响,并探讨了影响粘接强度的因素。研究表明,有机硅单体的最佳用量为3%,过量的有机硅会导致材料结构缺陷,从而影响粘接强度。     

水溶性甲壳素/纤维素共混膜的制备及性能研究

将水溶性甲壳素与用氢氧化钠-尿素-硫脲体系溶解的纤维素共混制膜.红外光谱、扫描电镜、透射比分析表明,当水溶性甲壳素浓度达到10%～15%时,水溶性甲壳素与纤维素具有较好的相容性.共混膜的吸湿率和保湿率分别达到32%和55%左右,并具有良好的抗茵性.     

Preparation and characterizations of polyaniline (PANI)/ZnO nanocomposites film using solution casting method

Polyaniline (PANI)-ZnO nanoparticles composites film has been successfully fabricated by solution casting technique on glass substrate in which ZnO nanopowder was prepared via auto combustion method and used as inorganic materials. The as-grown nanocomposites film has been characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Transmission electron microscopy (TEM) and Atomic Force Microscopy (AFM) for their structural and morphological characterizations. X-ray diffraction studies of as-grown film showed the reflection of ZnO nanoparticles along with a broad peak of PANI. The AFM study of the film shows the incorporation of ZnO nanoparticles into the polymer matrix which was further supported by roughness measurement. TEM images showed that the size of ZnO nanoparticles in the nanocomposites increase from ~ 35 nm to ~ 45 nm, indicating the interaction of nanoparticles with PANI molecular chains. FTIR spectra showed a band at 501 cm⁻¹ due to ZnO nanoparticles while the hydrogen bonding between the amine group of PANI and ZnO nanoparticles had been confirmed from the presence of the absorption band at 1148 cm⁻¹.     

Preparation of regularly structured nanotubular TiO2 thin films on ITO and their modification with thin ALD-grown layers

Nanotubular titanium dioxide thin films were prepared by anodization of titanium metal films evaporated on indium tin oxide (ITO) coated glass. A facile method to enhance the adhesion of the titanium film to the ITO glass was developed. An optimum thickness of 550 nm for the evaporated titanium was found to keep the film adhered to ITO during the anodization. The films were further modified by growing amorphous titania, alumina and tantala thin films conformally in the nanotubes by atomic layer deposition (ALD). The optical, electrical and physical properties of the different structures were compared. It was shown that even 5 nm thin layers can modify the properties of the nanotubular titanium dioxide films.     

水溶性蒙脱土改性聚丙烯酸钠的合成及性能研究

采用水溶液插层聚合法制备水溶性蒙脱土改性聚丙烯酸钠(PNaAA)复合材料.研究了溶液pH值、有机蒙脱土及APS/SFS/AIBA引发体系用量对产物特性黏数及溶解时间的影响,并对其热稳定性、溶液性能与未改性聚丙烯酸钠进行了比较.结果表明:以自制有机蒙脱土用原位聚合方法制备的改性聚丙烯酸钠特性黏数可提高21%,并能够在其耐降解、耐剪切和耐高温能力上有较大提高.     

聚噻吩/纳米MnO2复合材料的制备表征及电化学性能

纳米二氧化锰（MnO₂）作为超级电容材料已被广泛研究。为了改善其充放电性能,采用原位化学氧化聚合法制备聚噻吩/纳米MnO₂ （PTh/MnO₂）复合材料,对纳米MnO₂进行性能改性。通过改变聚噻吩在PTh/MnO₂复合材料中的掺杂量,制备出一系列的复合材料。采用傅里叶转换红外光谱（FIIR）、X射线衍射仪（XRD）、场发射扫描电子显微镜（FE-SEM）和透射电子显微镜（TEM）对PTh/MnO₂复合材料的化学性能、晶体结构以及表面形貌等进行了详细考察。接着采用CT001A型电池测试系统对以PTh/MnO₂复合材料做负极所制得的密封扣式电池进行了充放电性能测试。结果表明,MnO₂和聚噻吩在不同的PTh/MnO₂复合材料中形貌各异。当聚噻吩含量为8wt%~10wt%时,MnO₂在PTh/MnO₂复合材料中分布最为均匀;当聚噻吩含量较高时,MnO₂的形貌受到严重影响,其原来的管状结构接近消失。聚噻吩含量的不同,同样也影响了电池的充放电性能。当聚噻吩的含量为20wt%时,在循环20次后,电池的平衡容量为最高,可达700 mAh/g。这明显高于以纳米MnO₂为负极时的电池容量。由此可见,聚噻吩对纳米MnO₂的充放电性能具有明显的增强作用。该研究为PTh/MnO₂复合材料作为电池负极材料的使用提供了实验基础。