Structural and Textural Transitions of the Zn-BDC Materials During Dehydration-Rehydration Process

A Zn-BDC(1,4-benzene-dicarboxylic acid)compound has been studied herein during reversibly adsorbing and desorbing water from a dimethyl formamide(DMF)solvent.The compound is structurally stable and can be reused.XRD,TG,SEM,and BET results show that the morphology,textural properties and phase can gradually transform from a non-porous compound into a porous Zn-MOF by being exposed in the steam of DMF with trace water.This dried phase[Zn(BDC)]is able to reversibly remove/uptake coordinating water molecules,which can provide Zn-BDC compound with the ability to dehydrate the solvent.

Zn-BDC/Zn-BTC/纤维素三元复合水凝胶的保水性

以Zn-BDC/Zn-BTC二元混合MOFs为改性剂,对纤维素水凝胶进行掺杂改性,制备了Zn-BDC/Zn-BTC/纤维素三元复合水凝胶材料。利用FT-IR、XRD、SEM表征了其微观结构,并以质量分数、掺杂比例、pH、盐溶液、温度为环境响应因子,研究了三元复合水凝胶的保水效果。结果表明,当质量分数为15%,Zn-BDC/Zn-BTC掺杂比例为9:1时,三元复合水凝胶材料的最高溶胀率为920.63%,较未改性样品提高了503%。环境响应因子结果表明,三元复合水凝胶具有良好的碱性敏感性和盐响应能力,当pH>10时,保水率最高达到了1945.21%。当NaCl溶液浓度为16 mmol/L时,保水率最高达到了457%,且在40℃以上的高温环境体系,放置50 min时,其保水率能达到50%以上。改性水凝胶对高温、高盐、高碱地区的农业生产具有一定的指导意义。

H_6P_2Mo_9W_9O_(62)/Zn(BDC)(Bipy)_(0.5)复合材料催化合成3,4-二氢嘧啶-2(H)酮衍生物

采用水热法分别合成杂多酸H_6P_2Mo_9W_9O_(62)及有机金属骨架Zn(BDC)(Bipy)_(0.5),使用浸渍法合成H_6P_2Mo_9W_9O_(62)/Zn(BDC)(Bipy)_(0.5)复合材料,用该复合材料催化醛、乙酰乙酸乙酯和尿素通过Biginelli反应,乙醇作溶剂,合成6种3,4-二氢嘧啶-2(H)酮衍生物。通过IR、1HNMR、13CNMR确定其结构,通过m.p.确定其纯度。实验结果表明:固定醛用量为0.04 mol,n(醛)∶n(乙酰乙酸乙酯)∶n(尿素)=1∶1.4∶1.5,2.0 wt%H_6P_2Mo_9W_9O_(62)/Zn(BDC)(Bipy)_(0.5),反应温度为105℃,反应时间为60 min时,产物收率为40.1%~91.5%。