基于微流控芯片技术的小尺寸微米级液滴制备

利用微流控芯片技术制备的皮升级微量液滴,作为独立的微反应器,由于其比表面大,高通量等优势,在生物、医学、化学、物理等领域得到了广泛应用。本工作利用软光刻技术制备流聚焦型微流控芯片,研究了微流控芯片中连续相和分散相的流速对微量液滴尺寸的影响。结果显示,增加连续相流速时,微量液滴的尺寸减小;而加快分散相流速时,微量液滴的尺寸增大。当微流控芯片的通道尺寸固定后,由于分散相和连续相的界面张力不变,通过改变连续相和分散相的流速,微量液滴的尺寸范围有限,本工作中微量液滴的尺寸为几百微米至25μm。本工作探究了微流控芯片中如何制备尺寸小于25μm的微量液滴的方法。通过添加活性剂,改变连续相和分散相的界面张力,可实现制备尺寸为10μm的微量液滴。本工作所利用的微量液滴制备方法,制备的10μm大小液滴具备更高的比表面积,反应活性将会更大、在药物释放,颜色显示等领域将有广阔应用前景。     

ITO玻璃电致化学发光微流控芯片的低温键合

研究了一种利用商品化的氧化铟锡ITO）玻璃制作一次性电致化学发光微流控芯片的方法．采用光刻和湿法腐蚀ITO（氧化铟锡）层制作微电极;利用同样的方法,在另一片Cr板玻璃上湿法腐蚀微沟道．在玻璃之间夹入PE薄膜作为间质实现芯片的低温键合,采用开孔和预压处理PE薄膜,解决了键合气泡和储液池边缘变形问题．该方法解决了ITO玻璃不耐高温的问题,在120～125℃实现了微通道的有效封接,芯片的键合强度达到0．7MPa．     

纳米粒子改性聚甲基丙烯酸甲酯的制备及应用

本文主要论述了用纳米粒子SiO2 、TiO2 及石墨、蒙脱土等改性PMMA的方法以及表征手段和材料的用途及展望 ,纳米改性PMMA赋予PMMA很好力学、光学及导电性能。     

PDMS/PVDF优先透有机物渗透汽化复合膜的制备

以商品化聚偏氟乙烯(PVDF)中空纤维超滤膜为基膜,聚二甲基硅氧烷(PDMS)为涂膜材料制备PDMS/PVDF优先透有机物渗透汽化复合膜。用扫描电子显微镜(SEM)对膜结构进行表征,并研究了涂敷方法、基膜热处理工艺、PDMS浓度、固化温度及固化时间等因素对复合膜渗透汽化性能的影响。实验结果表明:基膜120℃下热处理,用10%的PDMS溶液,采用浸涂加真空涂敷的方法涂膜,110℃下交联固化6h制备的复合膜性能最佳。该复合膜在60℃时,分离5%的乙醇水溶液,分离因子可达到21.35,通量为331.21g/(m2·h)。     

基于PDMS金属可调谐光栅的制备工艺研究

分别利用直接法和间接法,制备了基于PDMS(聚二甲基硅氧烷)基底的金属可调谐光栅。由于在金属举离过程中PDMS遇丙酮溶液溶胀,导致直接法在机械调谐过程中光栅严重断裂,而利用间接法可以克服此问题。利用PDMS高弹性的特点,通过控制PDMS的纵、横向拉伸程度,对光栅周期进行连续、任意调谐,可获得预定的目标周期。     

PDMS氧等离子体长效活性表面处理及与Si的键合

为了实现室温、常压下聚二甲基硅氧烷(PDMS)与硅的键合,本文利用氧等离子体分别对PDMS、硅进行表面改性处理.考察了等离子体射频电源功率、处理时间、氧气流量对PDMS-硅键合强度的影响.通过优化工艺适当降低PDMS表面被氧化的程度,可使PDMS活性表面的持续时间延长至45分钟,实现了PDMS-硅在室温常压下的永久性键合.通过X-射线光电子能谱(XPS)对改性后PDMS表面化学组分变化的分析,可推断出PDMS表面Si-OH的稳定性是影响键合强度的主要因素.     

添加β-CD剂的PVDF/MMA共混超滤膜制备及性能研究

以聚甲基丙烯酸甲酯(PMMA)作为第二种聚合物成分与聚偏氟乙烯(PVDF)共混,并添加β-环糊精(β-CD)至铸膜液中,采用L-S相转化法制膜;通过对膜水通量、截留率和强度等的分析,讨论了不同β-CD添加量对膜性能的影响.实验结果表明:该共混体系为部分相容体系;β-CD的添加改善了膜的性能,提高了膜的水通量和截留率等,而且当β-CD的添加量为5%时膜的性能最优;研究对芳香类化合物的去除效果,结果表明添加β-CD的膜比不含β-CD的基膜对多环芳烃(PAHs)有更高的去除率.     

聚甲基丙烯酸甲酯基网络稳定铁电液晶的制备及性能

通过热引发聚合制备了聚甲基丙烯酸甲酯基网络稳定铁电液晶(PNSFLC)材料。采用热台偏光显微镜观察了由不同含量的甲基丙烯酸甲酯(MMA)制备的PNSFLC样品的网络织构。采用紫外分光光度计在0～30V的电压条件下研究了PNSFLC样品的电光性能。采用阿贝折射仪在0～70℃范围内,研究了PSFLC的折射率随温度变化的关系。结果表明:随着(MMA)含量的增加,聚合物网络结构由稀疏至致密。当MMA含量为7%时,所制备的PNSFLC样品的电光响应比小分子液晶的电光性能成线性好,且该MMA含量的PNSFLC样品的热稳定性较好。     

PDMS微/毫流控芯片的简易快速制备及其疏水性研究

将玻璃片/管、锡箔等材料进行组装、通道搭建制备出带有管路图案的容器,再将聚二甲基硅氧烷(PDMS)预聚体浇注到该容器中固化成型,之后通过模具拆卸、切割制备出整体式PDMS微/毫流控芯片.该法可获取各种微通道尺寸保真性好的整体式芯片,其通道截面圆形度与由热压法制备的微流控芯片相比有明显提高.另将获得的PDMS芯片经过30 min紫外改性后,其疏水性得到明显改善,与H2O的接触角由钝角变为了锐角,并在室温下静置能维持1 h左右的改性,完全能够满足液滴成型实验的时间要求.另外将该法制备的PDMS整体式芯片用于单分散液滴、双重液滴制备时,可在较宽的流速范围(4 mL/h~36 mL/h)内得到粒径可控的液滴,并且液滴在芯片通道中不易破乳,表现出良好的稳定性.这对于靶球制备、功能材料合成、活性成分保持等应用有重要意义.     

空间太阳电池玻璃盖板表面超薄ITO防静电层的设计及制备工艺

ITO/MgF2复合薄膜既具有较好的表面导电性能又具有较高的透过率,可应用于空间太阳电池玻璃盖板表面。文章主要对ITO/MgF2复合薄膜中表层的超薄ITO薄膜进行了研究。利用TFCalc软件模拟了ITO薄膜厚度对ITO/MgF2复合薄膜光学性能的影响,根据模拟结果采用电子束蒸发法在衬底上依次沉积MgF2薄膜和氧化铟锡(ITO)薄膜,研究了ITO薄膜工艺参数(沉积速率、沉积温度和工作气压)和ITO薄膜厚度对ITO/MgF2复合薄膜光电性能及微观结构的影响。当ITO薄膜沉积速率为0.05nm/s、沉积温度为400℃、工作气压为2.3×10~(-2) Pa、厚度为10nm时,表层ITO薄膜基本连续,其方块电阻(1.94kΩ/)已符合设计需求,ITO/MgF2复合薄膜在可见光区间(400~800nm)的平均透过率达到89.00%。     

制备工艺对纳米级铟锡氧化物(ITO)形貌和电性能的影响

以SnCl4·5H2O、In和浓盐酸为原料,采用化学共沉淀法制备出了纳米级锡掺杂氧化铟(ITO)导电微粉,系统地研究了掺杂量,共沉淀温度,pH值,热处理时间、温度对粉体粒度、形貌和电性能的影响规律。研究表明,合成的ITO粉体分散性较好、导电性能优异,粒径在40nm左右具有立方铁锰矿结构。在ITO纳米导电粉的制备过程中,共沉淀温度和滴定终点pH值对其形貌和性能有很大影响,当共沉淀温度在60℃左右,pH=6时制得的粉体性能最佳。煅烧条件对粉体的形貌、粒度和导电性也有较大的影响,在700℃,4h条件下可以制得导电性能良好,结晶完好,粒度分布均匀的ITO粉体。掺入Sn(Ⅳ)的量对载流子的迁移率有很大的影响,在掺杂浓度为10%左右可制得导电性极佳的纳米ITO粉体。     

Soft chemistry based sponge-like indium tin oxide (ITO) ---- a prospective component of photoanode for solar cell application

Previously we reported the synthesis of novel organic-inorganic composite indium tin oxide (ITO) foam precursor leading to the formation of “sponge-like” ITO by burning away the organics. This newly made sponge-like ITO possesses relatively high electrical conductivity due to phonon confinement with reasonable pore structure and may have potential application as functional materials in semiconducting dye absorbing layer in dye-sensitized solar cell (DSSC) and also as the receptor of electrons injected from the quantum dots (QDs) of organic--inorganic hybrid QD based solar cell. This report is a short review of “sponge-like” ITO described as a lecture note on its future use as an alternative new prospective material for photoanode of solar cell in the domain of sustainable energy.     

Growth and characterization of indium tin oxide thin films deposited on PET substrates

Transparent and conductive indium tin oxide (ITO) thin films were deposited onto polyethylene terephthalate (PET) by d.c. magnetron sputtering as the front and back electrical contact for applications in flexible displays and optoelectronic devices. In addition, ITO powder was used for sputter target in order to reduce the cost and time of the film formation processes. As the sputtering power and pressure increased, the electrical conductivity of ITO films decreased. The films were increasingly dark gray colored as the sputtering power increased, resulting in the loss of transmittance of the films. When the pressure during deposition was higher, however, the optical transmittance improved at visible region of light. ITO films deposited onto PET have shown similar optical transmittance and electrical resistivity, in comparison with films onto glass substrate. High quality films with resistivity as low as 2.5 × 10^− 3 Ω cm and transmittance over 80% have been obtained on to PET substrate by suitably controlling the deposition parameters.     

Laser direct write patterning technique of indium tin oxide film

The circuit patterns of transparent conductive oxide films (TCO films) have widely formed using the traditional photolithography method. The indium tin oxide (ITO) films of flat panel displays are one of the TCO films and usually ablated using the wet etching, which is widely adopted in the semiconductor processing. However, the chemical wet etching techniques usually appear with more disadvantages in the procedure, including the chemical pollution, the under-cut effect, the swelling and the costly. Therefore, the dry etching would be replaced the photolithography procedures. The laser directing method is one of the dry etching techniques and could form the circuit pattern on the ITO glasses. Moreover, the laser directing techniques could flexibility make the circuit pattern in the TCO film and the substrate would be not eroded by the laser ablation. The investigation is interested in circuit patterning of glass substrate using the laser direct writing techniques to ablate the ITO films by a UV laser materials processing system. The UV laser is a third-harmonic Nd: YAG laser with a 355 nm of wavelength and the power is 1.0 W. In this paper, the ITO films are ablated by the UV laser materials processing system which used the different repetition rate and the feeding speeds of tables. The results of laser pattering of ITO films are measured using the optical microscope (OM) and the scanning electron microscope (SEM), and it indicates the repetition rate of laser would affect the width of line.     

Electrical and optical properties of indium tin oxide films prepared on plastic substrates by radio frequency magnetron sputtering

The influence of deposition power, thickness and oxygen gas flow rate on electrical and optical properties of indium tin oxide (ITO) films deposited on flexible, transparent substrates, such as polycarbonate (PC) and metallocene cyclo-olefin copolymers (mCOC), at room temperature was studied. The ITO films were prepared by radio frequency magnetron sputtering with the target made by sintering a mixture of 90 wt.% of indium oxide (In₂O₃) and 10 wt.% of tin oxide (SnO₂). The results show that (1) average transmission in the visible range (400-700 nm) was about 85%-90%, and (2) ITO films deposited on glass, PC and mCOC at 100 W without supplying additional oxygen gas had optimum resistivity of 6.35 × 10⁻⁴ Ω-cm, 5.86 × 10⁻⁴ Ω-cm and 6.72 × 10⁻⁴ Ω-cm, respectively. In terms of both electrical and optical properties of indium tin oxide films, the optimum thickness was observed to be 150-300 nm.     

Conductivity and adhesion enhancement in low-temperature processed indium tin oxide/polymer nanocomposites

We report on the conductivity and adhesion enhancement of indium tin oxide (In₂O₃:Sn; ITO) nanoparticle films by the application of polymers as matrix material. We fabricated ITO layers at a maximum process temperature of 130 °C by modifying and spin-coating nanoparticulate ITO dispersions. Dispersions containing the organic film-forming agent polyvinylpyrrolidone (PVP) and the organofunctional coupling agent 3-methacryloxypropyltrimethoxysilane (MPTS) have been developed to obtain transparent and conducting coatings on substrates which do not withstand high process temperatures like polymers or already processed glasses. The layers were cured by UV-irradiation as well as by low-temperature heat treatment (T = 130 °C) in air and under forming gas atmosphere (N₂/H₂). The influence of the additives on the electrical, optical, morphological and mechanical layer properties is reported. Compared to best pure ITO layers (3.1 Ω^− 1 cm^− 1), the ITO-MPTS-PVP nanocomposite coatings exhibit a conductance of 9.8 Ω^− 1 cm^− 1. Stable sheet resistances of 750 Ω/□ at a coexistent transmittance of 86% at 550 nm for a layer thickness of about 1.3 µm were achieved. The conductance enhancement is a consequence of the consolidation of the ITO nanoparticle network due to the acting shrinkage forces caused either by drying in the case of PVP or UV-irradiation induced condensation and polymerization reactions in the case of MPTS.     

水热法合成铟锡氧化物纳米粒子的制备及表征

采用三氧化二铟和真空蒸发法制得的纳米锡粉为原料，溶解在一定浓度的氢氧化钠溶液中，水热条件下成功的合成了纳米级的铟锡氧化物粒子，通过粉末X射线衍射（XRD），场发射扫描电子显微镜（FE-SEM），透射电子显微镜（TEM）和紫外可见光光吸收光谱（Uv-Vis）等手段对所得产物进行表征。讨论了反应时间、pH值因素对产物成分和形貌的影响。结果表明：在温度为180℃，10mol／L NaOH溶液的条件下，水热反应36h得到比较均一的产物In1.94Sn0.06O3，产物形貌为均匀的六面体，大小在100nm左右，且对波长在200-400nm的光有强烈的吸收。     

Low-temperature processing of transparent conductive indium tin oxide nanocomposites using polyvinyl derivatives

We report on the influence of additives on the electrical, optical, morphological and mechanical properties of transparent conductive indium tin oxide (In₂O₃:Sn; ITO) nanoparticle films by the use of polymers as matrix material. Key issues to fabricate layers suitable for use in electronic device applications are presented. Polyvinyl derivatives polyvinyl acetate, polyvinyl alcohol (PVA) and polyvinyl butyral were applied and their suitability to form transparent conductive ITO nanocomposite coatings at a maximum process temperature of 130 °C was investigated. A low-temperature treatment with UV-light has been developed to provide the possibility of curing ITO thin films deposited on substrates which do not withstand high process temperatures. Compared to best pure ITO layers (0.2 Ω^− 1 cm^− 1), the ITO-PVA nanocomposite coatings show a conductance value of 4.1 Ω^− 1 cm^− 1 and 5.9 Ω^− 1 cm^− 1 after reducing in forming gas. Sheet resistance of ca. 1200 Ω/□ with coexistent transmittance of 85% at 550 nm for a layer thickness of about 1.45 μm was achieved. The conductance enhancement is a consequence of nanoparticulate ITO network densification due to the acting shrinkage forces caused by the polymer matrix during film drying and additionally UV-induced crosslinking of PVA.     

Immobilization of aromatic aldehyde molecules on indium tin oxide surface using acetalization reaction

We demonstrated an acetalization reaction as a versatile method to immobilize aromatic aldehyde molecules on surfaces of metal oxides, silicon dioxide, and indium tin oxide. First, a trimethylsily (TMS) terminated surface was formed using a silylation reaction between a chloride group of trimethylsilychloride and a hydroxyl group of the substrate surfaces. Second, terephthalaldehyde (TPA) was immobilized on the surfaces using an acetalization reaction between the TMS-terminated surface and an aldehyde group of TPA. Results of contact angle, X-ray photoelectron, and ultraviolet absorption spectra revealed that the TPA molecules on the surfaces were well-packed with a high surface density.