碱溶性有机硅疏水缔合增稠剂的合成及应用

以自制有机硅单体为疏水功能单体,采用乳液聚合反应合成一种有机硅链段疏水缔合的碱溶性增稠剂,并考察其在染料印花中的应用效果。研究了功能单体用量、中和碱、pH值、增稠剂用量等因素对增稠剂性能的影响,对比了碱溶性增稠剂和市售普通染料增稠剂的性能差异。结果表明:功能单体质量分数为4%～5%,以氢氧化钠为中和碱,pH=10～12时,碱溶性增稠剂的增稠性能最佳;相比市售染料增稠剂,碱溶性有机硅疏水缔合增稠剂在印花浆黏度、流变性、耐电解质能力、洗脱性和印花效果方面优势明显。     

高浓度活性染料溶液中分子聚集状态的分子模拟

对不同浓度活性染料在水溶液中的聚集状态进行了分子动力学模拟研究。通过分析溶液中染料分子的均方根偏差(RMSD)、均方位移(MSD)和溶剂可及表面积(SASA),从宏观上确定染液浓度对染料分子聚集的影响;通过分析溶液中染料分子中C原子的径向分布函数(RDF),定义判断染料分子间发生聚集的通用性标准,进而从微观状态解释造成宏观现象的本质。结果表明:当浓度较低时,染液中染料单体的个数较多,随着染液中染料浓度的增加,染料分子间的聚集程度增大,系统中存在多种聚集体的平衡,但仍有稳定存在的染料单体。染料分子间多以平面堆叠排列的形式存在。     

高效液相色谱法测定烟叶中的总茄尼醇

为了简化烟叶样品前处理步骤,采用正己烷直接萃取烟叶样品得到烟叶的正己烷萃取液,利用KOH水溶液对正己烷萃取液直接进行油水两相皂化,再采用高效液相色谱法测定皂化后萃取液中的茄尼醇浓度.结果表明:①萃取温度65°C,萃取时间24 h,KOH水溶液浓度0.01 mol/L,皂化时间0.5 h时,萃取效率较好,皂化转化率较高;②茄尼醇的质量浓度范围为2.125～34.000 mg/L时,峰面积与质量浓度具有良好的线性关系,相关系数为0.99998;③平均回收率为97.6%,相对标准偏差(RSD)为2.7%(n=3).表明该方法快速、简便、准确.     

预聚体中亲水基位置与水性聚氨酯乳液性能

通过改变单体的摩尔比率及合成方案使二羟甲基丙酸(DMPA)位于预聚体不同位置,并乳化分散为水性聚氨酯(PUD),对乳液的分散性(采用激光粒度仪)、稳定性以及固含量进行分析。结果表明:DMPA未与长疏水链(低聚物二元醇、异氟尔酮二异氰酸酯及1,4丁二醇反应形成的)连接在合成PUD分散效果最差、乳液不稳定;DMPA位于两低聚物二元醇分子之间产生的分散效果稍好,但使乳液粒子产生较大的溶胀;而DMPA靠近预聚体分子端末且与长疏水链连接在一起则产生良好乳化效果,获得更小的粒径分布、可减少合成PUD所需DMPA用量并使乳液固含量达到50%以上。并发现合成方案对胶膜性能亦有一定的影响。     

异养小球藻油脂正己烷提取工艺优化

为确定最佳异养小球藻油脂正己烷提取工艺,对提取工艺中的关键参数如藻细胞溶液质量浓度、破碎压力、破碎次数、萃取时间、萃取温度、萃取剂正己烷添加量对油脂得率的影响进行了研究。结果表明,最佳油脂提取工艺条件为藻细胞溶液质量浓度110 g/L、破碎压力100 MPa、破碎次数4次、萃取时间5 h、萃取温度40℃、正己烷添加量9 m L/g(以藻粉干重计),在该条件下萃取5次,油脂得率最高,可以达到55%左右。     

烯唑醇分子印迹固相萃取膜的制备及其应用

以烯唑醇为模板分子,丙烯酰胺(AM)为功能单体,采用原位聚合法制备出对烯唑醇具有高选择性的分子印迹固相萃取膜;通过紫外光谱试验优化了功能单体,考察了不同功能单体与模板分子的结合能力,同时考察了制备印迹膜时致孔剂的选择和分子印迹膜印迹次数对液体通过性的影响;建立了基于分子印迹固相萃取膜-高效液相色谱法测定粮谷中烯唑醇残留的方法。结果表明,与功能单体α-甲基丙烯酸(MAA)相比,丙烯酰胺(AM)与烯唑醇的结合能力更强,以乙腈为制孔剂制备烯唑醇印迹膜,印迹一次印迹膜较稳定,且液体通透性良好。烯唑醇在0.5~15μg/m L浓度范围内有良好的线性关系(r=0.9987),平均回收率在80.34%~87.03%之间,检出限为2.0μg/g。该方法选择性强、灵敏、可靠,适用于粮谷等复杂基质中烯唑醇的残留检测。     

GC-MS内标法同时测定鞋材中邻苯基苯酚和含氯苯酚残留量

通过优化样品萃取条件、衍生化条件和色谱分析条件,建立了GC-MS法同时测定鞋材中邻苯基苯酚和含氯苯酚残留量的方法。采用1 mol/L KOH溶液为溶剂,超声辅助萃取鞋材中酚类化合物,滤液经乙酸酐衍生化、正己烷萃取后,供气相色谱-质谱确证和测定,内标法定量。结果表明：该方法简便快捷、回收率稳定,灵敏度高、重现性好,在0.05～1.00 mg/kg的含量范围内,线性相关系数均大于0.998 7,在3个不同添加浓度水平下,方法的平均加标回收率为84.63%～115.61%,相对标准偏差为1.09%～4.05%,检出限为0.05 mg/kg,可满足进出口鞋材中20种酚类物质同时检测需求。     

过硫酸钾-亚硫酸氢钠氧化还原引发体系中丙烯酰胺聚合动力学的研究

探讨了过硫酸钾—亚硫酸氢钠组成的氧化还原引发体系在水溶性单体丙烯酰胺溶液聚合中的引发作用,观察到在相同聚合条件下,不同引发剂用量和不同亚硫酸氢钠与过硫酸钾摩尔比时,丙烯酰胺单体转化率、聚合反应速率和聚丙烯酰胺分子量有明显差异。实验结果表明:引发剂用量为0.20%时,AM单体转化率较高,达到95%;引发剂用量为0.15%时,聚丙烯酰胺的分子量较大,为158万;亚硫酸氢钠与过硫酸钾的摩尔比为0.6时,转化率和聚合速率最大;反应速率与引发剂浓度的指数为0.53,与自由基聚合双基终止条件下的理论值0.5接近。     

LiCl/DMAc溶剂体系中疏水改性羟乙基纤维素的合成

本文采用大分子反应法,将疏水性单体溴代十二烷(BD)接枝到羟乙基纤维素(HEC)上,对羟乙基纤维素进行疏水改性,制备了疏水改性羟乙基纤维素(HMHEC)。在LiCl/DMAc溶剂体系中,研究了催化剂用量、溶胀温度和LiCl浓度对HMHEC性能的影响,最佳合成工艺条件为:溶胀温度为150℃,催化剂KMnO4用量为0.02%,LiCl浓度为9%,反应温度为80℃,反应时间为7h,m(BD)/m(HEC)为0.4。在LiCl/DMAc体系中合成的HMHEC的黏均分子量为3.31×107,临界缔合浓度在0.4g/100mL左右。     

LC-MS/MS法快速筛查辣椒制品中8种禁用苏丹染料

建立辣椒制品中8种禁用苏丹染料(苏丹红Ⅰ、苏丹红Ⅱ、苏丹红Ⅲ、苏丹红Ⅳ、苏丹红7B、苏丹红G、苏丹蓝Ⅱ、苏丹黄)的液相色谱-串联质谱法快速筛查方法。辣椒制品经正己烷萃取,氧化铝柱净化,用乙腈和0.1%甲酸水溶液作为流动相,经C18色谱柱梯度洗脱分离,质谱仪定性定量。结果表明:8种苏丹染料在2.5 ng/mL～500.0 ng/mL质量浓度范围内,呈现良好的线性关系,相关系数r2≥0.999 5;检出限为0.62 ng/mL～6.25 ng/mL,测定下限为2.5 ng/mL～25.0 ng/mL;平均回收率在92.4%～98.6%之间,RSD在1.7%～3.8%之间。液相色谱-串联质谱(liquid chromatographtandem mass spectrometry,LC-MS/MS)法适用于快速筛查复杂基质辣椒制品中8种禁用苏丹染料。     

染色涤纶低聚物的控制

涤纶低聚物是单体在缩聚反应过程中形成的低分子质量副产物。据美国纺织品生产商宣称,远东地区出产的涤纶纤维中的低聚物含量可能高达10%。低聚物是影响涤纶染色的大问题,目前还没有有效的解决方法。根据国内外有关染色涤纶低聚物的研究,从低聚物的形成及影响入手,总结了目前控制染色涤纶低聚物的主要方法,包括低温染色、碱性染色、添加助剂、高温排液、染色后处理以及生物酶处理,以有效控制涤纶染色中低聚物的不良影响,从而为解决染色涤纶低聚物问题提供一定的参考。需要指出的是,控制涤纶聚合环节中低聚物的生成是解决低聚物问题最根本和有效的方法,应该引起重视。     

Characterization and encapsulation efficiency of rhamnolipid vesicles with cholesterol addition

The effect of cholesterol on the vesicle formation of a rhamnolipid biosurfactant extracted from the liquid culture of Pseudomonas aeruginosa SP4 was investigated. The rhamnolipid vesicles were prepared in a phosphate-buffer saline (PBS) solution (pH 7.4) at a biosurfactant concentration of 2.6mM, or 6.5 times the critical micelle concentration (CMC), with various amounts of cholesterol. The biosurfactant solution was characterized using turbidity, zeta potential, and dynamic light scattering (DLS) measurements. The morphology of the rhamnolipid vesicles formed at different cholesterol concentrations was examined with the use of transmission electron microscopy (TEM). The results showed that the rhamnolipid biosurfactant formed spherical vesicles both in the absence and presence of cholesterol, but the incorporation of the cholesterol into the bilayer membrane reduced the vesicle size. Sudan III, a water-insoluble dye, was used as a model hydrophobic compound in the encapsulation experiment. The encapsulation efficiency (E%) of the rhamnolipid vesicles was affected by the cholesterol concentration and the initial Sudan III concentration. The maximum E% of nearly 90% was achieved at the cholesterol concentration of 100μM and the initial Sudan III concentration of 8.8μM.     

Molecular size evolution of oligomers in organic aerosols collected in urban atmospheres and generated in a smog chamber

Only a minor fraction of the total organic aerosol mass can be resolved on a molecular level. High molecular weight compounds in organic aerosols have recently gained much attention because this class of compound potentially explains a major fraction of the unexplained organic aerosol mass. These compounds have been identified with different mass spectrometric methods, and compounds with molecular masses up to 1000 Da are found in secondary organic aerosols (SOA) generated from aromatic and terpene precursors in smog chamber experiments. Here, we apply matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) to SOA particles from two biogenic precursors, alpha-pinene and isoprene. Similar oligomer patterns are found in these two SOA systems, but also in SOA from trimethylbenzene, an anthropogenic SOA precursor. However, different maxima molecular sizes were measured for these three SOA systems. While oligomers in alpha-pinene and isoprene have sizes mostly below 600-700 Da, they grow up to about 1000 Da in trimethylbenzene-SOA. The final molecular size of the oligomers is reached early during the particle aging process, whereas other particle properties related to aging, such as the overall acid concentration or the oligomer concentration, increase continuously over a much longer time scale. This kinetic behavior of the oligomer molecular size growth can be explained by a chain growth kinetic regime. Similar oligomer mass patterns were measured in aqueous extracts of ambient aerosol samples (measured with the same technique). Distinct differences between summer and winter were observed. In summer a few single mass peaks were measured with much higher intensity than in winter, pointing to a possible difference in the formation processes of these compounds in winter and summer.     

Preparation of chitosan oligomers and their antioxidant activity

Chitosan oligomers with different molecular weights were prepared by oxidative degradation method involving hydrogen peroxide (H₂O₂) and the combined degradation method using hydrogen peroxide and microwave radiation. Viscosity determination and end group analysis were applied to measure molecular weights of chitosan oligomers. Effects of concentration of H₂O₂ and degradation time on molecular weights of chitosan oligomers were studied. Both methods were effective to prepare chitosan oligomers from the initial chitosan (8.5×10⁵ Da). The degradation process of chitosan will be accelerated with the aid of microwave and degradation time may be reduced. The antioxidant activity of chitosan oligomers was evaluated as radical scavengers against superoxide anion and hydroxyl radical by application of flow injection chemiluminescence technology. Chitosan oligomers A, B, C and D (2300, 3270, 6120, and 15,250 Da) had different antioxidant activity. Among the four chitosan oligomers, oligomer D (15,250 Da) had the lowest scavenging ability against superoxide anion and hydroxyl radicals. For superoxide anion scavenging, the 50% inhibition concentrations (IC₅₀s) of other three oligomers A, B, and C were 5.54, 8.11, and 12.15 mg/mL, respectively. And for hydroxyl radical scavenging the values were 0.4, 0.76, and 1.54 mg/mL, respectively. At the concentration range examined, the maximal inhibiting efficacy of A, B, C, and D were 89, 75, 74, and 41% for superoxide anion, and 71, 65, 51, and 7% for hydroxyl radical. These results indicated that chitosan oligomers with lower molecular weight had better antioxidant activity.     

利用3-噻吩丙二酸修饰玻碳电极快速检测苏丹红

利用电化学聚合法制备3- 噻吩丙二酸(3-TPA)修饰玻碳电极。利用循环伏安法研究苏丹红在3-TPA 修饰玻碳电极上的电化学行为,得出预富集时间、pH 值、扫描速率及扫描范围因素对该修饰电极检测苏丹红的影响。在最佳条件下,利用差分脉冲伏安法得出在2.0 × 10-5～1.3 × 10-3mol/L 浓度范围内苏丹红Ⅰ响应电流与其浓度对数呈良好的线性关系,相关系数r=0.996,检测限为4.8 × 10-6mol/L。辣椒粉、辣椒酱加标回收率分别为99.9% 和99.4%,相对标准偏差(n=3)分别为0.25% 和0.21%。另外,对苏丹红Ⅰ氧化还原机理进行了初步的探讨。     

固相萃取-液质联用测定辣椒粉中苏丹红

该试验建立了分子印迹固相萃取-超高效液相色谱-串联质谱法检测辣椒粉中苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ的方法。辣椒粉样品经过正己烷提取,氮吹浓缩,苏丹红专用分子印迹固相萃取柱净化和富集,以体积分数为0.2%的甲酸水溶液和乙腈为流动相梯度洗脱,经Agilent ZORBAX Eclipse Plus C₁₈(2.1 mm×50 mm,1.8μm)柱分离,ESI+电喷雾模式扫描,MRM多反应模式监测,外标法定量。结果显示,该方法下4种苏丹红的检出限均为5μg/kg,4种化合物在0~50μg/L质量浓度范围内线性关系良好,相关系数均在0.9990以上;当加标浓度为10,50和100μg/kg时,回收率在86.5%~102.2%之间,相对标准偏差均小于6.0%。该方法可为辣椒粉中4种苏丹红的定性定量分析提供参考。     

生物基聚对苯二甲酸丙二醇酯低聚物的提取及其热性能

针对目前生物基聚对苯二甲酸丙二醇酯(PTT)产业化过程中,大量环状低聚物的形成易对后续加工造成不良影响的问题,通过索氏提取法和溶解沉淀法对生物基PTT切片、纤维及粉末样品中提取的环状低聚物进行表征与分析。结果表明:从PTT纤维中提取的环状低聚物的质量分数为3.6%,比PTT切片中的高约1%;低聚物的主要组分为环状二聚体,其质量分数约占低聚物总量的85%~90%;同时检测出低质量分数的环状三聚体、环状四聚体、环状五聚体及环状七聚体,几种组分占低聚物总量的10%~15%;环状低聚物的热稳定性远低于生物基PTT高聚物且具有比高聚物更高的熔融温度,可充当成核剂,促进高聚物的结晶。     

基于适配体-阳离子化合物诱导纳米金聚集比色法快速检测苏丹红

本研究以苏丹红Ⅲ适配体为识别元件,以未修饰的纳米金传感信号,以聚二烯丙基二甲基氯化铵(PDDA)作为纳米金聚集的诱导剂,构建了一种简单、经济、快速的苏丹红比色检测方法。在优化条件下评估本方法的检测灵敏度、准确性和特异性,最后应用于食品中苏丹红快速检测,并将检测结果与国标法(GB/T 19681-2005)对比验证。结果显示,在PDDA浓度20 nmol/L、适配体浓度5 nmol/L、反应时间4 min等优化条件下,纳米金吸光度比值(A_650nm/A_530nm)与苏丹红Ⅲ浓度呈良好线性关系(R=0.986),线性检测范围为3.13～50 ng/mL,可视化检测限为3.13 ng/mL,检测时间约为5 min。特异性分析显示,本方法对苏丹红Ⅰ、Ⅱ、Ⅲ和Ⅳ有高的特异性,与柠檬黄、日落黄、分散橙11等无交叉反应。将本方法应用于食品中苏丹红检测,加标回收率为85.4%～102.5%,相对标准偏差为3.37%～6.75%。本方法具有操作简便、快速、结果易读等优点,适用于批量样品中苏丹红的现场快速检测。     

The behaviour of cationic cellulose derivatives containing fatty quat groups

The use of trimethyl quat cellulose derivatives in hair and skin care products is well established. The introduction of fatty quat groups into cellulose can modify the surface activity and conditioning behaviour. The present study was directed to a coconyl dimethyl quat derivative of cellulose, with an average molecular weight of approximately 100,000. A modified version of the rubine dye test, capable of giving quantitative results, was used to seek information on substantivity and tendency for build-up on hair. The evidence presented indicates that this surface-active cellulose polymer exhibits a plateau maximum value for substantivity which is achieved by a single conditioning treatment as an aqueous solution with a concentration of 1% or higher. The same plateau value can be approached by successive shampoo/conditioning cycles at lower polymer concentrations. This in-built mechanism for preventing excessive build-up from aqueous solutions is compared with the behaviour of other cationic cellulose polymers of higher average molecular weight.     

超声波/碱处理去除PTT纤维染色中的表面低聚物

采用超声波／碱协同处理工艺对PTT聚酯纤维进行染色前预处理，探讨了不同处理条件对染色后纤维表面低聚物的去除效果，以及对染料上染率和表观颜色深度的影响，并由此优化给出最佳处理工艺条件。结果表明，超声波／碱协同处理能有效地解决PTT聚酯纤维染色中的低聚物问题，且上染率和表观颜色深度也有所提高。