聚氨酯与铁电陶瓷粉复合物的电致感应性能研究

利用双辊制备了一系列热塑性弹性体聚氨酯（PU）和铁电钛酸锆酸铅盐（PZT）的电感应PZT／PU复合物。X－衍射和SE镜结果显示,复合物中,在铁电相中PZT陶瓷粉呈现结晶态并且均匀分布在PU基体中,复合物的弹性模量和相对电容率随着复合物中PZT体积分数增加而升高,在高压电场下,低PZT含量的复合物呈现负的电致伸缩应力,当PZT体积分数增加到6％以上时,在某个临界电场下,复合物呈现出电致伸缩应力反转的特性,即电致伸缩应力从负转变为正,并且发生应力反转的临界电场随着复合物中PZT体积分数的增加而降低,PU的电致伸缩特性与PZT在高电场下极化反转效应结合,导致了PZT／PU复合物这种有趣的性能,因此PZT／PU复合物将在高电压场方面作为传感器开关材料得到广泛应用。     

Fe3O4／TiO2磁性催化剂的制备及在污水治理中的应用

以纳米Fe3O4为载体,以钛酸四丁酯为前躯体,用溶胶-凝胶法在Fe3O4表面包覆TiO2层,制备Fe3O4／TiO2光催化材料．透射电镜（TEM）、X射线衍射（XRD）、X射线光电子能谱（XPS）和红外光谱（IR）分析表明,TiO2在纳米Fe3O4颗粒表面形成很好的包覆层．用Fe3O4／TiO2光催化材料对工业上难处理...     

几种钙钛矿型晶体极化性能的从头算分子动力学研究

对具有钙钛矿结构的钛酸钡(BT)、钛酸铅(PT)、锆酸铅(PZ)、三种钛/锆比例的锆钛酸铅(PZT)和镁铌酸铅(PMN)的部分构型建立了复晶胞模型, 并运用从头算分子动力学方法CPMD对其极化性能进行了模拟. 计算结果表明自发极化强度与B格点原子类型和其偏离所处氧笼中心距离有关; d₃₃/χ_e最大值: 25%/75% (Ti/Zr)的PZT的出现在(111)方向, 其它晶体均出现在(001)方向; PZ, PZT, PMN的d₃₃/χ_e值较高; g₃₃×χ_e最大值出现在(001)或(110)方向; PT和PZT的 g₃₃×χ_e值较大.     

Pt（Cu）-CdS／钛酸纳米管光催化转化CO2和H2O的研究

以商业P25为前躯体,用强碱水热超声法合成钛酸纳米管（TiNT）,以其为载体采用离子交换法制备CdS复合钛酸纳米管（CdS／TiNT）,再用浸渍法负载共催化剂Pt或Cu．对上述样品进行光催化转化CO2和H2O的实验研究,并采用透射电子显微镜（TEM）、X射线衍射（XRD）、紫外可见漫反射（UV—Vis DRS）、比表面...     

PZT/P(VDF-TrFE)纤维膜的静电纺丝制备及其性能

以锆钛酸铅压电陶瓷(PZT)和聚(偏氟乙烯-三氯乙烯)(P(VDF-TrFE))共聚物为原料,利用静电纺丝的方法制备了PZT/P(VDF-TrFE)纤维膜。用扫描电子显微镜、精密阻抗测试仪和拉力试验机对纤维膜的形貌、电学性能、力学性能进行了表征。结果表明,适当地提升PZT的质量分数能有效提升纤维膜中纤维丝的均匀性。当PZT质量分数为4%时,纤维丝的均匀性最佳;静电纺丝方法能够得到低介电常数的PZT/P(VDF-TrFE)纤维膜,并且通过调节PZT的质量分数,可以保证纤维膜的介电常数在一定范围内变化。PZT颗粒的加入能够有效调节PZT/P(VDFTrFE)纤维膜的拉伸强度和断裂伸长率,当PZT质量分数为4%时,纤维膜具有最佳的综合力学性能,能够满足可穿戴设备的要求。     

原位聚合法制备凝胶型离子液体／PMMA聚合物电解质

采用原位聚合法制备了含有N-甲基、丙基哌啶双三氟甲磺酰亚胺离子液体的凝胶型聚合物电解质．利用SEM和XPS测试了电解质膜与LiFePO4电极的界面状态,充放电循环后,在电解质膜与LiFePO4之间有一层薄膜,这层薄膜中含有N和S元素．结果表明,随着充放电的不断进行,凝胶型电解质中未聚合的甲基丙烯酸甲酯与电极表面的锂离子之间发生电子转移,形成SEI膜,至少要三个循环后才能形成稳定的SEI膜．随着SEI膜的增厚,放电容量增加,阻碍了电子转移,使系统更加的稳定．在不同倍率下测试了凝胶型离子液体／PMMA聚合物电解质电池性能,当充放电达到30个循环时,0．2、0．5和1C下电池比容量分别为132、128和120mAh／g．     

纳米TiO2薄膜光阳极的制备及性能

本文以钛酸正丁酯为前驱物、乙醇作为分散剂、二乙醇胺作为螯合剂、聚乙二醇作为表面活性剂,采用溶胶-凝胶法制备得到一种TiO2溶胶,并通过乙酸或氨水作用后制得另外两种溶胶,分别在室温于ITO导电玻璃上涂制,得到5种单一粒径范围纳米TiO2薄膜和具有两种粒径范围膜层的6种纳米TiO2薄膜;XRD和SEM等测试结果表明,纳米TiO2薄膜为锐钛矿相或锐钛矿与金红石相的混合相,其粒径分布范围在15～30nm,30～50 nm,40～80 nm区间。采用浸渍法将所制备的膜进行染料的敏化,得到染料敏化纳米TiO2薄膜半导体光阳极,测试结果表明,在所制备的纳米TiO2薄膜中,具有两种粒径范围膜层的纳米TiO2薄膜的光电性能相对较好。     

CoFe2O4／TiO2磁性复合薄膜的制备及表征

以钛酸丁酯和金属盐酸盐为原料,采用溶胶-凝胶工艺制备了CoFe2O4／TiO2复合薄膜,分析了不同热处理温度对复合薄膜晶粒生长及薄膜表面形貌的影响．通过XRD射线、拉曼光谱、扫描电子显微镜、偏光显微镜对薄膜热分解中物相变化过程及其表面形貌进行了观测,用振动样品磁强计（VSM）测定了样品的磁性．实验结果表明：溶胶-凝胶法制得的复合薄膜,两相组分晶体各自析出长大,CoFe2O4组分均匀地分布在TiO2基体中,随着热处理温度的升高,薄膜的磁性增强．     

多重网络增强的层状光子晶体水凝胶及应力变色响应

基于PDGI/PAAm (PDGI/SN)层状光子晶体水凝胶,制备了多重网络PDGI/PAAm-PAMPS-PAAm(PDGI/TN)水凝胶,将水凝胶浸入6 : 4(V/V)乙醇水溶液中去溶胀,记为凝胶PDGI/TN-0.6。结果表明,引入多重网络之后,PDGI/TN凝胶的溶胀率从PDGI/SN的850% ± 45%提高到1070% ± 50%,颜色从蓝色(λ_max=450 nm)变为透明,去溶胀后Bragg衍射峰为670 nm,实现凝胶的Bragg衍射峰在450－670 nm间调控。拉伸和压缩实验说明,PDGI/TN-0.6力学性能优异,拉伸强度和压缩强度分别达到0.99和37.0 MPa。同时,PDGI/TN-0.6具有优异应力变色响应性,压缩应变(ε_c)从0增加到0.5,Bragg衍射峰发生蓝移,响应范围覆盖可见光;当撤去应力后,立即恢复初始状态,可重复多次。利用扫描电镜(SEM)进一步研究了层状光子晶体水凝胶层微观结构。     

LaNiO3衬底上Pb(ZrxTi1－x)O3铁电薄膜及梯度薄膜的制备和研究

报道了在镍酸镧 (LaNiO₃, 简称LNO)衬底上锆钛酸铅 [Pb(Zr_xTi_1－x)O₃, 简称PZT]铁电薄膜及其成分梯度薄膜的结构、介电性能、铁电性能以及热释电性能. 首先通过金属有机化合物热分解(MOD)法在Si(100)基片上制备出LaNiO₃, 薄膜, 再通过溶胶-凝胶(sol-gel)法, 在LNO/Si(100)衬底上制备出Pb(Zr_0.80Ti_0.20)O₃, [PZT(80/20)]和Pb(Zr_0.20Ti_0.80)O₃, [PZT(20/80)]铁电薄膜及其成分梯度薄膜. 经俄歇微探针能谱仪(AES)对制备的梯度薄膜进行了成分深度分析, 结果证实成分梯度的存在. 经XRD分析表明, 制备的梯度薄膜为四方结构和三方结构的复合结构, 但其晶面存在一定的结构畸变. 经介电频谱测试表明, 梯度薄膜的介电常数比每个单元的介电常数要大, 但介电损耗相近. 在10 kHz下, 梯度薄膜的介电常数和介电损耗分别为317和0.057. 经电滞回线的测试表明, 梯度薄膜的剩余极化强度比每个单元都大, 而矫顽场却明显较小. 梯度薄膜的剩余极化强度和矫顽场分别为29.96 μC•cm^-2 和54.12 kV•cm^－1. 经热释电性能测试表明, 室温下梯度薄膜的热释电系数为5.54×10-8 C•cm^－2•K^－1, 高于每个单元的热释电系数.     

A Comparison of the Nanostructure of Lead Zirconate,Lead Titanate and Lead Zirconate Titanate Sols

Sol-gel processing has been widely used for the fabrication of lead zirconate titanate (PZT) thin films. To successfully and consistently make high quality thin films for different applications, we must develop a fundamental understanding of the structures of the sols. In this study, the characters of lead titanate (PT) and lead zirconate (PZ)sols were studied by measuring the rheological properties and particle sizes in them and comparing their behaviours. The average particle sizes in unhydrolysed PT, PZ and PZT sols are 11.5, 1.0, and 6.0 nm, respectively. PT sol has the highest rate of hydrolysis. It gels at about 24 h after hydrolysis. PZ and PZT sols have a quite similar feature in hydrolysis. The reasons for the differences in the hydrolysis behaviour of the different types of sol are discussed in terms of a model which indicates that the inhomogeneous sols consist of 5 to 6 nm PT particles surrounded by much smaller PZ particles, which tend to dominate the sol behaviour.     

Effect of sol-gel preparation method on particle morphology in pure and nanocomposite PZT thin films

Double-scale composite lead zirconate titanate Pb(Zr_0.52Ti_0.48)O₃ (PZT) thin films of 360 nm thickness were prepared by a modified composite sol-gel method. PZT films were deposited from both the pure sol and the composite suspension on Pt/Al₂O₃ substrates by the spin-coating method and were sintered at 650°C. The composite suspension formed after ultrasonic mixing of the PZT nanopowder and PZT sol at the powder/sol mass concentration 0.5 g mL⁻¹. PZT nanopowder (≈ 40–70 nm) was prepared using the conventional sol-gel method and calcination at 500°C. Pure PZT sol was prepared by a modified sol-gel method using a propan-1-ol/propane-1,2-diol mixture as a stabilizing solution. X-ray diffraction (XRD) analysis indicated that the thin films possess a single perovskite phase after their sintering at 650°C. The results of scanning electron microscope (SEM), energy-dispersive X-ray (EDX), atomic force microscopy (AFM), and transmission electron microscopy (TEM) analyses confirmed that the roughness of double-scale composite PZT films (≈ 17 nm) was significantly lower than that of PZT films prepared from pure sol (≈ 40 nm). The composite film consisted of nanosized PZT powder uniformly dispersed in the PZT matrix. In the surface micrograph of the film derived from sol, large round perovskite particles (≈ 100 nm) composed of small spherical individual nanoparticles (≈ 60 nm) were observed. The composite PZT film had a higher crystallinity degree and smoother surface morphology with necklace clusters of nanopowder particles in the sol-gel matrix compared to the pure PZT film. Microstructure of the composite PZT film can be characterized by a bimodal particle size distribution containing spherical perovskite particles from added PZT nanopowder and round perovskite particles from the sol-matrix, (≈ 30–50 nm and ≈ 100–120 nm), respectively. Effect of the PZT film preparation method on the morphology of pure and composite PZT thin films deposited on Pt/Al₂O₃ substrates was evaluated.     

Development of nanoscale inhomogeneities during drying of sol-gel derived amorphous lead zirconate titanate precursor thin films

The structural evolution of sol-gel derived lead zirconate titanate (PZT) precursor films during and after physical drying was investigated by transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), selected area electron diffraction (SAED), and time-resolved X-ray diffraction (XRD). Films were deposited from initial 0.3 mol/dm(3) precursor sols with varying hydrolysis ratios. Zr-rich grains of 1-10 nm size, embedded in a Pb-, Zr-, and Ti-containing amorphous matrix were found in as-dried films. The Zr-rich regions were crystalline at hydrolysis ratios [H(2)O]/[PZT] < 27.6, and amorphous at ratios > 100. X-ray diffraction analysis of PZT and zirconia sols revealed that the crystalline nanoparticles in both sols are identical and are probably composed of nanosized zirconium oxoacetate-like clusters. This study demonstrates that time-resolved X-ray diffraction combined with electron energy loss spectroscopy mapping is a powerful tool to monitor the nanoscale structural evolution of sol-gel derived thin films.     

Preparation and Optical Characterization of Sol-Gel Deposited Pb(Zr0.45Ti0.55)O3 Films

Homogeneous crack-free lead zirconate titanate (Pb(Zr_0.45Ti_0.55)O₃: PZT 45/55) films were prepared by a chemically modified sol-gel process using lead acetate trihydrate, zirconium n-propoxide, and titanium isopropoxide precursors. The coating solutions were modified by the addition of diethanolamine. Single and multilayer films were deposited with a 2000 rpm spin rate on fused silica and MgO(100) substrates. Multiple spin coating with an intermediate heat treatment in air at 400°C for 3 min between coatings was performed to obtain films up to 2 m in thickness. The formation of the tetragonal perovskite structure was found to depend on the intermediate firing temperature, final annealing temperature, and annealing time. A 650°C rapid thermal annealing treatment in oxygen was required to crystallize the PZT film into the perovskite structure. The films were characterized using optical spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and thermo-gravimetry and differential scanning calorimetry (TG-DSC). The optical constants of the PZT films were evaluated from spectral transmittance and reflectance measurements. Optical constants are presented over the visible and near infrared region.     

The diffusion of Pt in BST films on Pt/Ti/SiO2/Si substrate by sol-gel method

Barium strontium titanate (Ba_0.65Sr_0.35TiO₃) ferroelectric thin films have been prepared by sol-gel method on Pt/Ti/SiO₂/Si substrate. The X-ray diffraction (XRD) pattern indicated that the films were a polycrystalline perovskite structure and the atomic force microscope (AFM) image showed that the crystallite size and the root mean square roughness (RMS) were 90 nm and 3.6 nm, respectively. The X-ray photoelectron spectrum (XPS) images showed that Pt consisting in BST thin films was the metallic state, and the Auger electron spectroscopy (AES) analysed the Pt concentration in different depth profiles of BST thin films. The result displayed that the Pt diffusion in BST thin film is divided into two regions: near the BST/Pt interface, the diffusion type was volume diffusion, and far from the interface correspondingly, the diffusion type became grain boundary diffusion. In this paper, the previous researcher’s result was used to verify our conclusion.     

电沉积法制备介孔TiO_2/CdS薄膜光电极

采用阴极恒电位沉积法,在介孔TiO2薄膜上制备了介孔TiO2/CdS薄膜光电极,用XRD,SEM,Raman,SPS和UV-Vis等多种手段对薄膜电极进行了表征.结果表明,CdS成功沉积到介孔TiO2的表面和孔道内,形成了异质结结构.通过光电流作用谱考察了该复合体薄膜电极的光电性能,结果表明,与单纯的介孔TiO2薄膜相比,其光电转换效率显著提高,这是由于CdS具有吸收可见光的特性以及CdS与介孔TiO2形成异质结从而使得光生载流子更容易分离的结果.     

掺杂Sb对纳米TiO2薄膜的超亲水性和微结构的影响

用溶胶-凝胶法将纳米TiO2:Sb薄膜沉积在玻璃基板上.研究了掺杂浓度对薄膜的光致超亲水性、薄膜结构和晶相转变的影响.结果表明,纯TiO2薄膜中， TiO2不仅以无定型态存在，而且还以板钛矿和锐钛矿的形式存在.掺杂Sb提高了TiO2由无定型向板钛矿和锐钛矿转变的速率.掺入适量的Sb后， TiO2薄膜表现出更好的光致超亲水性.由XRD谱可算出薄膜的晶粒大小为13.3～20.0 nm.     

Bi1-xFexVO4薄膜光阳极的制备及光电化学性能

采用一步滴涂法在掺氟二氧化锡(FTO)导电玻璃上制备了Bi_1-xFe_xVO₄(x=0, 0.05, 0.10, 0.25, 0.40)薄膜, 表征了其结构、 形貌、 光学以及光电化学方面的性质. 结果表明, 掺入Fe后Bi_1-xFe_xVO₄薄膜的光电流密度与 BiVO₄薄膜相比均有所提高, 其中25% Fe-BiVO₄薄膜表现出最优的光电化学性能. 在0.1 mol/L磷酸缓冲溶液(pH=7.0)中, 1.23 V(vs. RHE)电势下25% Fe-BiVO₄薄膜的光电流密度为0.50 mA/cm², 与BiVO₄薄膜的0.15 mA/cm²相比提高了3倍多. 结合X射线衍射(XRD)、 拉曼光谱(Raman)和X射线光电子能谱(XPS)表征结果证实Fe³⁺以FeVO₄的形式存在于Bi_1-xFe_xVO₄薄膜中, 形成了BiVO₄/FeVO₄复合物薄膜. 紫外-可见光谱(UV-Vis)结果显示, 所有Bi_1-xFe_xVO₄薄膜的禁带宽度均为2.4~2.5 eV. 25% Fe-BiVO₄薄膜光电化学性能的提升主要归因于光生载流子转移效率(η_trans)和分离效率(η_sep)的提高. 能级结构图表明, BiVO₄和FeVO₄之间可以形成Type Ⅱ型能级结构排列, 可以促进光生载流子的分离与转移, 是25% Fe-BiVO₄薄膜光电化学性能提升的内在机理.     

Fabrication of Sol-Gel Optical Waveguide by Hot-Dip Coating Process

The TiO₂: Sb nanoscale thin films were deposited on glass substrates by the sol–gel dip-coating method. The influence of the dopant density on the structure and the phase transformation of the thin films were investigated by X-ray diffraction (XRD) and Raman spectra. From the results of XRD, the thin films were in a majority of anatase state. The results of Raman spectra indicated that the non-doped TiO₂ thin film composed of not only anatase but also brookite phase. Dopant Sb enhances the transformation of the TiO₂ from brookite to anatase phase. After doping proper amount of Sb, the thin films show more superhydrophilicity than the non-doped TiO₂ thin film as well. The crystal size of the TiO₂ : Sb is about 13.3–20 nm calculated from the XRD patterns.     

Ultra light tunable capacitor based on PZT thin film deposited onto aluminium foil

Lead zirconate titanate (PZT) thin films with a Zr/Ti ratio of 57/43, elaborated by a derived sol–gel process, have been deposited onto bare and RuO₂ coated aluminium substrate 16 μm thick. Commercial aluminium foil presents many advantages as ultra light weight (43 g m^?2), conformability, conduction, can be easily cut, and is one of the cheapest substrates used for PZT thin films deposition (<0.1$ m^-2). XRD measurements have shown a well crystallized PZT in the perovskite structure and ferroelectric behaviour has also been observed. By the use of a RuO₂ film 100 nm thick at the PZT/aluminium interface, the coercive field and tunability values have been strongly improved despite an increase of the dielectric losses. The lead excess introduced in the precursor solution has been increased up to 65 % in order to lower the crystallization temperature of the PZT around 560 °C and tunability has been studied as a function of annealing time and temperature.