基于表面增强拉曼光谱技术的多通道同时快速检测原烟中的多菌灵和甲基硫菌灵

基于表面增强拉曼光谱(SERS)高灵敏的分子结构表征优势,本文发展了一种结合便携式拉曼光谱仪,利用SERS实现原烟中广谱杀菌剂多菌灵和甲基硫菌灵的多通道同时快速检测方法.该方法首先对前处理技术进行了优化,将多菌灵与甲基硫菌灵分离于同一处理液的不同溶液层中,再利用便携式拉曼光谱仪进行检测,实现了一次前处理同时区分检测多菌...     

聚氯乙烯溶液浓度的拉曼光谱检测

借助拉曼光谱,对聚氯乙烯(PVC)-环己酮溶液的浓度进行了检测.通过偏最小二乘法(PLS)分析发现,第一项 PLS 成分(factor 1)的得分与 PVC 溶液浓度成正比关系,factor 1 的载荷分布能有效地反映出溶液浓度与溶液中的 PVC 和环已酮含量的关系.建立了 PVC 溶液浓度的 PLS 回归预测模型,模...     

聚氯代烯烃脱氯化氢的红外光谱研究

用碱脱去聚卤代烯烃中的卤化氢是制备碳炔较为经济简单的方法.本工作分别以聚氯乙烯、聚偏氯乙烯(共聚体)、聚偏氯乙烯(均聚体)为原料,用氢氧化钾脱氯化氢制备碳炔,并利用红外光谱研究各产物中碳炔结构的变化规律,探讨碳炔制备的影响因素,总结得出均聚偏氯乙烯更适合用作制备碳炔的原料.     

仿宝石塑料材料的拉曼光谱分析

应用便携式拉曼光谱仪对赛璐珞、聚苯乙烯、聚氯乙烯、聚甲基丙烯酸甲酯这4种较为常见的仿宝石塑料材料进行了分析测试研究,获得它们的标准拉曼光谱.然后将它们与其对应的被仿宝石(象牙、琥珀、珍珠、水晶)的拉曼光谱分别进行了比对分析.研究结果表明,因其分子结构存在较大差异,其拉曼光谱的差异也比较显著,从拉曼光谱上就能准确地将它们辨别出来.从而找到了一种便捷、准确、快速、无损的鉴定宝石与其塑料仿品的方法.     

采用高分辨电镜分析Cu掺杂聚-4-甲基-1-戊烯泡沫材料采用高分辨电镜分析Cu掺杂聚-4-甲基-1-戊烯泡沫材料

利用物理掺杂的方法,制备了铜掺杂聚-4-甲基-1-戊烯(PMP)低密度泡沫材料,采用高分辨扫描电子显微镜和透射电子显微镜,分析了泡沫材料的微观结构、成分及微区成分分布。结果表明:与PMP泡沫相比,铜掺杂PMP泡沫的孔洞直径和网络骨架尺寸变大;铜颗粒镶嵌在PMP泡沫的有机骨架上且有团聚现象;泡沫材料中除碳、铜外,还残留有杂质元素氧;铜颗粒被PMP泡沫包裹,与碳网络骨架之间接触紧密。     

便携式拉曼光谱仪在毒品和易制毒化学品快速检测中的应用

本文考察便携式拉曼光谱仪对毒品和易制毒化学品的检测识别能力,主要是利用RT3000便携式拉曼光谱仪对甲基安非他命、安眠酮等10种毒品进行测试,以及对黄樟脑、甲苯等10种易制毒化学品进行测试,同时测定白糖、淀粉等白色安全粉末的拉曼谱图。利用专门的建库软件建立以上标准物质的拉曼谱图库,并考察其识别能力。结果显示:此10种毒品和10种易制毒化学品都具有典型的特征拉曼峰,将此毒品和易制毒化学品谱图进行建库,可以对其进行分子层面的准确识别。通过对算法识别的优化以及阈值的调节,便携式拉曼光谱仪所测安全粉末的误报率为0。便携式拉曼光谱仪具有重量轻,便于携带的功能,可为毒品和易制毒化学品的现场快速判别提供一种新的手段,具有良好的应用前景。     

μm量级钨掺杂PMP泡沫制备

以聚-4-甲基-1-戊烯（PMP）为泡沫骨架,m量级钨为掺杂材料,超高分子量聚乙烯（UHWPE）为溶液粘度控制剂,通过热诱导倒相技术实现了低密度钨掺杂聚合物泡沫的制备。实验结果表明:当UHWPE质量分数为25%时,能够实现粒径10 m的钨在泡沫体内的均匀掺杂;泡沫密度为20 mg/cm3时,钨掺杂质量分数最高可达60%。     

多孔PMP聚合物薄膜微结构控制

将二氧化硅(SiO2)微球为模板材料分散在聚-4-甲基-1-戊烯(PMP)溶液中,通过对流自组装方法将其涂覆于基片上,经过热致相分离(TIPS)过程形成含SiO2微球模板的PMP薄膜,然后通过氢氟酸(HF)溶液腐蚀除去SiO2微球,获得了具有规则多孔结构的PMP聚合物薄膜。采用扫描电子显微镜(SEM)对含SiO2微球的PMP薄膜以及除去SiO2微球后的PMP多孔薄膜的微结构进行了表征。研究结果表明:SiO2微球在聚合物中呈有序排列,腐蚀除去SiO2微球后PMP薄膜有效复制了SiO2微球形成的有序结构,形成了有序多孔PMP薄膜。     

掺溴聚-4-甲基-1-戊烯的合成研究

 液溴与聚-4-甲基-1-戊烯（PMP）的四氯化碳溶液反应，在光照条件下得到溴代PMP，通过红外与元素分析确证了其结构。并通过热重分析对其性能进行了初步的研究。研究发现，在光照条件下溴原子很容易与PMP中叔丁基上的氢原子发生取代反应，得到化学掺杂溴原子的聚合物。该聚合物在150℃以下比较稳定，在150℃以上就会失去HBr。采用此种方法，可得到掺杂均匀的低密度材料。     

ICF靶所用掺杂聚合物及泡沫的研制

针对ICF靶所用掺杂聚合物及其泡沫的研制，制备出铜掺杂聚-4-甲基-1-戊烯(PMP)泡沫和掺溴聚合物材料。在掺杂聚合物泡沫过程中采用了超声波振荡的方式，提高了纳米铜粉在PMP泡沫骨架中的分布均匀性。掺杂纳米铜粉CH泡沫已用于今年“神光”Ⅱ试验中，并取得了较好的物理实验结果。利用溴(Br2)和PMP在光照条件下发生的自由基取代反应，制备了部分溴代聚4-甲基-1-戊烯样品。通过控制加入溴的量来控制最终产物中溴的掺杂量。利用红外光谱与元素分析确证样品中溴原子的存在。样品在150℃以前比较稳定，但在150℃以后就会失去溴化氢(HBr)。这对制造靶材料要求的泡沫材料提出了较高的要求。本课题还进行了低密度泡沫铜制备技术和无氰化学镀铁工艺研究。制备得到体积密度约3％的泡沫铜以及化学镀铁样品。     

基于拉曼光谱的PE膜包装食用农产品品质检测误差的校正方法

透明保鲜膜包装以其方便、经济、卫生的特点被广泛应用于超市卖场及日常生活中,却也给食品农产品的检测增加了难度,所以急需一种能够隔透明薄膜无损检测农产品的方法。叶绿素是影响黄瓜品质的重要因素之一,该研究主要探讨了拉曼技术检测黄瓜品质时,食品保鲜膜层数对叶绿素特征峰的影响,并通过对菠菜、油菜和芹菜对得出的结论进行验证。采用点检测拉曼光谱系统,采集无保鲜膜包装以及多层包装下黄瓜的拉曼光谱。拉曼信号经Savitzky-Golay(SG) 5点平滑和自适应迭代惩罚最小二乘法扣除荧光背景,探究不同层数(1~6层)的PE保鲜膜对黄瓜叶绿素特征峰的影响。采集被保鲜膜覆盖的黄瓜的拉曼信号并处理,即可建立叶绿素的特征峰(1 158和1 528 cm-1)减少值与保鲜膜层数之间的变化规律,并对规律的预测效果进行评价。随着保鲜膜层数的增加,透明包装层数与黄瓜叶绿素特征峰强度之间呈现良好的线性相关关系。提取出单层透明包装对叶绿素在1 158和1 528 cm-1处特征峰强度的降低值分别为81.4和103.1,分别占未加保鲜膜时叶绿素特征峰强度值的7.98%和8.56%,多组验证结果的相关系数达到0.95以上,验证的相关系数达到0.94。随着样品浓度增高,线性递减效果越明显。作为验证,通过透明保鲜膜检测菠菜、油菜和芹菜叶片中的叶绿素表明,每加一层膜叶绿素在1 158和1 528 cm-1处的特征峰强度会比覆膜前分别降低7.9%～8.6%和8.1%～8.6%;导致检测信号强度呈线性降低是由于保鲜膜使激发光分散不聚焦导致,保鲜膜成分对检测结果无影响。该研究为拉曼光谱隔透明包装检测拉曼光谱特征峰强度,进而获得农产品品质信息提供了一种新的分析方法。     

Catalytic cracking of tar derived from the pyrolysis of municipal solid waste fractions over biochar

The tars derived from the pyrolysis of four typical municipal solid waste fractions at 600 °C, namely pine wood (PW), tryptone (TP), polyethylene (PE) and polyvinyl chloride (PVC), were characterized and then catalytically cracked by activated biochar catalyst (ABC) at 700–900 °C. The ABC was produced from the pyrolysis of pine wood at 800 °C for 1 h, then activated by CO₂ at 900 °C for 20?min. The results showed that O-containing species, N-containing species, chain hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were the main products in the raw tar from the pyrolysis of PW, TP, PE and PVC, respectively. The tar cracking efficiency by ABC was ordered as PW>TP>PE>PVC, which indicated that the biomass tars were easier to be converted by ABC than plastic tars. The highest tar conversion of 98.7% was achieved for PW at 900 °C. Besides, N-containing tars were more stable than O-containing tars. The coke deposition on the ABC was more serious after the cracking of plastic tars (PE and PVC) than that of biomass tars (PW and TP). After the catalytic cracking of TP and PVC tars at 900 °C, the nitrogen and chlorine contents in ABC increased by 3 times and 10.5 times, respectively.     

塑料挥发物长光程FTIR测量方法

塑料产品除了在自然环境中可降解为微塑料污染环境之外,还会产生挥发性有机物,同样对环境造成巨大的污染和危害,因此对塑料挥发物的测量就显得尤为重要。目前传统挥发物的测量方法,如环境质谱法和色谱法等,存在测量过程复杂,成本高,无法实时测量等缺点,因而需要一种快速有效的针对塑料挥发物的测量方法。采用傅里叶变换红外光谱仪（Fourier transform infrared spectrometer,FTIR Spectrometer）结合怀特池对塑料挥发物进行测量,但是由于抽取式傅里叶变换红外光谱仪本身灵敏度有限,很难实现微量的塑料挥发物的测量,所以针对这一问题,尝试通过长光程气体池提高常规傅里叶变换红外光谱仪的灵敏度从而实现不同种类塑料挥发物的测量。选取了5种塑料产品,分别是低密度聚乙烯（LDPE）,高密度聚乙烯（HDPE）,聚乙烯（PE）,聚对苯二甲酸乙二醇酯（PET）,聚丙烯（PP）,利用光程长为20 m的怀特池结合傅里叶变换红外光谱仪实现了其中一些挥发物的光谱特征观测,实验观察到所有种类的塑料在2个光谱波数段具有明显的光谱特征,分别为800~850和1 050~1 150 cm-1。除聚对苯二甲酸乙二醇酯（PET）外,其余4种塑料挥发物在2 800~3 000 cm-1还存在明显的光谱吸收波段。进一步又研究了不同温度条件下塑料产生的挥发物,通过分析不同温度条件下的塑料产生的挥发物的红外光谱,发现除低密度聚乙烯（LDPE）在两种温度条件下光谱差异较大外,其他种类的塑料挥发物红外光谱差异较小。该研究提出了一种新型的基于长光程FTIR的塑料挥发物的测量方法,证实了其在塑料挥发物测量方面的有效性,这种方法具有测量成本低,可连续观测,实时在线等优点,为实现连续在线的塑料挥发物排放通量监测奠定了基础。     

Selected polymers on CW and pulsed THz investigations

The paper gives the results of refractive indexes for three plastic materials: polyethylene, polymethyl methacrylate and polyvinyl chloride, which are measured and compared in two arrangements - a CW THz photomixer and a pulsed THz spectrometer.     

REFLECTIVE INFRARED ELLIPSOMETRY OF PLASTIC FILMS

High resolution reflective ellipsometry is used to study freely suspended plastic films. We determine room temperature optical constants in the infrared for a variety of plastics using ellipsometry. The films are typically 6 to 100 μm thick and measurements are performed from near infrared to long wave-IR. The setup includes modeling software to fit the ellipsometric data to a generalized oscillator model. The films studied include acrylics, fluoropolymers, and variations of polyethylene, polystyrene, and polyvinyl chloride (PVC) among others. We are able to determine in-plane and out-of-plane optical constants. Transmission spectra from FTIR measurements are plotted and compared with ellipsometry results.     

几种塑料的太赫兹光谱检测

利用太赫兹时域光谱技术测量了聚乙烯、聚丙烯、聚氯乙烯、聚四氟乙烯和丙烯腈-丁二烯-苯乙烯的太赫兹透射谱,研究其在0.2~2.6 THz频段的光谱特性,得到了在室温氮气环境下这些材料的太赫兹吸收谱和折射率色散特性.发现这五种塑料在太赫兹波段的折射率和吸收系数差异显著,折射率分别在1.35~1.85之间,聚乙烯、聚丙烯、聚四氟乙烯吸收很小,相比之下聚氯乙烯、丙烯腈-丁二烯-苯乙烯吸收很大,这为塑料种类的鉴别及高太赫兹透过率塑料衬底选择提供了依据.     

Diffusion of 1,2,3-Benzotriazole as a Volatile Corrosion Inhibitor through Common Polymer Films Using the Molecular Dynamics Simulation Method

Diffusion of 1,2,3-benzotriazole (BT), as one of the volatile corrosion inhibitors (VCI) for copper and steel, through several polymers was investigated using molecular dynamics simulation (MD). MD were performed by employing the COMPASS force field to estimate the diffusivity of BT through polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), and Nylon 6 as potential hosts for anticorrosion film packaging purposes. The diffusion coefficients (D) of BT in these polymers were calculated by constructing an amorphous cell, each containing BT and one of these polymers. After constructing the cell, a molecular dynamics simulation was performed to calculate the mean square displacement of the BT molecule. Simulation results showed that BT can diffuse through PVC easier than the other polymers. Among these hosts the Nylon 6 had the lowest D value, implying that this polymer can maintain BT for a long time. The temperature dependence of diffusion through PE, as the most common VCI film, was studied and the activation energy (Q_d) and pre-exponential diffusion coefficient (D₀) in Arrhenius equation were calculated.     

Preparation of porous super-hydrophobic and super-oleophilic polyvinyl chloride surface with corrosion resistance property

Porous super-hydrophobic polyvinyl chloride (PVC) surfaces were obtained via a facile solvent/non-solvent coating process without introducing compounds with low surface energy. The microstructure, wetting behavior, and corrosion resistance of resultant super-hydrophobic PVC coatings were investigated in relation to the effects of dosage of glacial acetic acid and the temperature of drying the mixed PVC solution spread over glass slide substrate. As-prepared PVC coatings had porous microstructure, and the one obtained at a glacial acetic acid to tetrahydrofuran volume ratio of 2.5:10.0 and under a drying temperature of 17 °C had a water contact angle of 150 ± 1.5°, showing super-hydrophobicity. In the meantime, it possessed very small contact angles for liquid paraffin and diiodomethane and good corrosion resistance against acid and alkali corrosive mediums, showing promising applications in self-cleaning, waterproof for outer wall of building, seawater resistant coating, and efficient separation of oil and water.     

Determination of solid material elastic modulus and surface energy based on JKR contact model

The JKR contact theory is employed to study the adhesion phenomena between two solid materials in intimate contact. The elastic contact modulus and the work of adhesion of solid materials are obtained during adhesion tests by utilizing a micro force-deflection measuring apparatus. Six of the plastic materials, including polyethylene polyoxymethlene (POM), polyamide (PA), terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), and ultra-high molecular weight polyethylene (UHMWPE) are used to evaluate the adhesion effect implied by the JKR theory. Comparison is made between surface energy obtained from the adhesion tests with that by a dynamic contact angle analyser.Results show that the load/deflection data in the loading phase are in good agreement with the predictions of JKR equation, and the experimental data of unloading phase deviate significantly from the JKR theory. The phenomena of adhesion hysteresis in loading tests are responsible for these results due to the effects of molecular reconstruction on solid surfaces in contact. The work of adhesions, and hence surface energies of plastic materials, calculated by the best fitting of JKR equation with the experimental data in the loading phase, agree satisfactorily in a comparable manner with that obtained using the contact angle analyser.