为从分子尺度优化C-S-H微结构提供理论依据,采用模拟大体积混凝土内部变温历程的养护制度,运用29Si魔角旋转核磁共振(29Si MAS NMR)结合去卷积技术,研究了变温条件下Ba(OH)2掺量为1.0%时对水泥浆体C-S-H微结构的影响规律。结果表明:在...为从分子尺度优化C-S-H微结构提供理论依据,采用模拟大体积混凝土内部变温历程的养护制度,运用29Si魔角旋转核磁共振(29Si MAS NMR)结合去卷积技术,研究了变温条件下Ba(OH)2掺量为1.0%时对水泥浆体C-S-H微结构的影响规律。结果表明:在变温条件下掺加Ba(OH)2提高了水泥浆体中硅酸盐矿物水化程度,尤其在水化早期(3 d)时硅酸盐矿物水化程度增幅较大,进而使C-S-H结构中硅氧四面体二聚体数量增加,导致其C-S-H平均分子链长(MCL)显著低于纯水泥浆体,避免了纯水泥浆体在降温阶段出现C-S-H的MCL降低的现象。同时,掺加Ba(OH)2进一步降低了水泥浆体在变温过程下C-S-H中Al3+取代Si4+的程度。展开更多
Highly regioregular, head-to-tail coupled poly（3-octylesterthiophene） was synthesized by the Pd-catalysed oxidative C--H/C--H coupling polycondensation. The regioregularity of polymer products was confirmed by the 1...Highly regioregular, head-to-tail coupled poly（3-octylesterthiophene） was synthesized by the Pd-catalysed oxidative C--H/C--H coupling polycondensation. The regioregularity of polymer products was confirmed by the 1H-NMR technique. Furthermore, the effects of various reaction factors including polymerization temperature, solvents and catalysts etc. on the yield, molecular weight and structural regioregularity of the resultant polymers were systematically studied. The optical, electrochemical and crystallization properties of the resultant P3OET with different HT regioregularities in solution and film state were studied by UV-Vis and fluorescent spectroscopy, cyclic voltammetry and X-ray diffraction （XRD）, resepectively.展开更多
文摘为从分子尺度优化C-S-H微结构提供理论依据,采用模拟大体积混凝土内部变温历程的养护制度,运用29Si魔角旋转核磁共振(29Si MAS NMR)结合去卷积技术,研究了变温条件下Ba(OH)2掺量为1.0%时对水泥浆体C-S-H微结构的影响规律。结果表明:在变温条件下掺加Ba(OH)2提高了水泥浆体中硅酸盐矿物水化程度,尤其在水化早期(3 d)时硅酸盐矿物水化程度增幅较大,进而使C-S-H结构中硅氧四面体二聚体数量增加,导致其C-S-H平均分子链长(MCL)显著低于纯水泥浆体,避免了纯水泥浆体在降温阶段出现C-S-H的MCL降低的现象。同时,掺加Ba(OH)2进一步降低了水泥浆体在变温过程下C-S-H中Al3+取代Si4+的程度。
基金financially supported by the National Natural Science Foundation of China(Nos.21604063 and 51373122)China Postdoctoral Science Foundation(No.2016M591392)
文摘Highly regioregular, head-to-tail coupled poly（3-octylesterthiophene） was synthesized by the Pd-catalysed oxidative C--H/C--H coupling polycondensation. The regioregularity of polymer products was confirmed by the 1H-NMR technique. Furthermore, the effects of various reaction factors including polymerization temperature, solvents and catalysts etc. on the yield, molecular weight and structural regioregularity of the resultant polymers were systematically studied. The optical, electrochemical and crystallization properties of the resultant P3OET with different HT regioregularities in solution and film state were studied by UV-Vis and fluorescent spectroscopy, cyclic voltammetry and X-ray diffraction （XRD）, resepectively.
