酚醛树脂对介孔碳孔结构及有序性的影响

以酚醛树脂为碳前体,三嵌段聚合物F127作为模板剂,采用溶剂挥发自组装法制备了有序介孔碳材料。采用凝胶渗透色谱测定了不同合成温度酚醛树脂的分子量;使用X射线衍射、透射电镜和N2吸/脱附等手段对有序介孔碳进行了表征。研究了合成酚醛树脂的温度对介孔碳孔径分布及有序性的影响。结果表明,随着合成酚醛树脂的温度从75℃升到95℃,介孔碳的有序性先增后减:酚醛树脂的合成温度为85℃时,所得介孔碳有较好的有序性,介孔孔容和比表面积分别为0.115cm3/g和127m2/g,平均孔径为3.41nm。     

制备工艺对酚醛树脂基炭分子筛性能影响

以工业酚醛树脂㈣为碳源,三嵌段聚合物F127作为模板剂制备炭分子筛材料。采用TG、SEM、FTIR和N_2-BET等表征手段对制备的炭分子筛进行了表征,研究了前驱体制备工艺对炭分子筛孔径分布的影响。结果表明,F127用量、搅拌时间、反应温度对炭分子筛孔径分布影响很大。在酚醛树脂与F127质量比1:1,反应温度45℃,搅拌时间6 h,800℃炭化条件下制备的炭分子筛孔径分布最为集中,BET比表面积和单点总孔容分别为716.59 m~3·g~(-1)和0.55775 cm~3·g~(-1)。     

碳化法制备酚醛树脂基微滤碳膜

以高含碳热塑性酚醛树脂为原料,通过碳化制备了酚醛树脂基微滤碳膜,考察了碳化条件,包括碳化终温、升温速率、恒温时间和保护气流速对膜的平均孔径、孔径分布和气体透量的影响. 对碳膜进行了CO2活化处理,考察了活化条件对碳膜性能的影响. 用热重分析考察了碳膜碳化失重,用泡点法测量了其孔径分布. 实验结果表明,随着碳化终温的升高,碳膜的平均孔径和气体透量均减小,当碳化终温从650℃升高到950℃时,碳膜的平均孔径从0.61 mm下降到0.54 mm,气体透量从1.84′10-5 mol/(m2×s×Pa)下降到1.14′10-5 mol/(m2×s×Pa). 350℃碳化温度得到的碳膜爆破强度最低,随着碳化温度的升高爆破强度增加. 升温速率、恒温时间和保护气流速对碳膜性能影响不大. 活化导致膜孔径变大,当CO2浓度从12.5%增加到50%时,碳膜的平均孔径从1.54 mm增大到1.96 mm,气体透量从7.0′10-5 mol/(m2×s×Pa)增大到1.68′10-4 mol/(m2×s×Pa).     

简易模板法制备有序介孔碳及其表征

目前制备有序介孔碳的方法工艺复杂、繁琐耗时,为了简化其制备工艺,缩短实验流程,本文提出一种不需要添加额外溶剂直接制备有序介孔碳的方法。以三嵌段共聚物F127为模板剂,自制低分子量酚醛树脂为碳前体,制备了具有二维六方结构的介孔碳。采用红外光谱对酚醛树脂和F127进行表征,研究了两者之间的作用力;采用X射线衍射、透射电镜和N2吸附/脱附等手段对介孔碳结构进行表征,研究了酚醛树脂的合成温度和模板剂用量对介孔碳结构的影响。结果表明酚醛树脂合成温度为70℃,F127：PF=1时,得到的介孔碳比表面积、孔容和孔径分别为490m2/g、0.41cm3/g和4.15nm。     

炭化工艺对酚醛树脂基碳分子筛性能的影响

以工业酚醛树脂为碳源,三嵌段聚合物F127为模板剂,制备碳分子筛。采用N_2吸附-脱附对制备的碳分子筛进行表征,研究炭化制备工艺对碳分子筛孔径分布的影响。结果表明,炭化温度、炭化时间和炭化升温速率对碳分子筛孔径分布影响较大。在炭化升温速率为1℃·min~(-1)、炭化温度800℃和炭化时间1 h条件下制备的碳分子筛孔径分布最为集中,BET比表面积716.59 m~2·g~(-1),单点总孔容0.557 75 cm~3·g~(-1),单点吸附微孔孔容0.301 81 cm~3·g~(-1)。     

无机铝源合成有序介孔氧化铝的影响因素研究

有序介孔氧化铝具有较大的比表面积、均匀且窄的孔径分布、有序的孔结构等特点,在多相催化反应及吸附分离过程中具有十分重要的应用价值,研究其合成及应用具有重要意义。以廉价的无机铝盐为铝源,结合模板剂,利用溶胶-凝胶法,通过改变模板剂的种类、老化时间和温度等影响因素,制备有序介孔氧化铝。采用多种测试技术对其结构进行表征,探讨不同反应条件对合成有序介孔氧化铝结构的影响规律。结果表明,以二正丙胺为模板剂,在40℃条件下老化48 h,可合成比表面积为324.80 m~2·g~(-1),孔容为0.62 cm~3·g~(-1),平均孔径为6.07 nm的介孔氧化铝,且孔径分布较窄,孔道有序性良好。     

白云石二次碳化法制备大立方体碳酸钙的研究

以河北省某矿山的白云石粉、二氧化碳、氯化铵为原料，采用二次碳化法制备大立方体碳酸钙，主要考察碳化温度、通碳速率、通碳量、陈化温度、陈化时间对方解石碳酸钙形貌的影响，并探究了碳酸钙的成型及生长过程和规律。结果表明：在40℃时通碳、通碳速率为50 mL/min、通碳200 s停止第一次通碳，升温陈化90 min后继续第二次通碳并陈化40 min后，可以制备得到大立方体方解石碳酸钙，纯度可达98%以上，白度可达95%～99%，其形貌规整，粒径较大，为15～20μm。此研究为储量丰富的碳酸盐矿物生产高附加值产品提供了新思路。     

最优炭化工艺下辣椒秸秆基活性炭的制备及表征

以辣椒秸秆制备活性炭,采用正交实验法,选取炭化温度、炭化时间、升温速率为影响因子,以比表面积、炭得率为评价指标确定最优炭化工艺,对最优条件下所制活性炭的孔结构及表面化学性质进行了表征.结果表明,最优炭化工艺为炭化温度400℃,炭化时间50 min,升温速率5℃/min;该条件下所制活性炭的炭得率为39.90%,BET比表面积为966.003 m~2/g,吸附总孔容为0.544 cm~3/g,平均孔径为2.252 nm;且表面存在丰富的孔隙结构及酚、醇羟基、羧基、醚基等官能团.     

干喷湿纺聚丙烯腈原丝的预氧化和碳化工艺

分析了预氧化时间、温度对预氧丝密度的影响,研究了预氧丝密度和牵伸率以及张力、碳化升温速率与碳纤维抗拉强度之间的关系。试验结果证明:延长预氧化时间和提高预氧化温度,预氧丝密度提高;当预氧丝密度为1.355 g/cm3时,得到的碳纤维的强度最高;当预氧化牵伸率为0.93%时,对应的碳纤维强度为4.84 GPa;在300℃/min低温碳化升温速率和1000℃/min高温碳化升温速率下,可以得到高性能碳纤维。     

有序介孔La_2Zr_2O_7的制备与表征

以F127作为模板剂,通过溶剂蒸发诱导自组装法合成了具有有序孔结构、孔径分布均匀的介孔锆酸镧,系统研究了不同煅烧温度处理后介孔锆酸镧的相组成、比表面积、孔径及其分布以及微观结构。结果表明,经800℃处理后,样品开始晶化,完全晶化的样品中仅含锆酸镧相。经600℃煅烧后样品的比表面积为136 m2/g,孔体积为0.14 cm3/g,800℃煅烧后比表面积仍达90 m2/g,显示出较好的热稳定性。随着煅烧温度进一步升高,样品的比表面积和孔体积急剧减小,表明该方法制备的介孔锆酸镧最高耐热温度为800℃。透射电子显微镜观察发现,400℃去除模板后,样品具有有序介孔结构,预期其具有较好的催化性能。     

Worm-hole structured mesoporous carbon monoliths synthesized with amphiphilic triblock copolymer

In the present work, mesoporous carbon monoliths with worm-hole structure had been synthesized through hydrothermal reaction by using amphiphilic triblock copolymer F127 and P123 as templates and resole as carbon precursor. Synthesis conditions, carbonization temperature and pore structure were studied by Fourier transform infrared, thermogravimetric analysis, transmission electron microscopy and N₂ adsorption–desorption. The results indicated that the ideal pyrolysis temperature of the template is 450 °C. The organic ingredients were almost removed after further carbonized at 600 °C and the mesoporous carbon monoliths with worm-hole structure were obtained. The mesoporous carbon synthesized with P123 as single template exhibited larger pore size (6.6 nm), higher specific surface area (747 m² g^?1), lower pore ratio (45.9 %) in comparison with the mesoporous carbon synthesized with F127 as single template (with the corresponding value of 4.9 nm, 681 m² g^?1, 49.6 %, respectively), and also exhibited wider pore size distribution and lower structure regularity. Moreover, the higher mass ratio of template P123/resole induced similar pore size, larger specific surface area and lower pore ratio at the same synthesizing condition. It was also found that the textural structure of mesoporous carbon was affect by calcination atmosphere.     

Ordered mesoporous carbon prepared from triblock copolymer/novolac composites

Ordered mesoporous carbon is synthesized by the organic–organic self-assembly method with novolac as carbon precursor and two kinds of triblock copolymers (Pluronic F127 and P123) as template. The hexagonal structure and a worm-hole structure are observed by TEM. The carbonization temperature is determined by TG and FT-IR. Characterization of physical properties of mesoporous carbon is executed by N₂ absorption–desorption isotherms and XRD. The mass ratios of carbon precursor/template affect the textural properties of mesoporous carbon. The mesoporous carbon with F127/PF of 1/1 has lager surface area (670 m² g^?1), pore size (3.2 nm), pore volume (0.40 cm³ g^?1), smaller microporous surface area (368 m² g^?1) and wall thickness (3.7 nm) compare to that with F127/PF of 0.5/1 (576 m² g^?1, 2.7 nm, 0.29 cm³ g^?1, 409 m² g^?1 and 4.3 nm, respectively). The mesoporous carbon prepared by carbonization at high temperature (700 °C) exhibits lager surface area, lower pore size and pore volume than the corresponding one obtained at 500 °C. The structure and order of the resulting materials are notably affected with types of templates. The mesoporous carbon with P123 as template exhibits worm-hole structure compare to that with F127 as template with hexagonal structure. In general, the pore size of mesoporous carbon with novolac as precursor is smaller than that with resorcinol–formaldehyde as precursor.     

血小板膜伪装介孔聚多巴胺纳米药物传递系统的制备及应用

以三甲基苯为模板剂,采用一锅法制备了具有介孔结构的聚多巴胺纳米粒子(MPDA).通过静电吸附负载盐酸阿霉素(DOX),通过血小板膜(PLTM)仿生伪装得到PLTM-DOX@MPDA纳米粒子.采用TEM、纳米粒度分析仪、BET和UV-Vis对纳米粒子的性质、形貌和粒径进行表征.结果表明,MPDA表面具有清晰的介孔结构,经PLTM包裹后的PLTM-DOX@MPDA平均粒径约为184 nm.MPDA孔径主要分布于45 nm左右,孔容为0.6232 cm3/g,比表面积高达61.181 m2/g,该介孔结构支持MPDA作为高效的药物传递系统.体外释药、体外细胞摄取和体外细胞毒性实验结果表明,PLTM-DOX@MPDA具有pH响应性控制药物释放,可以实现药物缓释,可以避免巨噬细胞吞噬并且主动靶向癌细胞,可显著提高DOX对人乳腺癌细胞(MDA-MB-231)细胞的杀伤作用.     

制备工艺对淀粉基碳分子筛性能的影响

以淀粉为碳源,F127为结构导向剂,通过KOH活化一步合成法制备系列碳分子筛,采用SEM、TG、FT-IR和N_2吸附-脱附等技术对原料和碳分子筛样品的结构、表面官能团和性能进行表征。结果表明,温度、F127与淀粉添加质量比和KOH浓度对碳分子筛样品的孔隙结构性能影响显著。在KOH浓度为0.75 mol·L~(-1)、m(F127)∶m(淀粉)=4∶3、搅拌时间12 h和反应温度45℃时制备的碳分子筛孔径分布集中,BET比表面积达1 228.972 5 m~2·g~(-1),单点孔容0.807 113 cm~3·g~(-1),单点微孔体积0.636 869 cm~3·g~(-1)。     

酚醛树脂基高度有序介孔炭材料的合成及其电容性

以碱性条件下制备出的A阶酚醛树脂为炭前驱体,三元嵌段共聚物P123及F127为介孔模板剂,采用乙醇溶剂蒸发诱导自组装与程序升温策略,制备出高度有序、比表面积达550.12 m2/g、孔容为0.385 4 cm3/g、平均孔径为3.97 nm的酚醛树脂基有序介孔炭材料。利用小角X射线衍射、扫描电镜、透射电镜、物理吸附及电化学性能测试等技术,研究了不同合成条件下得到的有序介孔炭材料的结构和电化学性能。结果表明,在6 mol/L KOH电解质溶液的三电极体系中,该优化有序介孔炭材料在1 A/g的电流密度下比电容可达146.5 F/g。     

介孔碳微球的合成及其应用研究进展

目前,介孔碳微球的合成主要有硬模板和软模板两种方法。硬模板是将碳前驱体通过溶剂挥发填充到已合成的球形介孔材料(硬模板)中,然后热处理掉硬模板得到介孔碳微球;软模板则是以三嵌段共聚物F127做为模板剂,酚醛树脂作为碳源在水热条件下制备出介孔碳微球。介孔碳微球在超级电容、锂离子电池、气体储存、生物医药等领域获得广泛应用,然而在摩擦润滑领域的研究却未见报道。结合本课题组的前期研究提出了其在摩擦领域的研究思路并展望了其应用前景。     

Influence of template on the structure of mesoporous carbon prepared with novalac resin as carbon precursor

Mesoporous carbons with different mesostructures were prepared with amphiphilic triblock copolymer PlurionicF127, Pluronic P123 and blends of F127/P123 as templates, and hexamethyltetramine cured novolac as precursors. When the mass ratio of template/novolac changed from 1/1 to 1/2, the ordering of mesoporous carbons reduced, and mesoporous carbons prepared with F127 as templates exhibited more excellent ordering compared to those prepared with P123 as templates. Increasing the content of P123 in the blends of F127/P123 induced the changes of mesophase and texture properties of resulting products. When the mass ratio of F127/P123 decreased from 0.67/0.33 to 0.33/0.67, the mesoporous carbons changed from two dimensional (2D) hexagonal to wormhole framework. Meanwhile, the mesoporous carbons exhibited similar surface area (about 574 cm²/g), and decreasing pore size (from 3.4 to 3.0 nm), total pore volume (0.37–0.32 cm³/g), d-spacing (8.3–7.7 nm) and wall thickness (5.5–3.9 nm). The 2D hexagonal mesoporous carbons prepared with F127 as templates exhibited larger specific surface area (670 m²/g), pore size (3.5 nm) and total pore volume (0.40 cm³/g), and slightly lower d-spacing (7.4 nm) and wall thickness (5.0 nm) compared to those prepared with blends of F127/P123 as templates.     

Synthesis of mesoporous carbon spheres with a hierarchical pore structure for the electrochemical double-layer capacitor

Mesoporous carbon spheres with hierarchical foam-like pore structures have been synthesized by a dual-templating strategy using phenolic resol as a carbon source, Pluronic F127 and spherical silica mesocellular foams (Si-MCFs) as the soft and hard template, respectively. The results show that the morphology and mesostructure of the silica template are faithfully replicated. The obtained mesoporous carbon material with spherical diameter size of ca. 3–5 μm exhibits hierarchical pore sizes (from ca. 3.5 to 60 nm), high specific surface area (1320 m²/g) and large pore volume (3.5 cm³/g). The carbon surface contains plenty of oxygen-containing groups, resulting in hydrophilic property for an electrode material. In addition, Pluronic F127 plays an important role in the synthesis for maintaining the foam-like mesostructure of the silica templates and faithful replication of the spherical morphology. The electrochemical measurements show that the hierarchically mesoporous carbon spheres as an electrochemical double-layer capacitor (EDLC) electrode present a long cyclic life, excellent rate capability, and high specific capacitance as ca. 208 F/g at 0.5 A/g in (2.0 M) H₂SO₄ aqueous solution. Its specific capacitance can still remain ca. 146 F/g at a high loading current density of 30 A/g with the retention of ca. 70%. Furthermore, this material also exhibits excellent capacitive performance in (C₂H₅)₄NBF₄/propylene carbonate electrolyte, and its specific capacitance is 97 F/g at loading current density of 0.5 A/g.     

模板法制备有序中孔炭材料及其性能

以SBA-15为模板,蔗糖为炭源,在不同的炭化温度下合成了不同比表面积的中孔炭材料。利用红外光谱(IR), 小角X射线衍射(XRD), 透射电镜(TEM),N₂吸脱附及循环伏安测试等技术考察了不同炭化温度对中孔炭材料形貌、比表面积、孔体积及比电容的影响。结果表明：最佳炭化温度为700℃,TEM观测表明,700℃炭化所制备的样品孔结构呈二维六角有序分布,N₂吸脱附测试表明,该样品的孔体积为1.88 cm³•g^-1,比表面积为1394 m²•g^-1,具有典型的中孔结构和集中的中孔分布,它的最可几孔径为3.4 nm;采用循环伏安测试电极及电容器的电化学行为,结果显示,该样品单电极在6 mol•L^-1的KOH电解液中,扫描速度为1 mV•s^-1时,比电容可达212 F•g^-1,是一种理想的超级电容器电极材料。