聚甲基丙烯酰氧乙基苄基二甲基氯化铵与核酸相互作用的共振光散射光谱及分析应用

用核酸与聚阳离子聚甲基丙烯酰氧乙基苄基二甲基氯化铵(PMBDAC)的相互作用导致共振光散射(RLS)增强的现象来测定核酸。考察了pH值、PMBDAC浓度和离子强度对体系共振光散射强度的影响。在优化条件下,建立了用RLS光谱测定微量核酸的新方法。方法的抗干扰能力较强,可允许大部分的常见金属离子、核苷酸、氨基酸、糖、蛋白质等干扰物质的存在。     

十二烷基二甲基苯氧乙基溴化铵的制备

苯酚与二溴乙烷在相转移催化剂存在正反反应制得β－溴化乙基苯工醚,盲人经合物与十二烷基二甲基叔胺反应制香下二烷基二甲基苯氧乙基省化铵。通过性质试验及红外光谱分析初步证产品的结构。     

聚甲基丙烯酰氧乙基三甲基氯化铵的合成研究

以甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,过硫酸铵/亚硫酸氢钠为引发剂,合成了聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)。单因素法考察了引发剂用量、反应温度以及反应时间对PDMC相对分子质量的影响。实验发现随引发剂用量的减少,PDMC相对分子质量趋于增大;反应温度从65℃升至85℃过程中,PDMC相对分子质量先增大后减小,75℃时,相对分子质量最大;随反应时间的延长,单体残留率逐渐降低,相对分子质量逐渐增大,但超过2 h后相对分子质量增大趋缓。     

聚甲基丙烯酰氧乙基三甲基氯化铵的合成研究

以甲基丙烯酰氧乙基三甲基氯化铵(DMC)为单体,过硫酸铵/亚硫酸氢钠为引发剂,合成了聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)。单因素法考察了引发剂用量、反应温度以及反应时间对PDMC相对分子质量的影响。实验发现随引发剂用量的减少,PDMC相对分子质量趋于增大;反应温度从65℃升至85℃过程中,PDMC相对分子质量先增大后减小,75℃时,相对分子质量最大;随反应时间的延长,单体残留率逐渐降低,相对分子质量逐渐增大,但超过2h后相对分子质量增大趋缓。     

甲基丙烯酰氧乙基三甲基氯化铵与丙烯酰胺的合成研究

丙烯酰胺(AM)与甲基丙烯酰氧乙基三甲基氯化铵(DMC)进行水溶液聚合,考察了引发剂浓度、温度、单体配比、pH值、引发剂等因素对共聚物的阳离子度、特性黏度以及相对分子质量的影响。结果表明,制备高相对分子质量的阳离子型聚丙烯酰胺的最佳工艺条件为:pH为8,温度为50℃,引发剂的用量为0.8 mmol/L,DMC∶AM(摩尔比)=1∶3。     

聚甲基丙烯酰氧乙基三甲基氯化铵的合成

以工业品甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,过硫酸铵(APS)为引发剂,乙二胺四乙酸四钠(Na4EDTA)为络合剂,采用一次性加入引发剂、两步升温引发的水溶液聚合方法合成聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)。用正交实验优化反应条件,得到的最佳工艺条件为：w(DMC)=72.5%,m(APS):m(DMC)和m(Na4EDTA):m(DMC)分别为0.20:100和0.018:100。在聚合反应引发温度T1为35℃下反应3h后,再在聚合反应熟化温度T2为50℃下完成反应3h。在最佳工艺条件下,得到的PDMC胶体产物的特征黏度为10.38 dL•g-1,单体转化率为98.40%。用FTIR和1HNMR对产物的结构进行了表征。该文所得结果为合成工艺的进一步优化和系列化PDMC产物的合成研究奠定了基础。     

聚甲基丙烯酰氧乙基三甲基氯化铵的合成

以工业品甲基丙烯酰氧乙基三甲基氯化铵(DMC)为原料,过硫酸铵(APS)为引发剂,乙二胺四乙酸四钠(Na4EDTA)为络合剂,采用一次性加入引发剂、两步升温引发的水溶液聚合方法合成聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)。用正交实验优化反应条件,得到的最佳工艺条件为:w(DMC)=72.5%,m(APS)∶m(DMC)和m(Na4EDTA)∶m(DMC)分别为0.20∶100和0.018∶100。在聚合反应引发温度T1为35℃下反应3 h后,再在聚合反应熟化温度T2为50℃下完成反应3 h。在最佳工艺条件下,得到的PDMC胶体产物的特征黏度为10.38d L/g,单体转化率为98.40%。用FTIR和1HNMR对产物的结构进行了表征。该文所得结果为合成工艺的进一步优化和系列化相对分子质量PDMC产物的合成研究奠定了基础。     

甲基丙烯酰氧乙基三甲基氯化铵聚合物合成和应用研究进展

甲基丙烯酰氧乙基三甲基氯化铵聚合物是一类带有季铵盐基团的高分子聚电解质,具有带正电荷、水溶性好、特征黏度易于控制、高效无毒等特点,广泛应用于石油开采、造纸、纺织、废水和污泥处理等行业中。首先,概述了聚甲基丙烯酰氧乙基三甲基氯化铵(PDMC)在提高产物特征黏度方面的合成研究进展,指出了PDMC在分子结构上的最新研究方向;然后,介绍了共聚物聚甲基丙烯酰氧乙基三甲基氯化铵-丙烯酰胺〔P(DMC-AM)〕的合成进展,重点探讨了溶液聚合法、乳液聚合法和其他聚合法对聚合物序列结构和特征黏度影响的研究进展;接着,对比不同性质的污泥处理实例,阐述了污泥性质对共聚物P(DMC-AM)絮凝性能的影响规律;最后,归纳了P(DMC-AM)在合成和应用中的问题并对未来的发展趋势进行了展望。     

淀粉-丙烯酰胺-甲基丙烯酰氧乙基三甲基氯化铵接枝共聚研究

采用氧化还原引发体系,在水溶液中接枝聚合制备了淀粉、丙烯酰胺(AM)与甲基丙烯酰氧乙基三甲基氯化铵(DMC)接枝共聚物。考察了反应温度、反应时间、引发剂浓度、单体质量比对接枝率、接枝效率及阳离子度的影响,确定了最佳反应条件:淀粉7.5g,AM15g,引发剂浓度0.4mmol/L,反应温度45℃,反应时间5h,m(DMC):m(AM)为1:3,所得接枝共聚物的接枝率为136.18%,接枝效率为79.8%,阳离子度为19.2%。     

高效液相色谱法分析甲基丙烯酰氧乙基三甲基氯化铵中的阻聚剂

利用反相高效液相色谱法 (HPLC) ,采用ExtendC18柱、以甲醇 -水 ( 0 .0 5 %高氯酸 )为流动相 (体积比为 5 5 :45 ) ,二极管阵列检测器对甲基丙烯酰氧乙基三甲基氯化铵 (简称DMC)中的阻聚剂对羟基苯甲醚进行了检测。试验结果证明 ,对羟基苯甲醚在0 .0 2mg/mL～ 2mg/mL浓度范围内与峰面积呈良好的线性关系。方法回收率为 98.9%～ 10 1.6% ,相对标准偏差为 1.3 2 % ,最低检测限为 5× 10 - 4mg/mL。     

Multiple order light scattering by ringed spherulites

The transmittivity [Point JJ. Bull Clas Sci Acad Roy Belg 1953;39:455; 1955;41:982. [1]] of light intensity through spherulitic films of poly(ethylene adipate) (PEA) is not uniform. These films may actually be used as multiple diffraction gratings. The intensity of the first order scattering depends reversibly on the temperature T of the film (between 10 and 59 °C). For sufficient film thickness (e.g. 30 μm), this intensity is an increasing function of T. It is, however, a decreasing function of T when the films are sufficiently thin (e.g. 2 μm). These, and other effects are explained by geometrical optics and by the electromagnetic theory of light. Evidently, these effects are not specific to PEA but are characteristic properties of ringed spherulites of polymers and other materials.     

Poly[(2-Hydroxy-4-Methoxy Benzophenone) Butylene] Resin and its Polychelates with Lanthanides(III): Synthesis and Characterization

ABSTRACT

The resin (polymeric ligand) was prepared from 2-hydroxy-4-methoxy benzophenone with 1,4-butane diol in the presence of polyphosphoric acid as a catalyst at 160°C for 9 h. The poly[(2-hydroxy-4-methoxy benzophenone) butylene] L = H(HMBP-BD) form 1:2, ML₂, complexes with M = La(III), Pr(III), Nd(III), Sm(III), Gd(III), Tb(III), and Dy(III). The polymeric ligand and its polychelates were characterized by elemental analyses, electronic spectra, and magnetic susceptibilities, IR-spectroscopy, NMR, and thermogravimetric analyses. The number average molecular weight (M¯n) of the resin was determined by Vapour Pressure Osmometry (VPO). All the polychelates are paramagnetic in nature. The resins and their polychelates were screened for their antimicrobial activity against E. coli, B. substilis, S. aureus (bacteria), and S. cerevisiae (yeast). It was found that the polychelates show good antimicrobial activity compared to the free polymeric ligand.     

N(2)-乙酰基-7-[(2-乙酰氧乙氧基)甲基]鸟嘌呤的转糖基作用

研究了N(2 ) 乙酰基 7 [(2 乙酰氧乙氧基 )甲基 ]鸟嘌呤通过转糖基作用生成其9位异构体N(2 ) 乙酰基 9 [(2 乙酰氧乙氧基 )甲基 ]鸟嘌呤的条件 ,转化率为 5 5 %。     

Novel High‐Performance Talc/Poly[(butylene adipate)‐co‐terephthalate] Hybrid Materials

New talc/PBAT hybrid materials were prepared through reactive extrusion. First, PBAT was free‐radically grafted with MA to improve the interfacial adhesion between PBAT and talc. Then, the resulting MA‐g‐PBAT was reactively melt‐blended with talc through esterification reactions of MA moieties with the silanol functions from talc. Sn(Oct)₂ and DMAP were used as catalysts. Interestingly, the tensile properties for these compatibilized composites were improved due to a better interfacial adhesion between both partners. XPS showed the formation of covalent ester bonds between the silanol functions from talc particles, and the MA moieties grafted onto the polyester backbones.

     

Electrochemical performances of electric double layer capacitor with UV-cured gel polymer electrolyte based on poly[(ethylene glycol)diacrylate]-poly(vinylidene fluoride) blend

Poly[(ethylene glycol)diacrylate]-poly(vinylidene fluoride), a gel polymer blend with ethylene carbonate:dimethyl carbonate:ethylmethyl carbonate (EC:DMC:EMC, 1:1:1 volume ratio) and containing 1.0 M of lithium hexafluoro phosphate (LiPF₆) as liquid components, is employed as a gel polymer electrolyte for an electric double layer capacitor (EDLC). Its electrochemical characteristics is compared with that of liquid organic electrolyte mixture of ethylene carbonate, dimethyl carbonate and ethylmethyl carbonate in a 1:1:1 volume ratio containing 1.0 M LiPF₆ salt. The specific surface area of the activated carbon powder as an active material is 1908 m²/g. Liquid poly[(ethylene glycol)diacrylate] (PEGDA) oligomer with a high retention capability of liquid electrolytes is cured by UV irradiation and poly(vinylidene fluoride)-hexafluoropropylene (PVdF-HFP) copolymer with a porous structure endows polymer matrix with high mechanical strength.The specific capacitance of EDLC using the gel polymer electrolyte (GPE-EDLC) shows 120 F/g, which is better than the liquid organic electrolyte. Good cycling efficiency is observed for a GPE-EDLC with high retention capability of liquid components. The high specific capacitance and good cycling efficiency are most likely due to the polarization resistance of EDLC with the gel polymer electrolyte, which is lower than the liquid organic electrolyte. This may result from the distinguished adhesion between the activated carbon electrode and the gel polymer electrolyte, as well as high retention capability of liquid components.Power densities of GPE-EDLC and LOE-EDLC shows 1.88 kW/kg and 1.21 kW/kg, respectively. However, the energy densities are low in both electrolytes.The GPE-EDLC exhibits rectangular cyclic voltammogram similar to an ideal EDLC within operating voltage range of 0 V-2.5 V. It should be noted that a region of electric double layer means a wide voltage and a rapid formation. Redox currents of both EDLCs are not observed in the sweep region and the cyclic voltammograms are unchanged on repeated runs. The observed leakage current shows 49 μA after 720 s at a constant voltage of 2.5 V, due to the high ionic conductivity of 1.5 × 10⁻³ S cm⁻¹ during storage time. Swelling and well-developed pore structures of the GPE blend films allow ions and solvents to move easily.     

Preparation of monodispersed ZrO2 nanoparticles and their applications in poly[(vinylidene fluoride)‐co‐hexafluoropropylene]‐based composite polymer electrolytes

To improve the electrochemical performance of pure poly[(vinylidene fluoride)‐co‐hexafluoropropylene] (P(VDF‐HFP))‐based gel polymer electrolytes, different amounts of monodispersed ZrO₂ nanoparticles were introduced to fabricate P(VDF‐HFP)/ZrO₂ composite polymer electrolytes (CPEs) using the phase inversion method and activated processes, in which the monodispersed ZrO₂ nanoparticles were synthesized by an easy route without any chelating agents or surfactants, and confirmed using scanning electron microscopy, particle size distribution measurement and X‐ray diffraction. The characterization results show that the as‐fabricated CPE membranes present not only an abundant porous structure, but also an improved mechanical strength. In particular, sample CPE‐5 presents the best properties when the doped content of the monodispersed ZrO₂ nanoparticles reaches 5 wt% in the polymer matrix, in which the liquid uptake and ionic conductivity at room temperature are about 192.4% and 3.926 mS cm^?1, and the electrochemical working window and thermal decomposition temperature can increase to 5.1 V and 420 °C, respectively. Moreover, an assembled LiCoO₂/CPE‐5/Li coin cell can deliver excellent rate and cycling performance, in which the discharge specific capacity of the cell can show about 83.95% capacity retention at 2.0 C after 85 cycles. © 2018 Society of Chemical Industry     

A facile method for the detection of DNA by using gold nanoparticle probes coupled with dynamic light scattering

In this paper, we present a simple and rapid method for deoxyribonucleic acid (DNA) detection using gold nanoparticle probes coupled with dynamic light scattering (DLS) analysis. The redox agent 1,4-dithio-dl-threitol cross-links the gold nanoparticles (AuNPs) to form clusters, while the monothiol DNA could terminate the formation and stabilize the assembled clusters by their negatively charge-based repulsions. By varying the concentration of DNA, the different sizes of DNA-AuNP clusters can be obtained. The sizes of the DNA-AuNP clusters were determined by DLS. A linear correlation was obtained between the sizes and the logarithm of DNA concentration from 2 nM to 5 μM with a detection limit of 1 nM (S/N = 3).     

2-[(异亚丙基氨基)氧基]乙基-(S)-乳酸酯的合成

[目的]2-[(异亚丙基氨基)氧基]乙基-(S)-乳酸酯是合成除草剂喔草酯的关键中间体,传统的合成方法中选用硫酸为催化剂,对设备腐蚀性强,三废处理困难,研究绿色环保的合成方法是必要的.[方法]首先以丙酮肟和环氧乙烷为原料,水为溶剂,氢氧化钙为催化剂,在30℃下反应15h,制备2-[(异亚丙基氨基)氧基]乙醇,收率为49.7％;然后2-[(异亚丙基氨基)氧基]乙醇再与L-乳酸经过酯化反应,以原料乳酸为催化剂,生成目标物2-[(异亚丙基氨基)氧基]乙基-(S)-乳酸酯,收率为82.0％.[结果]分别实验了溶剂、原料配比、催化剂、反应时间和反应温度等因素对收率的影响,目标物总收率为40.8％,其结构经过1H NMR鉴定确认.[结论]该路线操作简单,经济环保,收率高于其他文献,适合工业化生产.     

2-[(1-羟基-2-萘基)羰基]苯甲酸的合成与表征

以苯酐和-α萘酚为原料,在B2O3催化下合成了2-[(1-羟基-2-萘基)羰基]苯甲酸,反应的优化条件为:n(B2O3)∶n(苯酐)∶n(-α萘酚)=1.5∶1.5∶1,反应温度为180￣190℃,反应时间为2.0h,收率达97.8%,并通过元素分析、1H NMR、IR、EIMS对产物结构进行了表征。     

Comb-like poly(4-vilylpyridinium) salts with dodecylsulfate, sodium bis(2-ethylhexyl) sulfosuccinate and bromide counter ions. Small-angle X-ray scattering and dynamic light scattering study

Poly(4-vinylpyridine) derivatives alkylated with dimethylsulfate, octylbromide and dodecylbromide were synthesized. Bromide anions in the polymer salts were substituted with octylsulfate, dodecylsulfate or bis(2-ethylhexyl)sulfosuccinate (AOT) anions using ion-exchange reactions. The small-angle X-ray scattering (SAXS) studies of the structure of the comb-like polysalts demonstrated their highly-ordered structure. Loading the comb-like polycation with the surfactant anions leads to additional ordering of the polysalts structure. In the case of large AOT anions the transition from lamella to hexagonal structure is observed. Polyelectrolyte - surfactant complexes (PEC) of poly(4-vinyl-1-methylpyridinium) cation with octylsulfate and dodecylsulfate counter ions demonstrate a higher degree of order than the comb-like polymers having a similar chemical structure. The SAXS studies were complemented by dynamic light scattering study of the solutions of the polymers in chloroform. In the solution the comb-like polymers and their complexes with linear surfactants have coil conformations with the size of the coils close to that of the original poly-4-vinylpyridine. The conformations of PECs with octylsulfate and dodecylsulfate counter ions are more unfolded than those of the corresponding comb-like polymers.