本文選題：中孔炭　切入點：水玻璃　出處：《華東理工大學》2015年碩士論文

【摘要】：中孔炭具有發(fā)達的孔結構、良好的導電性、優(yōu)良的熱穩(wěn)定性和化學性質,廣泛應用于吸附、分離、催化、電化學等領域。依據(jù)用途對中孔炭的孔結構和形貌進行調節(jié),可使中孔炭具有更好的應用性能。然而,現(xiàn)有的中孔炭制備技術生產成本昂貴、孔結構難以精確調控且制備出的中孔炭多為粉末狀或具有不規(guī)則外形,大大制約了其應用。因此,中孔炭的結構和形貌控制以及低成本制備研究具有重要的意義。本文以廉價的水玻璃為原料,通過控制水解條件,合成出具有不同尺寸的SiO2納米溶膠,并與間苯二酚-甲醛(RF)有機溶膠混合,經溶膠-凝膠過程得到有機-無機雜化復合凝膠,再經常壓干燥、炭化、酸洗,得到結構可控的中孔炭材料�？疾炝怂鉁囟�、水解時間和反應物組成對孔結構的影響。結果表明：中孔炭的孔隙反相復制于Si02凝膠網絡,其平均孔徑隨水解時間的延長或水解溫度的升高而增加,并在6-12 nm范圍內精細調控,而其總孔體積(1.1-2.3 cm3/g)可以通過改變炭和Si02前驅體的比例調節(jié)。進一步采用噴霧干燥技術,對液相復合溶膠進行霧化干燥,可規(guī)�；苽涑鲋锌滋课⑶�。通過控制水解條件(溫度、時間)、水玻璃的濃度和反應物組成,實現(xiàn)了材料的孔結構的精確調控。結果表明：二氧化硅作為模板,具有骨架支撐作用,能夠有效抑制聚合物微球在干燥和炭化過程中的體積收縮,有利于得到高孔隙率的中孔炭微球。中孔炭微球孔結構可通過調節(jié)水玻璃的水解時間、水解溫度和濃度,以及前驅體的組成進行調控。本工作所制備的中孔炭微球具有較高的比表面積(1000m2/g)、孔容(1-2.1 cm3/g)和比較窄的孔徑分布。最后研究了中孔炭微球對VB12的液相吸附行為。實驗結果表明：中孔炭微球具有極高的VB12平衡吸附容量(606mg/g),遠超一般的吸附材料。中孔炭微球的孔徑和孔容對VB12的吸附具有重要影響,隨著孔徑的減小或孔容的增大,平衡吸附量增大；隨著吸附溫度升高,平衡吸附量呈現(xiàn)先增加后減小趨勢。中孔炭微球對VB12分子的吸附平衡等溫線屬于⒈類型,滿足Langmuir吸附模型；中孔炭微球對VB12具有優(yōu)異的吸附動力學,其吸附歷程符合準二級動力學模型。
[Abstract]:Mesoporous carbon has developed pore structure, good electrical conductivity, excellent thermal stability and chemical properties. It is widely used in adsorption, separation, catalysis, electrochemistry and other fields. It can make mesoporous carbon have better application performance. However, the production cost of existing mesoporous carbon preparation technology is expensive, the pore structure is difficult to be accurately regulated, and the prepared mesoporous carbon is mostly of powder shape or irregular shape. Therefore, it is of great significance to study the structure and morphology of mesoporous carbon and its low cost preparation. In this paper, cheap sodium silicate was used as raw material, and hydrolysis conditions were controlled. SiO2 nanosol with different sizes was synthesized and mixed with resorcinol-formaldehyde (RF) organic sol. The organic-inorganic hybrid gel was obtained by sol-gel process, and then dried under atmospheric pressure, carbonized and pickled. The effects of hydrolysis temperature, hydrolysis time and reactant composition on the pore structure of mesoporous carbon were investigated. The results showed that the pore phase of mesoporous carbon was reproduced in Si02 gel network. The average pore size increases with the increase of hydrolysis time or hydrolysis temperature, and is controlled in the range of 6-12 nm, and the total pore volume can be adjusted by changing the ratio of carbon to Si02 precursor. The mesoporous carbon microspheres can be prepared on a large scale by atomizing and drying the liquid-phase composite sol. By controlling the hydrolysis conditions (temperature, time, water glass concentration and reactant composition), The results show that silica, as a template, can effectively inhibit the volume shrinkage of polymer microspheres during drying and carbonization. Mesoporous carbon microspheres with high porosity can be obtained by adjusting hydrolysis time, hydrolysis temperature and concentration of sodium silicate. The mesoporous carbon microspheres have high specific surface area of 1000m2 / g, pore volume of 1-2.1 cm ~ 3 / g) and narrow pore size distribution. Finally, the liquid phase adsorption behavior of mesoporous carbon microspheres for VB12 was studied. The results show that the mesoporous carbon microspheres have a very high VB12 equilibrium adsorption capacity of 606 mg / g / g, which far exceeds the normal adsorption materials. The pore size and pore volume of the mesoporous carbon microspheres have an important effect on the adsorption of VB12. With the decrease of pore size or the increase of pore volume, the equilibrium adsorption capacity increases, and with the increase of adsorption temperature, the equilibrium adsorption capacity increases first and then decreases. The adsorption equilibrium isotherms of VB12 molecules on mesoporous carbon microspheres belong to 1 type. The adsorption kinetics of mesoporous carbon microspheres on VB12 was excellent, and the adsorption process was in accordance with the quasi-second-order kinetic model.
【學位授予單位】：華東理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TQ127.11

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