光敏共聚物P(St/VM-co-MA)自组装胶体粒子及其性能

以苯乙烯类光敏单体7-(4-乙烯基苄氧基)-4-甲基香豆素(VM)、苯乙烯(St)、马来酸酐(MA)为共聚单体,采用自由基聚合法制备了光敏性双亲共聚物P(St/VM-co-MA).在选择性溶剂(N,N-二甲基甲酰胺(DMF)/H2O)中对P(St/VM-co-MA)进行自组装,用透射电镜(TEM)和动态激光光散射(DLS)表征了自组装胶体粒子的形态、粒径大小及其分布.利用紫外光照使胶体粒子中香豆素基元发生光二聚反应,形成交联胶体粒子,并用紫外-可见光分光光度计(UV-Vis)跟踪其交联过程.用DLS研究了交联和未经交联胶体粒子的粒径和结构稳定性,用激光扫描共聚焦显微镜(LSCM)和光学显微镜考察了胶体粒子的乳化、包覆性能.结果表明:交联和未经交联胶体粒子均具有乳化性,且在乳化过程中可实现对油溶性染料的包覆.胶体粒子交联后,粒径有所减小,结构稳定性、乳化性能、包覆性能均有所提高.     

光敏性无规共聚物P(FA_2C-co-AA)的自组装及乳化性能

光敏性单体ε-己内酯改性丙烯酸酯肉桂酸酯(FA2C)与丙烯酸(AA)在偶氮二异丁腈(AIBN)的引发作用下,于N,N-二甲基甲酰胺(DMF)中发生自由基共聚反应,制备了具有光敏性的双亲无规共聚物P(FA2C-co-AA)。以红外光谱、凝胶渗透色谱、差示扫描量热和紫外光谱等分析测试手段对共聚产物进行了表征。P(FA2C-co-AA)在选择性溶剂DMF水溶液中自组装得到纳米粒径的胶体粒子。用紫外光引发胶体粒子内双键发生光交联反应,得到稳定的胶体粒子,并用动态激光光散射(DLS)表征了胶体粒子交联前后的粒径变化。结果表明:该胶体粒子具有良好的乳化性能。     

探索光敏性共聚物P(St/CS-alt-MA)的自组装及其乳化行为

以苯乙烯(St)、马来酸酐(MA)、香豆素苯乙烯醚化物(CS)为单体, 通过自由基溶液聚合合成了双亲性交替共聚物P(St/CS-alt-MA), 用凝胶渗透色谱、核磁共振等对聚合物结构进行表征, 并对其溶液自组装及组装体的乳化性进行了研究. 结果表明双亲性P(St/CS-alt-MA)可以在选择性溶剂中进行自组装形成马来酸酐单元为亲水微区、CS与苯乙烯单元为疏水微区的胶体粒子, 用紫外分光光度计, XPS, TEM研究了聚合物胶体粒子性质, 结果显示, P(St/CS-alt-MA)在水溶液中可以形成两亲性聚合物胶体粒子, 亲水单元在胶粒表面富集, 该两亲性聚合物胶体粒子具有良好的乳化性能.     

香豆素改性透明质酸颗粒乳化剂的制备及应用

利用7-(2-羟基乙氧基)-4-甲基香豆素(HEMC)疏水改性透明质酸(HA)制得光敏双亲大分子(HA-HEMC),并通过自组装形成了HA-HEMC胶体粒子。通过核磁共振氢谱和紫外分光光度计确定了HA-HEMC的结构及取代度;采用动态激光光散射、纳米粒度仪和透射电镜等手段对胶体粒子的性质及形貌进行了表征。进一步以HA-HEMC胶体粒子作为颗粒乳化剂稳定油水界面,研究了胶体粒子质量浓度、油相类型、水相pH和盐浓度对胶体粒子乳化性能的影响。结果表明:HA-HEMC可以在选择性溶剂中自组装形成粒径约为236nm的球形胶体粒子;该胶体粒子能够在较宽的pH范围内(3~11)稳定水包油型乳液且所得乳液有良好的耐盐性;此外,HAHEMC胶体粒子还能稳定多种油-水体系。     

共溶剂性质对双亲性无规共聚物P(St-co-DM)胶束化行为及其性能的影响

以苯乙烯(St)和甲基丙烯酸二甲氨乙酯(DMAEMA)为共聚单体, 通过普通自由基溶液聚合合成了双亲性无规共聚物P(St-co-DM). 用傅里叶变换红外(FTIR)光谱、核磁共振氢谱(¹H NMR)、凝胶渗透色谱(GPC)和差示扫描量热(DSC)仪对聚合物结构进行表征. 研究了共溶剂的性质对P(St-co-DM)自组装胶束结构及其乳化性能的影响. 用透射电镜(TEM)和动态激光光散射(DLS)表征了自组装胶体粒子的形态、粒径大小及其分布. 通过测量胶束在甲苯/水界面的接触角表征胶束表面性能. 结果表明: P(St-co-DM)以四氢呋喃(THF)为共溶剂自组装时, 胶束的临界聚集水含量较大, 胶束表面亲水性较强, 流体力学半径较大; 用二氧六环或THF为共溶剂, 水为选择性溶剂, P(St-co-DM)自组装可以得到外层松散、内层比较密实的球状胶束, 用N,N-二甲基甲酰胺(DMF)为共溶剂时, 胶束整体呈现比较密实的球状胶束; 分别用DMF、二氧六环和THF为共溶剂制备的胶束, 其接触角均值都小于90°, 可形成O/W型(水包油型)乳液. 乳化实验结果表明, 以二氧六环和THF为共溶剂制备的胶束作为颗粒乳化剂制备的乳液性能较好.     

多重敏感性双亲共聚物P(DM-co-AA-co-CA)的自组装及性能

以甲基丙烯酸二甲胺乙酯（DM）、丙烯酸（AA）和香豆素丙烯酸酯化物（CA）为共聚单体,通过普通自由基溶液聚合合成了多重敏感性双亲共聚物P(DM-co-AA-co-CA),用傅里叶变换红外（FTIR）、核磁共振（1H-NMR）、凝胶渗透色谱（GPC）和差示扫描量热仪（DSC）对聚合物结构进行表征．在选择性溶剂四氢呋喃/水中对所得多重敏感性双亲共聚物P(DM-co-AA-co-CA)进行自组装,结果表明,调节组装环境的pH值可以得到荷正电或负电的两性胶束粒子．用紫外可见光分光光度计、荧光分光光度计、Zeta电位测定仪、DLS和TEM研究了多重敏感性双亲共聚物的溶液自组装及其组装体的性能,结果显示,调节pH值可以有效的控制胶束的粒径大小及其LCST,并在pH为8.54时胶束溶液的紫外吸收和荧光发射强度达到最大值,且该胶束溶液在酸碱性较强时具有良好的乳化性能．     

双亲性无规光敏共聚物的疏水基元对其自组装胶束乳化性能的影响

设计合成了一系列具有不同化学组成的双亲性无规光敏共聚物,聚(7-对乙烯基苄氧基-4-甲基香豆素-r-丙烯酸)(P(VM-r-AA)),通过选择性溶剂法自组装获得纳米胶束,并将纳米胶束用作大分子颗粒乳化剂,研究其在甲苯-水界面的稳定性能。研究表明:聚合物疏水基元含量的增加使自组装胶束结构由溶胀的微凝胶状向刚性颗粒状转变;同时,胶束初始乳化效率增加,但油水界面吸附稳定性显著下降。此外,通过对疏水基元PVM的摩尔分数为12%的胶束进行辐照交联,并研究其在不同pH下的乳化性能,结果表明:胶束表面溶胀的双亲性链段对其乳化性能产生了重要的影响。未交联的胶束保持着良好的乳化性能;而交联的胶束形变能力变差、刚性增强,在碱性条件下,彻底失去乳化能力。     

交替共聚物P(St-alt-Ma-Dopa)的自组装及乳化性能

以二甲亚砜(DMSO)为溶剂, 用多巴胺(Dopamine)胺解聚(苯乙烯-alt-马来酸酐)(P(St-alt-Man))制备双亲交替共聚物P(St-alt-Ma-Dopa). 在选择性溶剂(N,N-二甲基甲酰胺(DMF)/水)中对P(St-alt-Ma-Dopa)进行溶液自组装, 用紫外分光光度计(UV)、透射电镜(TEM)、荧光探针技术、zeta电位仪等技术研究了添加剂(HCl, NaOH或NaCl)对P(St-alt-Ma-Dopa)自组装行为的影响及其胶体粒子的乳化性能. 结果表明, P(St-alt-Ma-Dopa)链在选择性溶剂(DMF/水)中可自组装形成球状胶体颗粒, 其临界聚集水含量(CWC)明显大于P(St-alt-Man). 体系的pH值、盐浓度等对P(St-alt-Ma-Dopa)胶体粒子的性质(粒子大小、zeta电位、亲疏水性等)有较大的影响, 引入多巴胺结构使交替共聚物胶体粒子的乳化性能有所提高.     

肉桂酸改性透明质酸颗粒乳化剂的制备及性能

将具有紫外吸收性能的单体肉桂酸(CA)引入天然大分子透明质酸(HA)中,制得疏水性改性HA(HA-CA),然后在二甲亚砜与水的混合溶剂中自组装制备HA-CA胶体粒子,并以之为颗粒乳化剂稳定油水界面制备Pickering乳液。通过紫外、核磁、纳米粒度仪、透射电镜、光学显微镜等方法对HA-CA、HA-CA胶体粒子及其所稳定的乳液进行表征。结果表明,HA-CA可以在选择性溶剂中自组装形成粒径约为95nm的球形胶体粒子;所得的HA-CA胶体粒子可以有效地稳定油/水界面,制备水包油(O/W)型的Pickering乳液,且所得乳液具有良好的耐盐性和细胞相容性;此外该胶体粒子可稳定多种油/水体系,具有一定普适性。     

光交联Pickering乳液中的粒子稳定剂制备胶体体微胶囊

研究了光敏性聚合物刷修饰二氧化硅纳米粒子的制备及其乳化行为, 提供了一种制备新颖“胶体体”微胶囊的方法. 首先, 在二氧化硅纳米粒子表面引入原子转移自由基聚合(ATRP)引发剂分子, 通过表面引发ATRP得到含有香豆素侧基聚合物刷光敏性的纳米二氧化硅粒子(SiO₂-PMMA-PCMA); 然后, 以该粒子为乳化剂制备油包水型的皮克林乳液; 最后, 在紫外光的照射下引发香豆素侧基的交联反应从而得到“胶体体”微胶囊. 结果表明, 香豆素单体7-(2-甲基丙烯酰乙氧基)-4-甲基香豆素(CMA)和SiO₂-PMMA-PCMA在紫外光作用下都可以发生交联反应, 以SiO₂-PMMA- PCMA纳米粒子作乳化剂可以制备稳定的皮克林乳液, 光交联后得到的“胶体体”微胶囊的平均粒径约为170 μm.     

中空纤维液相微萃取-超高效液相色谱-串联质谱法测定儿童玩具中6种致敏香豆素类化合物

建立了超高效液相色谱-串联质谱测定儿童玩具中6种致敏香豆素类化合物(香豆素、7-甲基香豆素、7-甲氧基香豆素、7-乙氧基-4-甲基香豆素、4,6-二甲基-8-叔丁基香豆素和六氢香豆素)的分析方法。样品前处理采用中空纤维液相微萃取技术,优化后的萃取实验条件为:萃取剂正辛醇,搅拌速度700 r/min,萃取时间50 min,氯化钠加入量0.7 g。萃取液经ACQUITY UPLC BEH Phenyl色谱柱(150 mm×2.1 mm,1.7μm)分离,目标化合物在电喷雾离子源正离子模式下电离,采用多反应监测模式进行定性定量分析。结果表明,6种致敏香豆素类化合物的定量限为2μg/kg(7-乙氧基-4-甲基香豆素、4,6-二甲基-8-叔丁基香豆素)或10μg/kg(香豆素、六氢香豆素、7-甲基香豆素、7-甲氧基香豆素),在10~120μg/kg范围内不同加标水平下的平均回收率为70.8%~118.9%,相对标准偏差为0.19%~16.34%(n=6)。该法准确、灵敏、可靠,适用于玩具产品的实际检验工作和产品质量控制。     

Development of electrochemical and optoelectronic performance of new 7-{[1H-indol-3-ylmethylidene]amino}-4-methyl-2H-chromen-2-one dye

Journal of Solid State Electrochemistry - A new 7-{[1H-indol-3-ylmethylidene]amino}-4-methyl-2H-chromen-2-one dye (3) was synthesized by the reaction of 7-amino-4-methyl coumarin with...     

Magnetic nanoparticles modified with DTPA-AMC-rare earth for fluorescent and magnetic resonance dual mode imaging

In the present study, we report new water-soluble cell fluorescence imaging and contrast agents that are based on DTPA-AMC(7-amino-4-methyl coumarin)-Eu(3+) and DTPA-AMC(7-amino-4-methyl coumarin)-Gd(3+) compounds conjugated to Fe(3)O(4) NPs via a PEG-NH(2) linker. The novel Fe(3)O(4) NP-conjugates present two main advantages for cell fluorescence labelling: water solubility and targeting ability. The in vitro experiments demonstrate that water-soluble Fe(3)O(4) NPs-DBI-PEG-NH-DTPA-AMC(7-amino-4-methyl coumarin)-Eu(3+) has excellent cell permeating activity. Moreover, the relaxation rate test of Fe(3)O(4) NPs-DBI-PEG-NH-DTPA-AMC(7-amino-4-methyl coumarin)-Gd(3+) shows a higher T1 relaxation effect than traditional DTPA-Gd(3+) MRI agents. According to in vivo liver MRI experiments, better contrast of the liver was achieved after addition of Fe(3)O(4) NPs-DBI-PEG-NH-DTPA-AMC(7-amino-4-methyl coumarin)-Gd(3+). The results will provide a significant guide for researchers exploring the biomedical applications of superparamagnetic Fe(3)O(4) NPs.     

均匀Fe~3O~4胶体粒子形成机理II. 低温Mossbauer谱研究

在液氮温度下, 测定了均匀Fe~3O~4胶体粒子制备过程中陈化时间为1小时内的不同时间所得样品的Mossbauer谱。结果表明, γ-FeOOH为Fe~3O~4均匀胶粒形成过程的中间产物, 并提出均匀Fe~3O~4胶粒的形成机理。     

Conversion of 3-Carbethoxy-4-methyl Coumarin Derivatives into Several New Annelated Coumarin Derivatives

The reaction of ethyl esters of 4-methyl-2-oxo-2H-l-benzo(naphtho) pyran.3-carboxylic acids (1) with aromatic aldehy-des in the presence of piperidine yielded 4-styryl-3-carboxami-dopiperidyl connmrin derivatives 4. The reaction of hydrazlne hydrate with 1 gave acetophenone hydrozone derivatives 5 and acetophenone azine derivatives 6. The reaction of 1 with prima-ry amines afforded compomlds 7—9. And the treatment of la with Grignard reagents afforded 3-aroyl-4-methyl coumarin derivatives 10.     

Terpenoids and coumarins isolated from the fruits of Poncirus trifoliata

Four new triterpenes, 21alpha-methylmelianodiol (1), 21beta-methylmelianodiol (2), hispidol A 25-methyl ether (3) and hispidol B 25-methyl ether (4), and a new coumarin, isoschininallylol (5), were isolated from the fruits of Poncirus trifoliata RAFINESQUE, along with seventeen known compounds. The structures of the new compounds (1 - 5) were elucidated by interpretation of their spectroscopic data.     

Both core- and shell-cross-linked nanogels: photoinduced size change, intraparticle LCST, and interparticle UCST thermal behaviors

New thermal- and photoresponsive core-shell nanogel particles were obtained from self-assembly in aqueous solution of a double-hydrophilic block copolymer (DHBCP) of which the two blocks could be photo-cross-linked via the reversible photodimerization and photocleavage of coumarin moieties. The diblock copolymer, consisting of poly[N,N-dimethylacrylamide-co-4-methyl-[7-(methacryloyl)oxyethyloxy]coumarin] and poly[N-isopropylacrylamide-co-4-methyl-[7-(methacryloyl)oxyethyloxy]coumarin] (P(DMA-co-CMA)-b-P(NIPAM-co-CMA)), was synthesized by using reversible addition-fragmentation chain transfer (RAFT) polymerization. At T > LCST of the P(NIPAM-co-CMA) block, core-shell micelles were formed and UV light irradiation at λ > 310 nm resulted in cross-linking of both the micelle core of P(NIPAM-co-CMA) and the micelle shell of P(DMA-co-CMA); subsequent cooling of the solution to T < LCST gave rise to water-soluble, swollen nanogel particles. Upon UV light irradiation at λ < 260 nm, the decrease of cross-linking density could increase the swelling of nanogel particles by ～23% in diameter. By alternating irradiation with the different wavelengths, the average hydrodynamic diameter of nanogel particles was tunable between ～58 and ～47 nm. Interestingly, upon further cooling of the solution, aggregation occurred for nanogel particles with a moderate cross-linking density (10%-40% dimerization of coumarin moieties). Therefore, such core- and shell-cross-linked nanogel could display both "intraparticle" LCST (solubility of polymer chains forming the core) and "interparticle" UCST (solubility of particles). The possible mechanism and the effect of dimerization degree on the UCST behavior were discussed.     

Microwave-assisted solvent free synthesis of hydroxy derivatives of 4-methyl coumarin using nano-crystalline sulfated-zirconia catalyst

Nano-crystalline sulfated-zirconia solid acid catalyst has been studied for microwave-assisted solvent free synthesis of hydroxy derivatives of 4-methyl coumarin by Pechmann reaction. The catalyst showed good activity for activated m-hydroxy phenol substrates, viz., phloroglucinol and pyrrogallol with ethyl acetoacetate for the synthesis of 5,7-dihydroxy 4-methyl coumarin and 7,8-dihydroxy 4-methyl coumarin, respectively, showing significant yields ranging from 78 to 85% within 5–20 min at 130 °C. However, the less activated phenol and m-methyl phenol was observed to be inactive for the synthesis of 4-methyl coumarin and 4,7-dimethyl coumarin, respectively, under the studied experimental conditions.     

VISIBLE LIGHT PHOTOPOLYMERIZATION OF METHYL METHACRYLATE COINITIATED WITH TITANOCENE AND KETOCOUMARIN DYE*

The photosensitive system which can initiate methyl methacrylate with visible light was composedof compound 1 bis(η-5-cyclopentadienyl)-bis[2,6-difluoro-3-(1-H-pyrrolyl)phenyl]titanium (titanocene) andcompound 2 [(3,3'-carbonylbis(7-diethylamino coumarin)] (ketocoumarin dye). The high photosensitiveinitiating efficiency of this photosensitive system could be very promising for efficient system for laser (Ar~+488 nm) to plate and photocuring for thick coating and ink. The variation of UV-visible spectrum ofcompound 2 during irradiation indicates that photolysis of compound 2 is through its triplet state and it canbe quenched by O_2. The much quicker photobleaching of the photosensitive system suggests that there existscertain quick electron transfer reaction between compounds 1 and 2.