基于树状PAMAM修饰的PDMS微流控芯片分离检测两种蛋白质

为提高聚二甲基硅氧烷(PDMS)微流体芯片的亲水性,抑制其对蛋白质的吸附,利用树状PAMAM通过物理涂覆的手段对其微通道的表面进行了修饰。对修饰后PDMS微流控芯片的亲水性和电渗流进行了考察,同时利用修饰后芯片对溶菌酶,核糖核酸酶A两种蛋白质进行了分离检测。结果表明,修饰后的PDMS微流控芯片微通道表面形成了一层均匀、稳定的亲水性涂层,有效抑制了对蛋白质的吸附,成功地对溶菌酶和核糖核酸酶A实现了分离,柱效分别达到6.93×104plates/m和7.92×104plates/m,同时修饰后的芯片具有良好的重现性和较长的使用寿命。     

PDMS微流控芯片-光纤传感器系统测定载脂蛋白apoB 100

以聚二甲基硅氧烷(PDMS)材料为研究对象,在微流控反应芯片内通过氧等离子体处理和聚乙烯亚胺-戊二醛交联法修饰PDMS微通道表面,实现了芯片内apoB 100的快速捕获和检测。设计了分立的集成了光纤传感器和"U"型PDMS微流控芯片的检测体系,根据催化反应前后颜色变化测定apoB 100浓度,消除了复杂的生物化学环境对光学检测的干扰。测试结果表明,由于微通道具有的较大的表面积/体积比,微流控免疫芯片把整个免疫反应及检测过程缩短至1h以内。该方法的检测限为1ng/mL,线性范围在1~20ng/mL。因此微流控免疫芯片-光纤传感器检测系统在临床应用和现场检测领域具有较大的发展潜力。     

基于黏弹性模型的PMMA微流控芯片模内键合微通道变形研究

针对聚合物微流控芯片模内键合过程中微通道变形的问题,采用黏弹性材料模型对聚甲基丙烯酸甲酯(PMMA)微流控芯片模内键合过程中具有梯形截面的微通道变形进行了仿真分析;研究了在105℃下,芯片微通道在不同键合压力和键合时间下微通道的变形。结果表明:微通道不能保持键合前的尺寸,温升对微通道变形影响很小;微通道顶部与两侧的黏合使得微通道顶部宽度和微通道高度变形远大于底部宽度变形,并随着键合压力的增大而增大;当键合时间超过50 s后,键合时间对微通道变形影响很小,可以采用较长的键合时间来保证键合强度而不影响微通道形貌。     

PDMS微流控芯片-光纤传感器系统测定载脂蛋白apoB 10

以聚二甲基硅氧烷(PDMS)材料为研究对象,在微流控反应芯片内通过氧等离子体处理和聚乙烯亚胺-戊二醛交联法修饰PDMS微通道表面,实现了芯片内apoB 100的快速捕获和检测。设计了分立的集成了光纤传感器和"U"型PDMS微流控芯片的检测体系,根据催化反应前后颜色变化测定apoB 100浓度,消除了复杂的生物化学环境对光学检测的干扰。测试结果表明,由于微通道具有的较大的表面积/体积比,微流控免疫芯片把整个免疫反应及检测过程缩短至1h以内。该方法的检测限为1ng/mL,线性范围在1~20ng/mL。因此微流控免疫芯片-光纤传感器检测系统在临床应用和现场检测领域具有较大的发展潜力。     

聚(双环戊二烯-co-环辛二烯)微流控芯片的制备

本文报道了聚(双环戊二烯-co-环辛二烯)微流控芯片的制备方法。引入环辛二烯作为共聚单体,与双环戊二烯通过开环易位聚合制备得到弹性共聚物。当环戊二烯与环辛烯的质量比是1 : 1时,制得共聚物的力学性能接近于聚二甲基硅氧烷(PDMS),弹性共聚物具有较高的微尺寸结构成型精度。利用聚双环戊二烯半固化凝胶的反应特性,实现共聚物与聚双环戊二烯基底之间的稳定键合。共聚物微流控芯片可以通过类似于PDMS的连接方式,实现简单、高效的密封连接。利用共聚物微流控芯片制得单分散的微液滴,控制连续相的流速即可实现微液滴尺寸的调变。关键词：聚双环戊二烯共聚物；环辛烯；弹性体；微流控芯片；单分散液滴；中图分类号：TQ630 文献标识码： A 文章编号：1003-5214 (2020) 01-0000-00     

图案化二维有序大孔SiC制备

以苯乙烯为单体,采用分散聚合法合成粒径不同且单分散性良好的聚苯乙烯微球.将1.5 μm聚苯乙烯微球排列在图案化聚二甲基硅氧烷模具(PDMS mold)中,以此为模板,经过浸渍SiC陶瓷前驱体(聚碳硅烷)、紫外固化和高温焙烧过程,成功制备了二维有序大孔SiC陶瓷阵列.扫描电镜(SEM)照片表明二维有序大孔SiC形貌受聚苯乙烯微球模板调控.通过改变聚碳硅烷涂层的厚度,能够进一步调控二维有序大孔SiC的孔径.     

酸酐固化聚二甲基硅氧烷改性环氧树脂体系的研究

合成了聚二甲基硅氧烷与环氧树脂的增容剂，以甲基四氢苯酐为固化剂固化聚二甲基硅氧烷改性环氧树脂体系，通过测定，中击强度、拉伸强度、弯曲强度分析了其增韧增强效果。结果表明，增容剂的加入提高了环氧树脂与聚二甲基硅氧烷的相容性，当聚二甲基硅氧烷的含量为10％时，改性环氧树脂体系的力学性能最好；并通过热失重法、差示扫描量热法测定了固化物的热性能，其耐热稳定性与纯环氧树脂相比有明显提高。     

单组分脱醇型室温固化硅橡胶储存稳定性的研究进展

介绍了脱醇型RTV-1(单组分室温固化)硅橡胶的优点。重点综述了解决脱醇型RTV-1硅橡胶储存稳定性的方法,包括生产过程中严格控制胶料中的水分、向胶料中添加羟基清除剂以及用端烷氧基聚二甲基硅氧烷代替端羟基聚二甲基硅氧烷作为基础胶料。最后对脱醇型RTV-1硅橡胶的应用及发展方向进行了展望。     

三维复杂微流体纺丝芯片的封装研究

为了拓展微流体芯片的应用领域,以一种具有三层结构的多功能集成微流体纺丝芯片为例,利用去离子水和再生丝素蛋白水溶液,比较了环氧树脂粘合剂、硅胶粘合剂以及压敏胶对聚二甲基硅氧烷(PDMS)和纤维素膜的粘合效果,探讨了等离子处理、封装方式等三维复杂微流体芯片的封装技术,实现了多功能集成微流体纺丝芯片的有效封装,对具有类似结构的三维复杂微流体芯片的封装提供参考。     

IPN中聚氨酯固化反应动力学的FTIR研究

用傅立叶变换红外光谱(FTIR)研究纯聚氨酯弹性体和聚氨酯/聚二甲基硅氧烷IPN中聚氨酯的固化反应动力学。结果表明,在PU/PDMS IPN体系中聚氩酯的交联反应仍为二级反应,聚二甲基硅氧烷的存在大大降低了PU/PDMS IPN的交联速率,并提高了反应活化能。     

A Parametric Study of a Monolithic Microfluidic System for On-Chip Biomolecular Separation

A microfabricated poly(dimethylsiloxane) (PDMS) chip containing channel filled with polymer monolith has been developed for on-chip biomolecule separation. Methacrylate monolithic polymers were prepared by photo-initiated polymerization within the channel to serve as a continuous stationary phase. The monolithic polymer was functionalized with a weak anion-exchange ligand, and key parameters affecting the binding characteristics of the system were investigated. The total binding capacity was unaffected by the flow rate of the mobile phase but varied significantly with changes in ionic strength and pH of the binding buffer. The binding capacity decreased with increasing buffer ionic strength, and this is due to the limited available binding sites for protein adsorption resulting from cationic shielding effect. Similarly, the binding capacity decreased with decreasing buffer pH towards the isoelectric point of the protein. A protein mixture, BSA and ovalbumin, was used to illustrate the capacity of the methacrylate-based microfluidic chip for rapid biomolecule separation.     

Fabrication and characterization of a flow-through PCR device with integrated chromium resistive heaters

A flow-through PCR device with integrated chromium resistive heaters was developed. The PCR device was composed of a polydimethylsiloxane flow channel chip fabricated using soft lithography and a glass heating chip produced by standard photolithography. PDMS bonding layers were used to assemble the device instead of oxygen plasma treatment. The formation of air bubbles within the device was suppressed by treating the flow channel with 20% (v/v) Tween 20. DNA fragments with different lengths (219, 298, and 842 bp) were successfully amplified with the device. For the 298 bp fragment, 30 thermal cycles were completed in 23 min and a clear product band was observed after gel electrophoresis. The device showed no cross contamination after appropriate washing. Two commonly used PCR additives, bovine serum albumin and polyethylene glycol, showed inhibitory effect in the Tween 20 treated PCR device.     

187 dtex/288 f细旦阻燃涤纶长丝制备工艺

通过用实验机和在线生产,对用TCS法生产的细旦阻燃涤纶长丝的工艺条件,如切片含水率、纺丝温度、冷却成形、丝条上油率、热管温度及热管位置等工艺参数进行了研究。结果表明:采用合理的干燥工艺可获得含水率稳定在1.8×10-5以内的阻燃干切片;1#联苯锅炉温度控制在265～267℃,2#联苯锅炉温度控制在269～271℃;侧吹风风温为(21±1)℃、风速0.45m/s、风湿70%±5%;丝条上油率1%～1.2%;热管温度168～170℃,位置距喷丝板高度910mm时,可生产出质量优良的细旦阻燃涤纶长丝。     

连通微通道内过冷流动沸腾传热强化机理分析

连通微通道（平行主通道由支流通道连通）流动沸腾传热具有优越的换热性能,但其传热传质强化机理尚不够明确,限制了其实际应用。鉴于此,本文基于流体体积函数（VOF）方法,对连通微通道内过冷流动沸腾进行二维非稳态数值模拟,研究了流场扰动、脱落汽泡与壁面间的薄液膜分布对微通道当地传热系数的影响规律。结果表明,连通微通道存在两种强化换热机理：支流通道脱落汽泡可增强主通道流场扰动,进而促进了通道热边界层再发展;脱落汽泡与热壁面间可形成薄液膜,该薄液膜减小了换热热阻。同时研究了支流通道倾角（θ）对连通微通道强化换热的影响,结果发现,不同θ时,连通微通道整体平均传热系数提高10.51%~17.66%,单个主通道平均传热系数最高可提升27.94%,且θ=45°时连通微通道具有最佳换热特性。该研究有望为芯片高效冷却结构的设计提供指导。     

Enhancing performance of a miniaturized surface plasmon resonance sensor in the reflectance detection mode using a waveguide-coupled bimetallic chip

The characteristics of a waveguide-coupled bimetallic (WcBiM) chip in a miniaturized surface plasmon resonance (SPR) sensor and its detection capability for a low molecular weight biomolecule were investigated. The configuration of the WcBiM chip was gold (Au)/waveguide (ZnS-SiO₂)/silver (Ag). In the intensity measurement mode, the sensitivity could be improved by reducing the full width at half maximum (FWHM) of the reflectance curve. The FWHM of the WcBiM chip is narrower than that of the Au chip, which suggests that the slope of the reflectance curve for the WcBiM chip is steeper. In order to generate enhanced resolution, the reflectance should be monitored at the specific angle where the slope is the steepest in the reflectance curve. For the detection of biotin that is a low molecular weight biomolecule, streptavidin was formed on the SPR sensor chip surface. The response of the SPR to biotin at various concentrations was then acquired. The sensitivities of the WcBiM chip and the Au chip were 0.0052%/(ng/ml) and 0.0021%/(ng/ml), respectively. The limit of detection of the biotin concentration for both the WcBiM and Au chips was calculated. The values were 2.87 ng/ml for the WcBiM chip and 16.63 ng/ml for the Au chip. Enhancement of the sensitivity in the intensity detection mode was achieved using the WcBiM chip compared with the Au chip. Therefore, sufficient sensitivity for the detection of a disease-related biomarker is attainable with the WcBiM chip in the intensity measurement mode using a miniaturized SPR sensor.     

Experimental and numerical analysis of high-resolution injection technique for capillary electrophoresis microchip

This study presents an experimental and numerical investigation on the use of high-resolution injection techniques to deliver sample plugs within a capillary electrophoresis (CE) microchip. The CE microfluidic device was integrated into a U-shaped injection system and an expansion chamber located at the inlet of the separation channel, which can miniize the sample leakage effect and deliver a high-quality sample plug into the separation channel so that the detection performance of the device is enhanced. The proposed 45° U-shaped injection system was investigated using a sample of Rhodamine B dye. Meanwhile, the analysis of the current CE microfluidic chip was studied by considering the separation of Hae III digested ϕx-174 DNA samples. The experimental and numerical results indicate that the included 45° U-shaped injector completely eliminates the sample leakage and an expansion separation channel with an expansion ratio of 2.5 delivers a sample plug with a perfect detection shape and highest concentration intensity, hence enabling an optimal injection and separation performance.     

Integrated sensitive on-chip ion field effect transistors based on wrinkled InGaAs nanomembranes

Self-organized wrinkling of pre-strained nanomembranes into nanochannels is used to fabricate a fully integrated nanofluidic device for the development of ion field effect transistors (IFETs). Constrained by the structure and shape of the membrane, the deterministic wrinkling process leads to a versatile variation of channel types such as straight two-way channels, three-way branched channels, or even four-way intersection channels. The fabrication of straight channels is well controllable and offers the opportunity to integrate multiple IFET devices into a single chip. Thus, several IFETs are fabricated on a single chip using a III-V semiconductor substrate to control the ion separation and to measure the ion current of a diluted potassium chloride electrolyte solution.     

PA66-LOY纺丝设备开发

利用普通PA66切片低速纺丝获取低取向卷绕丝,然后在一定条件下高倍拉伸而制造出高强度产业用纤维。从挤出机,纺丝箱,纺丝组件,侧吹风,下甬道,上油,卷绕机等方面介绍了PA66-LOY纺丝设备的开发。     

TCS法生产有色异形涤纶长丝工艺探讨

探索TCS法生产 92dtex/3 6f涤纶三叶形黑色长丝 ,生产工艺条件为 :干切片与色母粒含水率分别应小于 2 0 μg/g与 40 μg/g ,螺杆温度稍低于常规纺丝温度 ,热管温度 190℃ ,生产的有色异形涤纶长丝优等品率达 90 %。     

Design and Simulation of a Microfluidic Blood-Plasma Separation Chip Using Microchannel Structures

Current clinical methods for the separation of whole blood into blood cells and cell-free plasma are currently based on large facility equipment, such as centrifuges. The disadvantage of this process is that the patients must have assays performed at the hospital or laboratory where the separation facility is located. The present study presents a design for microfluidic chips with different microchannel structures, which utilizes backward facing step geometry and centrifugal force to extract the cell-free plasma from whole blood samples at the branch of the microchannel for further assay, avoiding the influence of blood cells. Numerical simulation was performed on a personal computer to analyze the effects of inlet velocity and the structures of the microchannel on the flow field and back–flow in the microchannel, as well as the efficiency of separation and the volumetric fraction of the flowrate of plasma extraction. The minimum radius of particles (R) that can be excluded from the side channel, and fraction of the volumetric flowrate were obtained to evaluate the efficiency of plasma extraction. Based on the numerical simulations, the design with both converging and bending channels was the best design among the four layouts proposed. In this design, the value of R could be set to less than the critical value (set as 1 µm because of the radius of platelets), and the volumetric fraction of the extraction flowrate was approximately 8.4% when Re was about 20. The preliminary experiments indicated the fluorescent particles with 2.5 µm in radius were successfully excluded from side (plasma outlet) channel of the microfluidic chip with converging a inlet channel and the bent microchannel, when the Reynolds number of the inlet flowrate equals 50.