1,4-二叠氮-2,3-二叠氮甲基-2,3-二硝基丁烷的合成

以硝基甲烷为原料合成了1,4-二叠氮-2,3-二叠氮甲基-2,3-二硝基丁烷,总收率为37.8%。采用1HNMR﹑IR和MS对目标产物及中间体的结构进行了表征。在三羟甲基硝基甲烷的合成中,结合反应机理确定了氢氧化钙的用量为:n(CH3NO2)n(Ca(OH)2)=1001;通过对催化剂浓硫酸﹑三氟化硼—乙醚络合物和对甲苯磺酸的比较,得出对甲苯磺酸为中间体2,2-二甲基-5-羟甲基-5-硝基-1,3-二氧杂环己烷合成的较优催化剂;分别采用2,3-二羟甲基-2,3-二硝基-1,4-丁二醇四硝酸酯和2,3-二羟甲基-2,3-二硝基-1,4-丁二醇四对甲苯磺酸酯与NaN3反应,发现磺酸酯基易离去,叠氮化反应更易进行,收率较高;叠氮化反应的较优溶剂为DMSO。DSC分析表明,1,4-二叠氮-2,3-二叠氮甲基-2,3-二硝基丁烷的分解峰温为223.46℃。     

3,5-二硝基吡唑-4-硝酸酯的合成及热分解机理研究

以4-氯吡唑为原料,经过硝硫混酸硝化制得4-氯-3,5-二硝基吡唑,再以硝酸根为亲核试剂进行亲核取代反应得到一种新型的含能化合物3,5-二硝基吡唑-4-硝酸酯,并采用红外光谱、核磁共振、元素分析对产物结构进行了表征。计算了爆轰性能并与常规含能化合物进行了比较。采用TG-DSC-MS联用方法对其热分解机理进行了研究。结果表明,3,5-二硝基吡唑-4-硝酸酯的爆轰性能接近于黑索金与奥克托金而优于梯恩梯。DNPN的热分解机理可能是,首先O—NO_2键断裂,接着硝基吡唑发生硝基自由基或者亚硝基自由基断裂,最后吡唑环开环生成N_2、NO、N_2O以及CO_2等产物。     

二硝基乙腈钾与火药组分相容性的DSC法评估

为了了解二硝基乙腈钾(DNCK)与火药常用组分之间的相容性,采用差示扫描量热法（DSC）研究了DNCK与这些组分之间的相互作用。结果表明:DNCK与DAGR吸收药、DA吸收药、硝化棉（NC）、硝基胍（NQ）、叠氮硝胺（DIANP）、1,3-二甲基-1,3-二苯基脲（C2）、2-硝基二苯胺（2-NDPA）相容性良好;与六硝基六氮杂异戊兹烷（CL-20）和N 甲基-4-硝基苯胺（MNA）轻微敏感;与黑索今（RDX）、三羟甲基乙烷三硝酸酯（TMETN）和间苯二酚（Res）敏感;DNCK与奥克托今（HMX）和N-丁基硝氧乙基硝胺（BUNENA）混合体系的分解峰温较HMX和BUNENA单质组分分别提前了35.2 ℃和17.4 ℃,因此,与HMX和BUNENA不相容。     

化学工程技术中微化工技术的应用研究

微化工技术是当前化学工程领域的研究前沿与热点。本文就微化工技术在气-液和液-液两相反应体系中的应用,阐释微反应器内进行化学反应的可行性。     

微反应器技术及其在化工生产中的应用

作为一种全新的工艺过程强化技术,微反应器技术在化工生产中的应用与日俱增。本文以该技术在几种化工产品生产中的应用为例,介绍了微反应器技术的优势,分析了如何根据化学反应特点,设计微反应工艺路线,选择关键微反应设备,从而实现工艺优化的过程。     

叠层法制备玻璃陶瓷微通道反应器的研究

以60%(质量分数)的硼硅酸盐玻璃粉体与40%(质量分数)的Al2O3复合后获得的玻璃陶瓷粉体为固相,利用水性苯丙乳胶作为粘结剂得到了性能较好、结构均匀、高致密度、无毒环保的玻璃陶瓷流延片。通过室温直接叠层获得了微通道反应器原型器件。在860℃烧结后,微通道反应器原型器件的相对密度最大可达93.38%,体积密度达2.48g/cm3。所制备原型器件的T型通道在烧结后形状规则、无变形,说明利用水基流延叠层工艺制备微通道反应器是可行的。     

强化液相沉淀微观混合制备药物纳微颗粒

采用反溶剂和反应沉淀方法,利用微通道反应器和超重力反应器强化液相沉淀微观混合,制备模型药物枸橼酸喷托维林纳微颗粒并分析颗粒性质。结果表明:新型反应器能够通过强化液相沉淀微观混合制备得到药物纳微颗粒,颗粒为片状结晶,粒径在100~200 nm,制备过程中药物微观物相结构未发生改变;其中反溶剂沉淀为快速物理过程,适于强化微观混合,超重力反应器具有最高的制备效率。     

新型烷基化壳聚糖微球的制备及其吸附性能

制备N-烷基化改性壳聚糖微球,研究了溶液pH值、2,4-二硝基酚浓度,温度和氯化钠含量等因素对其吸附性能的影响.结果表明,庚醛改性壳聚糖微球具有较好的抗酸碱性能;溶液的pH值对庚醛改性壳聚糖微球吸附性能的影响较大,pH值为3.6,吸附时间为1 h时,对2,4-二硝基酚的吸附量最大(达到400 mg·g-1);2,4-二硝基酚浓度对吸附的影响符合Freundlich等温方程;改性壳聚糖微球对2,4-二硝基酚的吸附性能明显优于未改性的壳聚糖,对浓度为15 mg·L-1的2,4-二硝基酚溶液的吸附量分别为3.0 mg·g-1和1.45 mg·g-1.     

含能增塑剂2,3-二羟甲基-2,3-二硝基-1,4-丁二醇四苯甲酸酯的合成及表征

以2,3-二羟甲基-2,3-二硝基-1,4-丁二醇(BHDB)和苯甲酸为原料,4-二甲氨基吡啶(DMAP)为活化剂,N,N'-二环己基碳二亚胺(DCC)为脱水剂,通过酯化反应得到含能增塑剂2,3-二羟甲基-2,3-二硝基-1,4-丁二醇四苯甲酸酯(BHDBTB),对产物进行了~1H NMR、~(13)C NMR、IR等结构表征。X-射线单晶衍射说明,BHDBTB晶系属于三斜晶系,空间群为P-1,Mr=656.58。晶体的数据为:a=8.851 nm,b=9.373 nm,c=10.211 nm,α=82.61°,β=83.31°,γ=67.74°,V=775.3 nm3,Z=2,Dc=1.406 g/cm3,R1=0.083 6,Rw2=0.086 1。     

酮戊二酸改性壳聚糖微球的制备及吸附性能

采用反相悬浮法制备交联壳聚糖微球,再与α-酮戊二酸反应生成Schiff碱,NaBH4还原制得改性壳聚糖微球。用FT-IR、SEM和XRD进行表征,并用于吸附2,4-二硝基酚研究。考察了吸附时间、溶液pH值、2,4-二硝基酚浓度、温度、NaCl含量等因素对吸附的影响。结果表明,α-酮戊二酸改性交联壳聚糖微球对2,4-二硝基酚有较好的吸附性能,在pH为3.6时,30 min吸附量达372.2 mg/g,吸附数据符合Freundlich等温方程。     

Organic microchemical performance of solvent resistant polycarbosilane based microreactor

We report the successful fabrication of preceramic polymer allylhydridopolycarbosilane (AHPCS) derived microchannels with excellent organic solvent resistance and optical transparency via economic imprinting process, followed by UV and post thermal curing process at 160 degrees C for 3 h. The microchemical performance of the fabricated microreactors was evaluated by choosing two model micro chemical reactions under organic solvent conditions; syntheses of 2-aminothiazole in DMF and dimethylpyrazole in THF, and compared with glass-based microreactor having identical dimensions and batch system with analogy. It is clear that AHPCS derived microreactor showed excellent solvent resistance and chemical stability compare with glass derived microreactor made by high cost of photolithography and thermal bonding process. The novel preceramic polymer derived microreactors showed reliable mechanical and chemical stability and conversion yields compare with that of glass derived microreactors, which is very promising for developing an integrated microfluidics by adopting available microstructuring techniques of the polymers.     

Performance of an integrated microoptical system for fluorescence detection in microfluidic systems

This article presents a new integrated microfluidic/microoptic device designed for basic biochemical analysis. The microfluidic network is wet-etched in a Borofloat 33 (Pyrex) glass wafer and sealed by means of a second wafer. Unlike other similar microfluidic systems, elements of the detection system are realized with the help of microfabrication techniques and directly deposited on both sides of the microchemical chip. The detection system is composed of the combination of refractive circular or elliptical microlens arrays and chromium aperture arrays. The microfluidic channels are 60 microm wide and 25 microm deep. The elliptical microlenses have a major axis of 400 microm and a minor axis of 350 microm. The circular microlens diameters range from 280 microm to 350 microm. The apertures deposited on the outer chip surfaces are etched in a 3000-A-thick chromium layer. The overall thickness of this microchemical system is < 1.6 mm. A limit of detection of 3.3 nM for a Cy5 solution in phosphate buffer (pH 7.4) was demonstrated. The cross-talk signal measured between two adjacent microchannels with 1 mm pitch was < 1:5600, meaning that < or = 1.8 x 10(-4)% of the fluorescence light power emitted from one microchannel filled with a 50 microM Cy5 solution reaches the photodetector at the adjacent microchannel. This performance compares very well with that obtainable in microchemical chips using confocal fluorescence systems, taking differences in parameters, such as excitation power into microchannels, data acquisition rates, and signal filtering into account.     

Mixing processes in a zigzag microchannel: finite element simulations and optical study

A finite element model has been used in order to study the mixing process of species in a 100-microm-wide zigzag microchannel integrating a "Y" inlet junction. The distribution of the concentration was obtained by solving successively the Navier-Stokes equation and the diffusion-convection equation in the steady state form. Because of the large range of Reynolds numbers studied (1 < Re < 800), the 2D diffusion-convection simulations are carried out with high diffusion coefficients. The results illustrated the effects of both flow rate and channel geometry on hydrodynamics and mixing efficiency. Below a critical Reynolds number of approximately 80, the mixing is entirely ensured by molecular diffusion. For higher Reynolds numbers, simulations revealed the mixing contribution of laminar flow recirculations. This effect increases for lower values of diffusion coefficients. Experimental studies on the mixing of species at different flow rates are reported showing the same hydrodynamic tendency.     

Temperature alternation by an on-chip microheater to reveal enzymatic activity of beta-galactosidase at high temperatures

A method to measure enzymatic activity at high temperatures by rapid temperature alternation of a microreactor with a microheater is proposed. On-chip microreactor and microheater were integrated on a glass plate by MEMS technology; this microheater can control the temperature of the microreactor with a response speed of 34.2 and 31.5 K/s for temperature rise and fall, respectively, with an accuracy of 3 degrees C. The enzyme, beta-galactosidase, was revealed to survive short exposure (4-s pulses) to temperatures above that which would "normally" denature them. Its activity at 60 degrees C was revealed to be approximately 4 times greater than that at room temperature. This method not only gives new kinetic information in biochemistry but also enables application in highly sensitive biosensors.     

Characterization of mixing performance in a microreactor and its application to the synthesis of porous coordination polymer particles

Here we quantitatively evaluated the mixing performance of a tailor-made microreactor with central-collision type through the iodide/iodate chemical test reaction, and applied the microreactor to the synthesis of zeolitic imidazolate framework-8 (ZIF-8), which is a subclass of porous coordination polymers (PCPs) or metal organic frameworks (MOFs). The chemical test reaction demonstrated excellent mixing performance of the microreactor with a characteristic mixing time shorter than 1 ms, which is approximately 100 times faster than those of a batch reactor and a millimeter-sized Y-shaped mixer. Taking advantage of the rapid and uniform mixing, the microreactor successfully produced ZIF-8 particles with high reproducibility by simply mixing aqueous solutions of zinc nitrate and 2-methylimidazole. The synthesis at room temperature resulted in ZIF-8 particles with chamfered cube shape, while a lower temperature of 5 °C produced raspberry-type spherical particles. We confirmed that prepared ZIF-8 particles have BET surface area of ～1500 m²/g and exhibit the gate adsorption behavior caused by the structural transition of the ZIF-8 framework.     

Nitrification of industrial and domestic saline wastewaters in moving bed biofilm reactor and sequencing batch reactor

Nitrification of saline wastewaters was investigated in bench-scale moving-bed biofilm reactors (MBBR). Wastewater from a chemical industry and domestic sewage, both treated by the activated sludge process, were fed to moving-bed reactors. The industrial wastewater contained 8000 mg Cl(-)/L and the salinity of the treated sewage was gradually increased until that level. Residual substances present in the treated industrial wastewater had a strong inhibitory effect on the nitrification process. Assays to determine inhibitory effects were performed with the industrial wastewater, which was submitted to ozonation and carbon adsorption pretreatments. The latter treatment was effective for dissolved organic carbon (DOC) removal and improved nitrification efficiency. Nitrification percentage of the treated domestic sewage was higher than 90% for all tested chloride concentrations up to 8000 mg/L. Results obtained in a sequencing batch reactor (SBR) were consistent with those attained in the MBBR systems, allowing tertiary nitrification and providing adequate conditions for adaptation of nitrifying microorganisms even under stressing and inhibitory conditions.     

不可逆封合微流控芯片中高活性蛋白质阵列的制备

保持生物分子的高活性是在不可逆封合微流控芯片中构筑微阵列芯片的关键问题.首先,利用MEMS技术和表面修饰方法制作了一种聚二甲基硅氧烷(PDMS)/玻璃芯片.应用光刻技术制作了PDMS盖片上的通道,同时用光刻剥离技术制作了玻璃基片上的金膜图案.进而,使用双官能团修饰剂3-氨丙基三甲氧基硅氧烷(APTMS)在玻璃基体和金膜图案上进行选择性表面修饰以吸附形成蛋白质阵列,并在其上覆盖一层水溶性聚乙烯醇(PVA)来保护蛋白质,既可避免其在加热处理过程中的高温伤害,又能防止在PDMS盖片与玻璃基片进行不可逆封合过程中的氧等离子体轰击造成的活性伤害.然后,通入水溶液冲洗除去PVA膜.使用荧光显微镜和原子力显微镜(AFM)考察蛋白质阵列质量,并结合免疫反应实验和细胞捕获固定实验评估蛋白质阵列的活性.结果表明,使用该方法可在不可逆封合的微流控芯片制作中构筑具有直径为200μm的高分辨率蛋白质阵列图案,蛋白质保持高的免疫活性,且可用于固定Hela细胞.     

纺织配棉流程棉纤维快速测量技术及其应用

针对国内纺织企业开始在配棉生产流程使用棉纤维快速测量技术来取代手工目测等落后、传统方法的现状,介绍大容量棉纤维性能测试仪的工作原理、技术特征、特点,以及棉纤维快速测量技术与传统方法生产效率的对比.通过大容量棉纤维性能测试仪在配棉流程的应用,认为:棉纤维性能快速测试技术使得纺织生产过程的棉花测试方法有了一个质的飞跃,为纺织企业配棉自动化提供了有力保证.     

Fabrication of microfluidic reactors and mixing studies for luciferase detection

We report the detection of luciferase by implementing a bioluminescent assay in microfluidic reactors. The reactors were fabricated in poly(methyl methacrylate) by hot embossing using a mold master with the reactor layouts made by high-precision micromilling. The overall fabrication process was simple to implement and had a quick turnaround time with low cost. Two reactors, one with smooth channels (called reactor I) and the other with staggered herringbone mixers (called reactor II), were studied for the bioluminescent assay. The assay was implemented by introducing a sample and an assay solution into the reactors and then mixing took place to achieve the enzymatic reactions. We found that the mixing efficiency in reactor II was 17.8 times higher than reactor I. Theoretical analysis of the experimental results indicated that the required channel length of mixing was linearly proportional to the flow rate. A calibration curve for luciferase was obtained for both reactors. We found that the detection sensitivity of reactor II was 3 times higher than reactor I. The limit of detection in reactor II was determined to be 0.14 microg/mL luciferase. The device was further exploited to determine the concentration of luciferase samples obtained from in vitro protein expression.