离子液体添加剂对硬脂酸钾固体润滑薄膜摩擦磨损性能的影响

采用浸渍-提拉方法在单晶硅片上制备硬脂酸钾以及添加离子液体的硬脂酸钾复合薄膜,采用DF-PM型静-动摩擦磨损试验机考察薄膜在低速滑动条件下的摩擦磨损性能,采用扫描电子显微镜和X射线能量散射谱仪观察分析薄膜及其偶件表面的磨损形貌及典型元素面分布.结果表明:在相对低速滑动条件下,在羟基化硅基底上制备的复合薄膜的摩擦磨损性能优于硬脂酸钾薄膜;在载荷为1.0 N条件下,含离子液体质量分数40.0%的复合薄膜的耐磨寿命超过5 000次,而硬脂酸钾薄膜仅为100次左右;随着复合薄膜中离子液体含量增加,复合薄膜更容易在偶件钢球表面形成有效转移薄膜,使复合薄膜摩擦磨损性能得以提高.     

The Effect of Volume Reorganization of Amorphous Poly(ethylene Terephthaiate) on Thermal Properties

When poly(ethylene terephthalate) was quenched from above T_g and then heated, it exhibited a step increase in thickness in the glass transition region at every rate tested. When the polymer was cooled more slowly than it was heated, a higher T_g and a slightly larger step increase in thickness were observed as the cooling rate was reduced. These experimental results appear to be adequately interpreted on the basis of the normal structural changes that occur in a glass as its thermal history is varied. Two observations, however, were not easily included in this view. First, the polymer, on cooling from above T_g, exhibited an abnormally high expansion coefficient over much of the range of temperature in which it exists as a fluid. Second, the polymer exhibited a step increase in thickness when it was heated at the same rate at which it had previously been cooled.     

Poly(3,5‐dichloroaniline) Doped with Different Sulfonic Acids

Poly(3,5‐dichloroaniline) was prepared by chemical oxidation in the presence of various sulfonic acids as doping agent, using potassium permanganate as oxidant. 1‐Naphtalene sulfonic acid, 2‐naphatalene sulphonic acid, 1,5‐naphtalene disulfonic acid, and p‐toluenesulfonic acid were the acids of choice. Infrared and UV‐Vis spectroscopy, utilized to characterize the polymers, revealed that the compounds exist in the emeraldine (conductive) oxidation state. The level of doping, conductivity, and morphology were determined as well. The presence of a sulfonic acid produces a morphological change, from granular to microtubule structures, which is responsible for the strong increase in the conductivity of the polymer.     

Grafting of 4‐Vinyl Pyridine onto Nylon‐6 Initiated by Cu(III)

In this article, the graft copolymerization of 4‐vinyl pyridine (4VP) onto nylon‐6 (PA6) using potassium diperiodacuprate (III) (DPC)–PA6 redox system as initiator is investigated in an alkaline medium. The structure and the properties of graft copolymer are confirmed by Fourier transfer infrared spectroscopy (IR), X‐ray diffraction and thermogravimetric analysis (TGA). The mechanism is proposed to explain the generation of radicals and the initiation. The effects of reaction variables, such as the initiator concentration, ratio of 4VP to PA6, pH, as well as reaction temperature and time are investigated. Graft copolymers with high grafting efficiency (>95%) were obtained, which indicated that the DPC–PA6 redox system was an efficient initiator for this graft copolymerization. The quaternized PA6‐g‐P4VP (QPAVP) is proven to be an excellent adsorbent to heavy metal ions.     

大口径氘化磷酸二氢钾晶体离线亚纳秒激光预处理技术

大口径氘化磷酸二氢钾(DKDP)晶体抗激光损伤性能偏低严重地制约着大型高功率激光装置输出水平.本研究利用离线亚纳秒激光预处理技术有效地提升了大口径DKDP晶体抗激光损伤性能.实际使用情况表明,采用离线亚纳秒激光预处理后,DKDP晶体在9 J/cm²激光通量辐照下的表面平均损伤密度得到大幅下降,由未处理前的5.02 pp/cm²(1pp表示1个百分点)降至0.55 pp/cm²,降幅为一个数量级.同时,激光预处理对晶体损伤尺寸具有一定的抑制作用,预处理后晶体损伤点尺寸分布曲线向尺寸减小的方向平移,尺寸分布峰值由预处理前的25μm降至预处理后的18—20μm.     

修饰铂电极-示波双电位滴定法测定Zn(Ⅱ)

制备了锌修饰铂电极,建立了一种新的测定Zn(Ⅱ)的示波双电位滴定法。在六次甲基四胺溶液(1.0mol/L)中(pH=5.5),用制备的修饰铂电极作为双指示电极,以EDTA标准溶液滴定Zn(Ⅱ),利用示波器屏幕上荧光点的显著最大位移指示滴定终点。在3.0×10-4～2.0×10-3mol/L的浓度范围内,Zn(Ⅱ)的回收率为99.9%～100.2%。该修饰电极具有良好的稳定性和重现性,对Zn(Ⅱ,1.0×10-3mol/L)溶液连续11次测定,所得终点电位值均在10.1mV左右,其相对标准偏差(RSD)为0.5%。用来测定含锌的实际样品,其结果与指示剂法测定的值基本一致。     

自动电位滴定法测定冷轧薄板酸洗液中总酸度

自动电位滴定法测定酸液中总酸度具有简单、快捷、不受其他元素干扰等优点。用硫代硫酸钠掩蔽铁离子,利用自动电位滴定仪测定冷轧薄板酸洗液的总酸度(以盐酸量计)。当电位突变达30mV以上时,仪器自动判定滴定终点。自动电位滴定法测定冷轧薄板酸洗液中总酸度结果与酸碱中和滴定方法具有较好的一致性。相对标准偏差小于0.6%,能够满足生产检验的要求。     

基于吸收系数的生脉注射液中聚山梨酯80含量测定新方法

聚山梨酯80又名吐温80，为一种亲水型非离子表面活性剂，是食品、保健品和药品中常用的辅料，作为增溶剂和澄清剂广泛用于中药注射剂。近年来，不良反应的发生使得聚山梨酯80的质量和应用愈加受到重视，有研究认为其加入可能引起注射剂不良反应增加。为避免超量使用，有必要对该辅料的投料加以严格控制。中药注射剂中聚山梨酯80的含量测定是当下研究的热点和难点，可以通过分光光度法、分子排阻-蒸发光散射检测法(SEC-ELSD)、液质联用法(LC-MS)直接测定，也可以水解后法经液相色谱-紫外检测法(HPLC-UV)或气相色谱法(GC)间接测定。但由于聚山梨酯80为聚氧乙烯聚合数目不同的混合物、不同厂家生产的聚山梨酯80化学组分及比例存在较大差异，难以采用统一的转换公式或对照品准确定量。此外，中药注射剂的复杂基质造成的假阳性干扰也对定量提出了挑战。为解决以上问题，以生脉注射液为例，提出基于吸收系数的中药注射剂中聚山梨酯80含量测定新方法。优化检测波长、显色剂种类、液液萃取过程振荡和静置时间，在6个不同品牌仪器上测得聚山梨酯80-硫氰酸钴配合物的吸收系数(E1%_{1 cm})为104.23，相对标准偏差(RSD)为2.08%。生脉注射液稀释10倍后，精密量取供试品溶液1.0 mL，精密加入硫氰酸钴溶液10 mL，二氯甲烷20 mL，涡旋振荡3 min。将混合液移至分液漏斗中，静置30 min，取下层二氯甲烷液，将前1 mL弃去，接收约15 mL，在320 nm处测定吸光度，再根据Lambert-Beer定律，利用获得的吸收系数计算得到聚山梨酯80的含量。方法阴性无干扰，精密度和重复性相对标准偏差均低于3%，平均回收率为98.42%。为进一步验证方法的准确性，分别采用吸收系数法和标准曲线法测定了2个厂家的10批生脉注射液，并与实际投料量比较。配对t检验结果表明，当置信度为95%时，两种方法无显著性差异，吸收系数法测得结果与企业生产中聚山梨酯的实际投料量也无显著性差异。研究采用前人未采用的、灵敏度更高的320 nm为检测波长，显著降低了基质干扰，克服了中药注射剂中聚山梨酯80测定结果与实际投料量难以吻合的问题。吸收系数法无需使用对照品，亦不用制备标准曲线，可为中药注射剂中聚山梨酯80的检查标准提供切实可行的解决方案。所建方法灵敏、准确、快速、简便，为含聚山梨酯80制剂的质量控制提供了关键常数及新的思路。     

Low-Valent Group 14 NHC-Stabilized Phosphinidenide ate Complexes and NHC-Stabilized K/P-Clusters

The N-heterocyclic carbene (NHC)-stabilized phosphinidenide, SIMesPK [SIMes=1,3-bis(2,4,6-trimethylphenyl)imidazolidine-2-ylidene], was used as an (NHC)P-transfer reagent for the synthesis of the low-valent Group 14 ate complexes K[(SIMesP)₃E] (E=Ge: 2 , Sn: 3 , Pb: 4 ), which were characterized by ¹H NMR, ³¹P NMR, IR spectroscopy as well as elemental and X-ray analysis. Furthermore, SIMesPK was used in reactions with potassium amides and alkoxides to form the molecular phosphorus–potassium clusters [K₄(SIMesP)₂(hmds)₂] [ 5 , hmds=N(SiMe₃)₂] and [K₆(SIMesP)₂(OtBu)₄] ( 6 ). Finally, the reaction of SIMesPK with Li[Al(OC₄F₉)₄] led to the potassium-rich ionic compound [(SIMesP)₄K₅][Al(OC₄F₉)₄] ( 7 ).     

Experimental Evaluation of the Additive Compounds Performance on Asphaltene Precipitation Using Automatic Titration Method

The use of soluble amphiphiles oil types provide the most practical and economical solution for crude oil treatment in order to control the asphaltene precipitation phenomenon. In this article, the inhibition performance of a number of new chemical additives to asphaltene precipitation is examined on two types of Iranian crude oil. An automatic titration method is used in experimental evaluation. The vegetable oil types (hazelnut, wheat germ, and walnut), organic acids (oleic and linoleic) and chemical additives (4-dodecylresorcinol and benzyl alcohol) displayed the highest capacity to inhibit asphaltene precipitation. A remarkable onset displacement is displayed by dodecyl resorcinol. The results also revealed that the vegetable oil have high potential in delaying asphaltene precipitation.