光致变色防伪油墨的应用及前景

光致变色油墨，又名感光变色油墨、光敏变色油墨、日光变色油墨，是指用光致变色材料加入在连接料中，配其他辅助物质，经过加工处理成为一种适应印刷的胶体。此油墨在室内无色，到室外感应到紫外线后显示颜色。     

水性聚氨酯结构对糠醛基染料变色行为的影响

研究糠醛基染料(FDs)在不同结构水性聚氨酯(WPU)中的变色行为,是进一步推进这类变色材料应用的前提。因此,设计并制备了玻璃化转变温度(T_g)不同的聚醚型WPU(MWPU)及聚酯型WPU(ZWPU),研究FDs在这两种WPU薄膜中的变色行为。研究发现,加入1.5%(质量分数) FDs对WPU薄膜的T_g及热分解性能几乎没有影响。FDs在极性较高的MWPU薄膜中,倾向于形成极性更强的无色环状结构,致使薄膜初始颜色较浅。其次,较高的T_g会使得薄膜颜色恢复速率及恢复程度更低,当温度接近WPU的T_g时,薄膜颜色变化被冻结。最后,通过实验证明FDs-MWPU这款变色材料能作为疫苗安全指示标签,降低人们因注射失效疫苗而造成不适的风险。     

基底温度对NiOx薄膜性质的影响及其电致变色机理研究

摘要采用磁控溅射法在不同基底温度的条件下制备NiOx薄膜。对制备的薄膜采用XRD、SEM、Raman、XPS、可见光分光光度计及循环伏安曲线等测试手段进行对比分析。结果表明，在低温条件下制备的NiOx薄膜比常温沉积的薄膜会提供更多的Ni^2＋离子参与变色反应，同时薄膜中疏松的孔洞有利于离子进出。SEM图中可以看出液氮流量越大，温度越低则晶粒越小，会造成沉积组织明显疏松，这些孔隙非常有利于H^＋的拉入抽出。通过Raman测试发现，低温沉积的薄膜可以提供更多的Ni^2＋空位。XPS测试发现NiOx薄膜在KOH溶液中的变色是由H^＋引起的，反应机理为：Ni（OH）2←→＋NiOOH＋H^＋＋e^-。循环伏安测试发现173K条件下制备的NiOx薄膜（η=38．2cm^2／C，λ=550nm）比室温制备的NiOx薄膜（η=16．3cm^2／c，λ=550m）有更高的着色系数，表现出更好的变色效率。     

壳聚糖/丙烯酰胺光致变色水凝胶的合成及表征

光致变色系统在视觉信息存储,紫外红外光检测等领域应用广泛,但在便携性,响应灵敏度等方面有待提升。本实验以壳聚糖(CS),丙烯酰胺(PAAm)为基体,Fe~(3+)为交联剂,钼酸铵(Mo7)为光致变色介质合成了CS-Fe~(3+)复合水凝胶。实验结果表明,钼酸铵与Fe~(3+)通过配位键引入水凝胶网络中,Fe~(3+)在一定浓度范围内能增强复合水凝胶的光致变色性能,复合水凝胶对紫外光敏感,暴露在紫外光下仅5 min便开始变色。通过控制紫外光照射时间以及水凝胶所处环境温度,可控制水凝胶光致变色程度及褪色速率。在60℃经过75 min CS-Fe■水凝胶即可完全褪色并重复使用。光照时在水凝胶表面覆盖刻有不同图案的掩模,可在水凝胶上记录不同的信息,赋予水凝胶光学存储性能。将光致变色材料引入水凝胶中不仅使光致变色材料实现便携化,同时水凝胶还具有极佳的光学敏感性,能更好地应用于紫外光检测和视觉信息存储中。     

掺杂光致变色材料的涂料光致变色性能的研究

提出一种能用太阳光（或紫外光）调节色彩的涂料制备方法。通过光致变色材料、紫外线吸收剂和涂料的协同作用，当太阳光（或紫外光）照射后，漆膜能自动变色，但在无照射时又能恢复原有颜色。此涂料色彩丰富、图案变化多样，让人感觉更舒适。     

添加剂对水热法制备超细氧化铁的影响

以硫铁矿烧渣酸浸液为原料，采用水热法制备超细氧化铁。添加剂对水热产物的物相影响较小，但对水热产物形貌影响较大。当水热反应温度为190℃、反应时间为30min、总铁浓度为3mol／L、n（Fe^2＋）/n（Fe^3＋）取0．145时，加入添加剂CTAB、NaH2PO4、CO（NH2）2水热反应所得产物为椭球形粒子；加入PVP、OP所得水热产物为球形氧化铁粒子，但其粒径差异较大。酸浸液中n（Fe^2＋）／n（Fe^3＋）物质量之比对水热产物物相和形貌有重要影响。当n（Fe^2＋）/n（Fe^3＋）为0时，水热产物为大小均匀的球形超细Fe2O3粒子，其粒径约为0.11μm；当n（Fe^2＋）／n（Fe^3＋）为0．145时，其水热产物颗粒增大、粒径各异，物相为Fe2O3、Fe3O4；当n（Fe^2＋）/n（Fe^3＋）为0.842时，从放大3万倍SEM照片，难以观测其形貌与粒径大小，其物相为Fe3O4。     

聚多巴胺对氧化钨膜电致变色性能的影响探究

通过恒定电压电化学沉积的方法在氧化铟锡(ITO)玻璃表面制备了氧化钨(WO_3)与聚多巴胺(PDA)复合膜材料,研究了电解液中加入不同体积PDA对复合膜材料电致变色性能的影响。采用红外光谱仪(FT-IR),原子力显微镜(AFM),X射线光电子能谱(XPS),循环伏安(CV)等测试手段对复合膜材料的结构和性能进行了表征;将电化学工作站和紫外-可见吸收光谱联用,在-1.0～+0.8 V的电压范围内,对不同PDA添加量的复合膜材料的电致变色性能进行研究。研究结果表明,25 mL过钨酸电解液中含1.17μg/mL PDA时所制备的复合膜材料性能较为理想,透过率变化为77%,着色时间为7.0 s,褪色时间为5.5 s,运行1200周期后透过率变化为第1周期的80%,循环稳定性好,实现了从无色到蓝色,再恢复为无色的可逆颜色变化,可以作为将自修复性能引入WO_3电致变色复合膜的途径进行下一步研究。     

Pt／WO3纳米薄膜的氢敏特性

用溶胶-凝胶法和磁控溅射法相结合制备了催化剂Pt掺杂的WO3纳米薄膜,通过改变氢气的体积分数、催化剂Pt的含量及热处理温度等实验因素,对Pt／WO3薄膜的氢致变色性能进行了测试;并利用X射线光电子能谱仪（XPS）分析了薄膜的氢敏机理。实验结果表明：先用溶胶-凝胶法制得WO3薄膜,然后再用磁控溅射法在该WO3薄膜上溅射掺杂5％的Pt,制得Pt／WO3双层纳米薄膜,经100℃热处理后,可以获得性能稳定且具有良好氢敏特性的优质薄膜;薄膜能检测的氢气浓度低至0．008％;XPS分析表明,W^5＋与W^6＋之间的转换是引起WO3薄膜氢致变色现象的主要原因。     

真空蒸发沉积18烷基取代螺吡喃薄膜的光致变色及光电子谱研究

利用真空蒸发的方法在玻璃载片上沉积了 18烷基取代螺吡喃薄膜 ,并利用光吸收谱和光电子谱研究了薄膜的光致变色特性及变色前后分子结构的变化情况。实验结果发现 ,真空蒸发沉积的 18烷基取代螺吡喃薄膜具有良好的光致变色性能 ,在紫外光的照射下可以发生明显的光致变色反映。光电子谱分析 :经紫外线照射后 ,N1s、O1s光电子峰发生明显的变化 ,说明经紫外线照射后分子结构发生了变化 ,导致分子内部电荷的重新分布。另外紫外线照射后氧含量增加 ,这是因为紫外线照射后薄膜表面对水汽的吸附能力增加所致     

WO3薄膜制备及其电致变色性能研究

采用直流反应磁控溅射方法在室温下制备WO3薄膜。研究溅射功率对WO3薄膜结构及电致变色性能的影响规律,考察退火后WO3薄膜的结构演变及电致变色性能变化。结果表明溅射功率为270W时薄膜表现出较好的电致变色性能,其调制幅度达78.5%,着色时间为9s,褪色时间为3.2s。将该功率下制备的WO3薄膜进行退火处理,其结构由非晶态转变为晶态,但调制幅度、响应时间特性都发生一定程度的退化。非晶态WO3薄膜相比晶态结构具有更快的响应时间和更宽的调制幅度,但晶态薄膜具有更好的循环稳定性。     

预测相融共混膜氧气透过率的分形渝渗模型

目的 预测相融体系共混膜氧气透过率,为高阻氧共混膜的生产和设计提供理论依据.方法 应用分形与渝渗理论提出一种氧气透过率预测模型,该模型能够在高阻氧材料体积分数条件下更准确地估算相融体系共混膜的氧气透过率.以聚酯/聚萘二甲酸乙二醇酯(PET/PEN)共混膜为例,通过扫描电镜分析共混膜微观形貌,确定PET/PEN共混膜中氧气渗透维数,并根据渗透维数结合文中提出的预测模型计算PET/PEN共混膜氧气透过率,最后通过实验数据验证该模型的有效性.结果 氧气在PET/PEN混合膜中的渗透可以简化为二维渗透.在低PEN体积分数条件下,现有模型和文中提出的预测模型均与实验结果高度吻合.该模型在高PEN体积分数条件下展现出了现有其他模型所没有的曲线趋势,能够更准确地描述高阻氧材料在共混膜体系中对氧气的阻隔作用.结论 文中提出的预测模型能够用于预测相融体系共混膜的氧气透过率.     

A Review and Evaluation of Prediction Models of Gas Permeation for a Blended Flexible Packaging Film

Barrier properties of blended film, such as oxygen permeability, are a collective behaviour contributed by different resins. This study reviews 10 most widely used prediction models of gas permeation for two‐phase blended film along with their assumptions and the interconnection and similarities between these models. Two blended blown films, LDPE/EVOH and PET/PEN, were produced representing two different permeability ratios of matrix‐to‐disperse phase. Effective oxygen permeability of the blended films was predicted by the models and compared with measured values. Scanning electron microscopy (SEM) micrographs of both films were obtained to understand the morphology in relation to gas permeation. The Fricke model and the effective medium theory model are recommended in this study to predict effective permeability of a blended flexible packaging film. Copyright © 2016 John Wiley & Sons, Ltd.     

Formulation and characterization of chitosan-based hydrogel films having both temperature and pH sensitivity

Chitosan-based hydrogel films having both temperature and pH sensitivity were prepared by blending chitosan with temperature sensitive poly (N-isopropylacrylamide) (PNIPAAm) and polyethylene glycol (PEG, Mw 2000). PEG was added to enhance film properties, such as thermal, mechanical and swelling properties. Differential scanning calorimetry (DSC) study indicated that the physically blended films exhibited a lower critical solution temperature (LCST) identical to that of pure PNIPAAm (around 32 °C). FT-IR data indicated that the temperature sensitivity is due to the PNIPAAm component in the film. The thermal analysis showed that chitosan and PNIPAAm were compatible and the blended films are apt to crystallize. The X-ray diffraction study further showed that the blended films had a higher crystallinity level than chitosan or PNIPAAm alone. The newly formed crystalline domains acted as physical crosslinkers and greatly increased the crosslinking level of the blended films, which, in turn, affected the swelling behavior and mechanical property of the blended films. Scanning electron microscopy (SEM) revealed that the blended swollen films exhibited a more porous structure at 37 °C (>LCST) than at room temperature (<LCST), though their swelling ratios were reduced as temperature increased from room temperature to 37 °C because of the dehydration nature of PNIPAAm at temperatures above its LCST. The results demonstrated that physically blended temperature sensitive films could be formulated, which are capable of producing more pores upon heating. The blended films were also found to be pH sensitive due to the fact that chitosan, one of the film components, has many pendant amino groups.     

Further investigations on a poly(vinyl alcohol)- polyelectrolyte chemically selective optical film

The ionomer poly(vinylbenzyltrimethylammonium chloride) has been blended with cross-linked poly(vinyl alcohol) to form optically clear composites that can be covalently linked as thin films to oxide surfaces. Films are characterized using spectroscopic ellipsometry with refractive index (n) and extinction coefficient (k) data presented for wavelengths 300 to 1100 nm. A refractive index of 1.54 and average thickness of 709 nm are typical of an air dry film prepared by spin-coating. Dynamic in situ ellipsometry results for films exposed to 0.1 M KNO(3) and 1.0 mM Fe(CN)(6)(-3) are presented. Upon initial exposure to 0.1 M KNO(3), an air dry film expands by about 160% and stabilizes in size and refractive index at about 18 hours. Ion exchange of film cationic groups with ferricyanide is marked by slight film contraction, presumably due to electrostatic cross-linking by the multivalent anion. These films are useful in the spectroelectrochemical sensor with our newly developed fluorescence detection mode, as demonstrated by results of the reversible incorporation of the fluorescent anion fluorescein.     

氟树脂改性漆酚复合涂料的老化性能研究

采用氟树脂对漆酚进行改性,对改性后漆酚涂膜进行了自然老化和人工加速老化测试。通过傅立叶红外光谱(FTIR)、紫外光谱(UV)及扫描电镜(SEM)等手段对老化后的样品进行表征。结果表明,氟树脂含量在30%～90%(wt)时改性样品经过人工加速老化试验后表面出现破坏的时间大于漆酚涂膜,且经模拟太阳光照射120h后,失光率较小;暴露在自然环境中2880h后,表面仍未出现破坏现象。而漆酚涂膜在自然环境中暴露2544h后,表面已被破坏。研究表明,改性漆酚涂膜的耐老化性能较漆酚涂膜有大幅提高。     

Preparation and Photochromic Properties of Hybrid Thin Films Based on Heteropolyoxometallate and Polyacrylamide

A series of photochromic hybrid films were prepared through entrapping Dawson type tungsten heteropolyoxomet-allates(P2W18O62^6-) and molybdenum heteropolyoxometallate(P2Mo18O62^6-) into polyacrylamide matrix.FTIR results showed that the Dawson geometry of heteropolyoxometallates in still preserved inside the composites and strong coulombic interaction is built between heteropolyoxometallates and polyacrylamide via hydrogen bonding.Ir radiated with ultraviolet light ,the transparent films change from colorless to blue and show reversible photochromism.The bleaching process occurs when the films are in contact with air or O2 in the dark.The molybdenum heteropolyoxometallate hybrid film has higher photochromic efficiency and slower bleaching reaction than tungsten heteropolyoxometallate hybrid film.ESR results indicated that polyacrylamide is a hydrogen donor and the photoreduced process is in accordance with the radical mechanism.     

Preparation and photochromic behavior of crosslinked polymer thin films containing polyoxometalates

A series of reversible photochromic nanocomposite films were prepared by entrapping phosphotungstic acid (PWA) and molybdenumphsophoric acid (PMoA) into P(VP-BVA), which was a crosslinked polymer based on N-vinylpyrrolidone (VP) and bisvinyl-A (BVA). The microstructure, photochromic behavior and mechanism of the films were studied with transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectra (UV-vis) and electron resonance spectra (ESR). The TEM image showed that the polyoxometalates particles had regular microstructure with narrow size distribution (average diameter of 30 nm) in hybrid films. FT-IR results showed that the Keggin geometry of polyoxometalates (POM) was still preserved inside the composites and strong coulombic interaction between POM and crosslinked polymer matrix was built. Irradiated with ultraviolet light, the transparent films changed from colorless to blue and showed reversible photochromism. Oxygen plays an important role during the bleaching process. PMoA/P(VP-BVA) film had higher photochromic efficiency and slower bleaching reaction than PWA/P(VP-BVA) film. The characteristic signals of W (V) or Mo (V) in ESR spectra indicated that electron transfer occurred between the organic substrates and heteropolyanions under UV irradiation, which induced heteropolyanions to heteropolybules with simultaneous oxidation of the organic substrates.     

壳聚糖复合保鲜膜制备及其拉伸性能研究

将充分溶胀的壳聚糖与三偏磷酸钠交联并与硅溶胶共混,制备出了壳聚糖复合保鲜膜,用万能拉力机测试了其拉伸性能。研究结果表明,交联和共混明显提高了壳聚糖复合保鲜膜的力学性能,并且壳聚糖浓度在1.2×10-4～1.4×10-4 mol/L,三偏磷酸钠的含量在0.08%,mSiO2∶m壳聚糖约为0.15时,保鲜膜综合力学性能最佳。     

Preparation and properties of electrochromic iridium oxide thin film by sol-gel process

We established a method for preparation of iridium oxide thin film by the sol-gel dip-coating process where iridium chloride was used as a starting material. The coating solution was prepared by reacting iridium chloride, ethanol and acetic acid. Iridium oxide coating was formed at 2.0 cm/min withdrawing rate. The coating films heat treated at 300°C did not contain impurities. Iridium oxide crystallized at temperatures above 450°C. Both crystalline and amorphous iridium oxide thin films showed electrochromism. The change in transmittance of the crystalline Ir₂O₃ film is larger than that of the amorphous Ir₂O₃ under the same experimental conditions. The transmittance of the crystalline thin film (film thickness 200 nm, measured at 400 nm) decreased 13.0% on application of 3 V for 1 s.     

掠射角溅射沉积纳米结构氧化钨薄膜

采用掠射角反应磁控溅射法在室温下沉积了纳米结构氧化钨(WO₃)薄膜, 并对薄膜进行热处理。利用场发射扫描电镜(FE-SEM)和X射线衍射仪(XRD)对氧化钨薄膜的形貌和结构进行了表征。当掠射角度为80°时, 采用直流电源沉积的氧化钨薄膜具有纳米斜柱状结构, 而采用脉冲直流电源沉积的薄膜呈现纳米孔结构。纳米薄膜经450℃热处理3 h后, 纳米斜柱彼此连接, 失去规整结构, 而纳米孔结构的孔尺寸变大。XRD分析表明室温沉积的氧化钨薄膜具有无定形结构, 经450℃热处理1 h后, 转变为单斜晶相。具有纳米斜柱状或纳米孔结构氧化钨薄膜的光学调制幅度在波长600 nm时达到60%, 且电致变色性能可逆。