Poly(4‐vinyl pyridine)‐grafted graphene oxide for drug delivery and antimicrobial applications

Graphene oxide (GO) was covalently functionalized with poly(4‐vinyl pyridine) (P4VP) by atom transfer radical polymerization for drug delivery and antimicrobial applications. The physiochemical properties, chemical structure, composition and morphology of the P4VP‐functionalized GO (GO‐P4VP) were studied. Simple physisorption of a cancer drug, camptothecin (CPT), via π ? π stacking and/or hydrophobic interactions on the GO‐P4VP was tested for drug loading and its release by altering the pH. The GO‐P4VP has low cytotoxicity, and the CPT‐loaded GO‐P4VP exhibited a high potency for killing cancer cells in vitro. Prominent antimicrobial properties against Escherichia coli and Staphylococcus aureus were also observed. Thus, the GO‐P4VP can be utilized as a drug delivery vector with high biocompatibility, solubility and stability in physiological solutions, a suitable payload capacity and excellent bacterial toxicity. Owing to its small size, low cost, large specific area, ready scalability and useful non‐covalent interactions, GO‐P4VP is a novel material for biomedical, industrial and environmental applications. © 2015 Society of Chemical Industry     

TANPyO及其金属配合物的合成与性能

用2,4,6-三氨基-3,5-二硝基吡啶-1-氧化物（TANPyO）作配体,合成了两种过渡金属[Ni（Ⅱ）和Cu（Ⅱ）]配合物,并用红外、元素分析、DSC、TG-DTG 进行了表征。研究了两种配合物对高氯酸铵（AP）热分解的影响。按 GJB772A -1997测试了TANPyO的感度。结果表明,配合物的热分解过程仅由1个剧烈放热峰组成,剩余残渣为金属氧化物。两种配合物使AP高温分解峰温度分别提前47．14℃和98．24℃,分解速度加快,放热量增加,显示这两种配合物对AP热分解有良好的催化效果。撞击落高为300 cm,摩擦感度和静电火花感度均为0,表明TANPyO是一种非常钝感的含能材料。     

7-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物合成及性能

设计了一种新化合物(7-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物)的合成方法。以2-氯-4-氨基吡啶为起始原料,经硝化、叠氮化、热解环化得到目标化合物,总收率为42%,并采用核磁共振、红外、质谱、元素分析对其进行结构表征。利用差示扫描量热法研究了目标化合物的热性能,其分解温度为215.93℃,按GJB772A-1997方法实测摩擦感度和撞击感度都为0,表明7-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物是一种钝感含能化合物。     

高效疏水电荷诱导色谱介质的基团修饰及其色谱行为的初步研究

以粒径10μm、孔径300球形硅胶为载体,以γ-缩水甘油醚氧丙基三甲氧基硅烷(KH-560)为中间偶联剂,将4-巯基吡啶键合至硅胶上,制备了高效疏水电荷诱导色谱介质。通过单因素实验,探讨了反应温度、反应时间、KH-560的浓度对活化密度的影响,结果表明,在反应温度为75℃,反应时间为10 h条件下,KH-560的利用率大,可获得较宽范围的活化密度,此外还考察了缓冲液pH、反应温度、反应时间、4-巯基吡啶浓度对偶联密度的影响。结果表明,在pH=7.5的缓冲液,反应温度40℃,反应时间6 h下,4-巯基吡啶利用率高,通过控制4-巯基吡啶的浓度,可获得较宽范围的配基密度。最后,于高效液相色谱条件下,通过等度洗脱,考察了流动相pH对牛血清蛋白和溶菌酶保留因子的影响。并通过梯度洗脱,分离了不同等电点的牛血清蛋白和溶菌酶,验证了该介质的高效疏水电荷诱导色谱行为。     

顶空-气相色谱法测定水中的丙烯腈和吡啶

采用顶空-气相色谱法对水中丙烯腈和吡啶进行分析测定,并对实验的色谱条件、顶空条件进行了优化,实验结果表明该方法在丙烯腈0.01~1.0mg·L-1以及吡啶0.05~5.00mg·L-1范围内,线性相关系数在0.9995以上,相对标准偏差为1.9%。对4种水样中,加标质量浓度分别为0.05mg·L-1的丙烯腈和0.2mg·L-1的吡啶,以及质量浓度分别为0.2mg·L-1的丙烯腈和1.0mg·L-1的吡啶测定7次,其回收率为89.6%~100%。测试结果表明该方法操作简单,灵敏度较高,适用于水中丙烯腈和吡啶的测定。     

Synthesis of organic molecule donor for efficient organic solar cells with low acceptor content

A new planar A-D-A structured organic small molecule semiconductor (O-SMS) with dialkyl-thiophene substituted benzodithiophene (BDT) as central electron-rich core flanked by relatively electron-deficient units of [1,2,5]thiadiazolo[3,4-c]pyridine (PTz) and terminated with alkyl-bithiophene as π-conjugated end-caps, BDTDPTz, was designed and synthesized for the application as donor material in organic solar cells (OSCs). BDTDPTz possesses wider absorption spectra with an optical bandgap of 1.65 eV, lower the highest occupied molecular orbital (HOMO) energy level of −5.42 eV and highly crystalline structures in solid films. The OSCs based on BDTDPTz:PC₇₁BM blend film with a lower PC₇₁BM content of 40% demonstrate a power conversion efficiency (PCE) of 6.28% with a relatively higher open-circuit voltage of 0.868 V and short circuit current density of 12.83 mA cm⁻². These results indicate that highly coplanar and crystalline structure of BDTDPTz can effectively reduce the content of fullerene acceptor in the active layer and then enhance the absorption and PCE of the OSCs.     

Chromatographic Separation of Trivalent Actinides by Using Tertiary Pyridine Resin with Methanolic Nitric Acid Solutions

Chromatographic separation of trivalent actinides (Am, Cm and Cf) was performed by using a tertiary pyridine resin embedded in silica beads with methanolic nitric acid solutions. The trivalent actinides were eluted from the resin column in the reverse order of atomic numbers (Cf-Cm-Am). Higher concentration of methanol in the mixed solution accelerated both the adsorption of these elements on the resin and the separability for these elements. Americium was clearly separated from Cm and Cf by using a 1 cm-ø × 10 cm-height column with a 60vol% of methanol/40 vol% of concentrated nitric acid mixed solution at ambient temperature.     

Catalytic performance of methacrylate‐based poly‐4‐(dialkylamino)‐pyridines: activity prediction via NMR shifts

The synthesis of the 4‐(dialkylamino)pyridine derivative 3‐(4‐(pyridin‐4‐yl)piperazin‐1‐yl)propyl methacrylate and its copolymerization with n‐butyl methacrylate are presented. The catalytic activity was evaluated in the acylation of tert‐butanol with acetic anhydride yielding tert‐butyl acetate. It is observed that the activity of polymer‐attached 4‐(dimethylamino)pyridine analogues correlates remarkably well with the chemical shift of the β‐pyridyl protons. Differences in catalytic efficiency result from distinct electronic densities of the pyridine ring, while embedding the catalytically active moiety into a polymeric structure has nearly no deleterious effect on the performance. © 2015 Society of Chemical Industry     

Highly efficient synthesis of benzopyranopyridines via ZrP2O7 nanoparticles catalyzed multicomponent reactions of salicylaldehydes with malononitrile and thiols

ZrP₂O₇ nanoparticles as an efficient catalyst have been used for the preparation of benzopyrano[2,3-b]pyridines from the four-component condensation reaction of salicylalde-hydes, thiols, and 2 equiv. of malononitrile under reflux conditions in ethanol in excellent yields and short reaction times.     

Highly refractive polyimides containing pyridine and sulfur units: synthesis and thermal,mechanical, solubility and optical properties

Two series of isomers containing pyridine and sulfur unit aromatic diamine monomers, 4,4′‐bis(5‐amino‐2‐pyridinylsulfanyl)diphenyl sulfide ( 2a ), 4,4′‐bis(6‐amino‐3‐pyridinylsulfanyl)diphenyl sulfide ( 2b ) and 4,4′‐bis(5‐amino‐6‐methyl‐2‐pyridinylsulfanyl)diphenyl sulfide ( 2c ), 4,4′‐bis(5‐amino‐4‐methyl‐2‐pyridinylsulfanyl)diphenyl sulfide ( 2d ), were designed and synthesized. Aimed at clarifying the structure–property relationships of pyridine‐ and sulfur‐containing high refractive polymers, 2a was polymerized with various dianhydrides to prepare polyimides PI ‐1?PI ‐7 and 2b , 2c , 2d were reacted with 4,4′‐[p ‐thiobis(phenylenesulfanyl)]diphthalic anhydride to prepare polyimides PI ‐8?PI ‐10. The polyimides showed excellent optical properties with average refractive indices ranging from 1.7006 to 1.7620 and birefringence as low as 0.0056. Meanwhile, comparative studies on their properties including solubility, thermal and mechanical, and optical transparency properties were performed. Some property differences of the isomers caused by the sequence changes were found. © 2017 Society of Chemical Industry