玻璃用WO3基电致变色材料的研究

电致变色玻璃是电致变色材料最典型的应用,WO_3是一种发现得较早、研究较为深入、应用最为广泛的阴极电致变色材料,本文介绍了电致变色材料的分类,并从WO3基电致变色薄膜和WO_3薄膜的制备两个方面对WO3基电致变色材料进行了研究。     

全固态电致变色智能窗

介绍了智能窗的分类及各自的特点,重点研究电致变色智能窗,着重分析了目前国内少见的全固态电致变色智能窗,提出了该智能窗的复合膜层结构,根据全固态的特点,研究了Li Ta O电解质薄膜XRD及SEM图谱,并对不同厚度的电3解质薄膜复合后的智能窗进行了着色-褪色调整范围进行了测试,表明随着电解质薄膜的厚度增加,可增宽智能窗的可见光透过率调整范围。     

工艺参数对磁控溅射WO_3薄膜电致变色性能的影响

本文采用磁控溅射法制备了用于电致变色器件的WO_3薄膜,用X射线衍射仪(XRD)、场发射扫描电镜(FE-SEM)、紫外-可见分光光度计(UV-Vis)对其物相组成、微观形貌以及电致变色性能进行了表征。结果表明:在溅射压强为2 Pa、氩氧比为60:20时所制备的WO_3薄膜厚度适中,且有利于离子的嵌入/脱出,而以此薄膜制备的电致变色器件光调制范围最大,褪色时间最短,着色效率达82.9 cm~2/C。     

乙醇胺强化解离WO_(3)·H_(2)O微米片制备柔性WOx电致变色器件EI北大核心CSCD

WO_(3)电致变色器件具有变色响应时间短、光学对比度高等优点,在汽车后视镜、智能窗等领域具有重要应用。近年来,随着可穿戴电子设备的迅速发展,柔性WO_(3)薄膜的制备成为柔性电致变色器件领域的研究热点。但WO_(3)结晶温度较高,而受聚合物衬底可耐受温度的限制,通常需要采用磁控溅射、电子束蒸镀等真空气相沉积技术制备晶态柔性WO_(3)薄膜。此技术对设备要求高,且所制备的薄膜结构较致密,不利于电解液的渗透和电解质离子的快速脱嵌。采用液相回流化学法预合成了结晶态WO_(3)·H_(2)O微米片粉体,首次采用乙醇胺等胺类分子使WO_(3)·H_(2)O强化解离为高度分散的纳米粒子胶体溶液,经旋转涂覆液相成膜技术制备成柔性晶态WO_(x)薄膜并应用于柔性电致变色器件。机理研究表明,胺基官能团与WO_(3)·H_(2)O微米片的强界面相互作用产生的电荷斥力使其迅速解离。所制备的柔性WO_(x)电致变色器件的着色和褪色时间分别为5.9 s和5.4 s,着色效率最高可达146.7 cm^(2)/C,经200次弯折后仍具有较好的性能。     

不同工艺对PANI/PAA复合薄膜的电致变色性能影响研究

采用直接聚合法与逐层镀膜法分别成功制备了聚苯胺(PANI)/聚丙烯酸(PAA)复合薄膜,通过扫描电镜(SEM)、傅里叶变换红外光谱(FT-IR)等方法考察了两种工艺制备的薄膜的形貌和微结构,并测定了两种复合薄膜的循环伏安性能(CV)、电流响应特性(CA)及电致变色性能。结果表明,SEM与FT-IR证实了两种方法制备的PANI/PAA复合薄膜仅在材料结构上有所不同;直接聚合法制备的PANI/PAA复合薄膜(PANI/PAA-DP)表面具有较大颗粒,2对明显的氧化还原峰,氧化态和还原态的响应时间分别为120ms和226ms,在600~700nm波长处的透过率调制幅度为10%;逐层镀膜法制备的PANI/PAA复合薄膜(PANI/PAA-LP)具有多孔的网络结构,3对氧化还原峰,氧化还原反应更明显,电致变色性能更优异,其氧化态和还原态的响应时间分别为45ms和67ms,在600~700nm波长处的透过率调制幅度可达40%。     

添加聚乙烯醇改善三氧化钨电致变色薄膜性能的研究

为改善三氧化钨薄膜的电致变色性能,采用钨粉过氧化聚钨酸溶胶-凝胶法制备了添加聚乙烯醇的三氧化钨电致变色薄膜.采用扫描电镜、紫外可见分光光度计和CHI电化学工作站分别测定和分析了三氧化钨薄膜的微观结构、光透过性能和循环伏安特性.结果表明,添加一定量的聚乙烯醇可使薄膜的结构更加平整,变色更为均匀;在着色态、褪色态下的光透过率之差达到60%以上,变色可调范围变大.电致变色可逆性能和光谱性能较不添加聚乙烯醇有所提高.     

溅射总压对氧化钒薄膜的结构及电致变色性质的影响

采用高频磁控溅射工艺制备了两种不同性能的V2O5薄膜,并研究了溅射总压对其微观结构、循环伏安特性及电致变色特性的影响。结果表明：当功率一定（3．8W·cm^-2)时,在高气压沉积的V2O5薄膜中出现了微晶相,而在低气压沉积的薄膜中为非晶相。从循环伏安过程中实时记录的透过率变化曲线可见：随着Li^ 离子和电子的双重注入,薄膜在某一波长处的透过率前一阶段是增加或降低,而后一阶段却相反。含微晶相的薄膜上述现象更为明显,而且其储存Li^ 离子的容量也要大许多。应用能带结构理论定性地解释了V2O5薄膜复杂的电致变色现象。     

不同工艺对PANI/PAA复合薄膜的电致变色性能影响

采用直接聚合法与逐层镀膜法分别成功制备了聚苯胺(PANI)/聚丙烯酸(PAA)复合薄膜,通过SEM、FTIR考察了两种工艺制备的薄膜的形貌和微结构,并测定了两种复合薄膜的循环伏安性能(CV)、电流响应特性(CA)及电致变色性能。结果表明,SEM与FTIR证实了两种方法制备的PANI/PAA复合薄膜仅在材料结构上有所不同;直接聚合法制备的PANI/PAA复合薄膜(PANI/PAA-DP)表面具有较大颗粒,两对明显的氧化还原峰,氧化态和还原态的响应时间分别为120 ms和226 ms,在600～700 nm波长处的透过率调制幅度为10%;逐层镀膜法制备的PANI/PAA复合薄膜(PANI/PAA-LP)具有多孔的网络结构,3对氧化还原峰,氧化还原反应更明显,电致变色性能更优异,其氧化态和还原态的响应时间分别为45 ms和67 ms,在600～700 nm波长处的透过率调制幅度可达40%。     

基于PEGMA的新型透明凝胶聚合物电解质的制备及在电致变色器件中的应用

以聚乙二醇甲醚甲基丙烯酸酯(PEGMA)、2-羟基-2-甲基苯丙酮(HMPP)和高氯酸锂(LiClO4)为原料,通过固液研磨和紫外固化的方式制备了基于PEGMA的新型透明凝胶聚合物电解质。通过一系列测试,对凝胶电解质的性能及其应用的电致变色器件性能进行了表征。结果表明,制备的凝胶电解质的可见光透过率达97%,热分解温度为250℃,室温下离子电导率为2. 56×10~(-4)S/cm以及应用的电致变色器件在660 nm处光学调制幅度达66. 97个百分点。     

PB/ITO-PET柔性电致变色薄膜制备及性能研究

柔性电致变色器件具有体积小、重量轻、可弯曲等优点,在可穿戴设备、曲面显示器、节能及自适应伪装等领域具有潜在应用前景。本工作以铁氰化钾、氯化钾、无水氯化铁为原料,采用电沉积方法在ITO-PET柔性基底上沉积普鲁士蓝(PB)制得PB/ITO-PET电致变色薄膜,并利用扫描电子显微镜、紫外光谱仪、电化学工作站对PB/ITO-PET电致变色薄膜微观结构和电化学性能进行分析表征。结果表明,电沉积时间为200 s时得到的PB/ITO-PET电致变色薄膜在700 nm波长处光吸收率达到0.755,且PB/ITO-PET电致变色薄膜可在较低电压(0.6 V/-0.3 V)下实现着色和褪色。其光调制范围为68%,着色/褪色响应时间分别为9 s/8 s,着色效率为108 cm2/C。PB/ITO-PET电致变色薄膜经1000次着色-褪色循环后光调制范围为68%,着色效率为100.3 cm2/C。PB/ITO-PET电致变色薄膜500次弯曲,着色效率为105.5 cm2/C,并经1000次着色-褪色循环后着色效率为91 cm2/C,光调制范围为65%。利用ITO-PET为离子存储层(对电极)、凝胶电解质和PB/ITO-PET为工作电极组装得到柔性电致变色器件,其光调制范围为53%,着色/褪色响应时间分别为13 s/18 s。     

A temperature-responsive polyurethane film with reversible visible light transmittance change and constant low UV light transmittance

We prepared a temperature-responsive polyurethane (PU) film with reversible visible light transmittance change, which was opaque at room temperature and became transparent when the temperature rised. The PU film has very low visible light transmittance of 1.4% at room temperature. At 45 °C, the PU film has relatively high transmittance of 66.7% looking translucent. When the temperature goes to 50 °C or above, the transmittance is more than 80% and the PU film is transparent. The reason for this interesting phenomenon about visible light transmittance change was illustrated by polarizing optical microscope and differential scanning calorimetry. While ultraviolet light transmittance of the PU film is very low at all time. Moreover, this PU film has excellent mechanical performance in a wide temperature range. We suppose this PU film has potential applications in many fields such as tunable optical devices or coating materials with smart temperature responsivity. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47140.     

Optical and electrical properties of ITO film on flexible fluorphlogopite substrate

Indium Tin Oxide (ITO) films were prepared, at room temperature, on a fluorphlogopite substrate using magnetron sputtering technology. At various temperatures of 500 °C, 600 °C, 700 °C, 800 °C, and 900 °C, the samples were (had) annealed for 2 h (a 2-h duration). The results showed improvement in the crystalline performance of ITO film at selected annealing temperatures, with a significant reduction in resistivity at 800 °C. The lowest resistivity is 4.08 × 10^?4 Ω-cm, which is nearly an order of magnitude lower than the unannealed sample. All samples have an average light transmittance above 85% in the visible light range (400–800 nm), and with increasing annealing temperature, the average light transmittance tends to decrease. Besides, at the sensitive wavelength of 550 nm, the light transmittance is as high as 93.74%. The sheet resistance testing of the sample was through the number of bending times, which revealed that with the increase of the number of bending, the sheet resistance increases. However, after 1200 bending times, the change rate of the sheet resistance remains below 5%. Thus, the ITO film prepared on the flexible fluorphlogopite substrate revealed excellent optical and electrical properties, good flexibility, and improved stability after high-temperature annealing, which guarantees successful application in flexible electronic devices.     

A thermoplastic polyurethane/rare earth composite film with adjustable fluorescence colors and optimal low-temperature flexibility

In this study, a unique series of luminous polymeric rare earth (RE) composite films was produced by loading RE ions into thermoplastic polyurethane (TPU) using solution blending. Compared to RE ions, luminous polymeric RE composites had greater luminescence intensity, indicating that the introduction of polymer polyurethane as the polymer matrix was advantageous for the luminescence intensity and efficiency of RE ions, with the polymer matrix's absorbed energy being transferred to the RE ions. Furthermore, the findings of the optical transmittance, UV–visible absorption and fluorescence emission spectra suggest that TPU-RE composite films possess exceptional fluorescence luminescence properties and optical transparency. Surprisingly, the fluorescence colors of TPU-RE fluorescent films could be adjusted between red and green by varying the ratios of Eu³⁺ and Tb³⁺ in the films and can be any mixture of red and green hues. In addition, the temperature at 5% weight loss (T_5%) for the TPU-RE composite film composition reached 250 °C. In addition, pure TPU and all TPU-RE hybrid films demonstrated a glass transition temperature (T_g) of about −30 °C. Simultaneously, the tensile strength of the TPU-T₀E₁₀ film reached its maximum (43.6 MPa). Consequently, the TPU-RE composite films will be utilized as photoluminescent functional materials. © 2022 Society of Industrial Chemistry.     

Electrochromic Nb-doped WO3 films: Effects of post annealing

The Nb-doped WO₃ films were deposited by e-beam co-evaporation method using ceramic WO₃ targets and metal Nb slugs. The films were analyzed by glancing incident angle X-ray diffraction (GIAXRD), UV/visible spectrophotometer, electrochemical cyclic voltammetry, X-ray photoelectron spectroscopy (XPS). The as-prepared film is brown and amorphous in structure. The film has low transmission in optical visible region. The XPS results indicate that the as-deposited film is non-stoichiometric. By applying a negative potential, the as-deposited film does not show obvious electrochromic effect. However, the electrochromic properties of Nb-doped WO₃ films are improved by post annealing treatment at 350, 400, and 450 °C in oxygen atmosphere. The Nb-doped WO₃ films transform into crystalline structure and become transparent after post annealing treatment. The energy band gap, optical modulation, and color efficiency increase with annealing temperature.     

Low‐Temperature Deposition of Hexagonal Boron Nitride via Sequential Injection of Triethylboron and N2/H2 Plasma

Hexagonal boron nitride (hBN) thin films were deposited on silicon and quartz substrates using sequential exposures of triethylboron and N₂/H₂ plasma in a hollow‐cathode plasma‐assisted atomic layer deposition reactor at low temperatures (≤450°C). A non‐saturating film deposition rate was observed for substrate temperatures above 250°C. BN films were characterized for their chemical composition, crystallinity, surface morphology, and optical properties. X‐ray photoelectron spectroscopy (XPS) depicted the peaks of boron, nitrogen, carbon, and oxygen at the film surface. B 1s and N 1s high‐resolution XPS spectra confirmed the presence of BN with peaks located at 190.8 and 398.3 eV, respectively. As deposited films were polycrystalline, single‐phase hBN irrespective of the deposition temperature. Absorption spectra exhibited an optical band edge at ~5.25 eV and an optical transmittance greater than 90% in the visible region of the spectrum. Refractive index of the hBN film deposited at 450°C was 1.60 at 550 nm, which increased to 1.64 after postdeposition annealing at 800°C for 30 min. These results represent the first demonstration of hBN deposition using low‐temperature hollow‐cathode plasma‐assisted sequential deposition technique.     

Synthesis and characterization of organosoluble polyfluorinated polyimides derived from 3,3′,5,5′‐tetrafluoro‐4,4′‐diaminodiphenylmethane and various aromatic dianhydrides

A polyfluorinated aromatic diamine, 3,3′, 5,5′‐tetrafluoro‐4,4′‐diaminodiphenylmethane (TFDAM), was synthesized and characterized. A series of polyimides, PI‐1–PI‐4, were prepared by reacting the diamine with four aromatic dianhydrides via a one‐step high‐temperature polycondensation procedure. The obtained polyimide resin had moderate inherent viscosity (0.56–0.68 dL/g) and excellent solubility in common organic solvents. The polyimide films exhibited good thermal stability, with an initial thermal decomposition temperature of 555°C–621°C, a 10% weight loss temperature of 560°C–636°C, and a glass‐transition temperature of 280°C–326°C. Flexible and tough polyimide films showed good tensile properties, with tensile strength of 121–138 MPa, elongation at break of 9%–12%, and tensile modulus of 2.2–2.9 GPa. The polyimide films were good dielectric materials, and surface and volume resistance were on the order of a magnitude of 10¹⁴ and 10¹⁵ Ω cm, respectively. The dielectric constant of the films was below 3.0 at 1 MHz. The polyfluorinated films showed good transparency in the visible‐light region, with a cutoff wavelength as low as 302 nm and transmittance higher than 70% at 450 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1442–1449, 2007     

Preparation of super‐hydrophobic film with fluorinated‐copolymer

Organic superhydrophobic films were prepared by utilizing TA‐N fluoroalkylate (TAN) and methyl methacrylate (MMA) copolymer as water‐repellent materials and inorganic silica powder as surface roughness material has been developed. Coating solutions prepared by adding silica powders into copolymer solution directly (one‐step method) and by adding silica powders into monomers and allowing them to react (two‐step method). The results showed that contact angles of the films prepared by one‐step method (37.6 wt % of silica powders in the coating solution) were greater than 150°, but the transmittance of the film at visible light was only 30%. On the other hand, the contact angle of films prepared by two‐step method (20 wt % of silica powders in the coating solution) was greater than 160° and the transmittance of the film was greater than 90%. The contact angle of the film prepared by poly(octyl acrylate), POA, was 32.1°, but while introducing silica powder into the system, the contact angle of the film was reduced to be smaller than 5°. Thus, superhydrophobic and superhydrophilic films can be obtained by introducing a roughening material on the hydrophobic surface and the hydrophilic surface, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1646–1653, 2007     

电致变色器件中聚丙烯酸酯类电解质的研究

利用分光光度计研究了不同的复合改性丙烯酸酯(紫外固化胶)的雾度和透光率等性质,确定了可适用于电致变色器件的聚丙烯酸酯类电解质基体。用电化学工作站测试恒定含量增塑剂条件下不同LiClO_4含量的聚丙烯酸酯类电解质的离子电导率,以此确定电解质的最佳配比参数。利用磁控溅射技术制备氧化钨和氧化镍薄膜导电玻璃,和电解质组装成电致变色器件(ECD),并测试了不同配比的电解质在相同电压下的变色时间、循环稳定性以及透光率变化等性质。结果表明,LiClO_4∶增塑剂碳酸丙烯酯∶紫外固化胶UV63.07(质量比)为0.246 3∶0.595 2∶2.008 9时,常温下聚丙烯酸酯类电解质的最大离子电导率可达9.06×10~(–4) S/cm。在100次着褪色循环后,光密度变化为0.392 7,可见光范围内的平均透光率变化为29.4%,且具有较好的稳定性,表现出优异的实际应用性能。