摘要
高效合成和功能性基团的引入是当前有机微孔聚合物材料研究的热点.采用强质子酸催化的腈基三聚环化反应,室温合成制备了一系列带有不同取代基的芴基共价三嗪骨架聚合物(FCTF1~FCTF3),系统研究了取代基的变化对所得材料光学性能、多孔性能及CO2吸附能力的影响.其中乙基取代的聚合物FCTF2具有最高的BET比表面积(621m2/g)和CO2吸附能力(1.8 mmol/g,273 K/1.1 bar).该研究有助于加深对有机微孔聚合物结构与性能关系的理解,对该类材料的分子设计有借鉴意义.
Efficient synthesis and the introduction of functional group are the focus of current research on microporous organic polymers(MOPs). In this report, a series of new covalent triazine-based framework polymers(CTFs) based on fluorene with different substituents(FCTF1~FCTF3) has been synthesized using trifluoromethanesulfonic acid(TFMS) catalyzed cyclotrimerization reactions at room temperature. The chemical structures of the polymers were confirmed by FTIR and elemental analysis. In the FTIR spectra, the nearly absence of peaks at around 2220 cm-1 along with the emergence of strong triazine absorption bands around 1500, 1360 and 800 cm-1 indicated qualitatively a high degree of polymerization. Thermogravimetric analysis(TGA) under nitrogen atmosphere revealed a high thermal stability with 5% weight loss at temperature up to 364(FCTF1), 452(FCTF2) and 238 ℃(FCTF3). The solid UV-Vis spectra showed that the polymers could all absorb light from UV to visible light region. In the photoluminescence measurement, FCTF1~FCTF3 exhibited bright blue fluorescence with maximum emission wavelengths at 437 nm, 455 nm and 439 nm respectively. The specific surface areas of the polymers changed dramatically according to the substituent attached to the fluorine unit, with BET surface areas changing from nearly nil(FCTF3) to 621 m2/g(FCTF2) when the substituent changed from butyl to ethyl. Pore size distributions were calculated using nonlocal density functional theory(NL-DFT) and porous polymers FCTF1 and FCTF2 showed main pore sizes in the micropore region. CO2 adsorption capacities of the polymers were also measured and FCTF1 and FCTF2 showed high CO2 uptake of 1.7 and 1.8 mmol/g respectively at 273 K/1.1 bar. The isosteric heats of adsorption were calculated from the CO2 isotherms measured at 273 and 298 K. FCTF1 and FCTF2 showed adsorption heats of 26.4 and 22.7 k J/mol respectively at the zero coverage, indicative strong binding affinity of the polymers with CO2. To the best of our knowledge, this is the first report on the s
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
2015年第6期629-633,共5页
Acta Chimica Sinica
基金
国家自然科学基金(No.21404074)
教育部博士点基金(20130181120054)
高分子材料工程国家重点实验室自主课题(Sklpme2014-3-10)资助~~
关键词
有机微孔聚合物
芴
共价三嗪骨架聚合物
多孔性
CO2吸附
microporous organic polymers
fluorene
covalent triazine-based frameworks
porosity
CO2 adsorption
