炭化过程对聚丙烯腈基活性中空炭纤维性能的影响

聚丙烯腈(PAN)中空纤维在空气中250℃预氧化2 h后,在氮气气氛中炭化,得到PAN基中空炭纤维(PAN-CHF),再在二氧化碳气氛中活化,得到PAN基活性中空炭纤维(PAN-ACHF)。考察了炭化温度和炭化时间对PAN-CHF的收缩率、PAN-ACHF的收缩率、活化收率、比表面积和吸附性能的影响。结果表明:炭化温度为1 000℃时,PAN-CHF和PAN-ACHF的收缩率相同;炭化温度为900℃时,PAN-ACHF的比表面积最大,吸附性能最好,炭化时间对PAN-CHF和PAN-ACHF的收缩率影响不大,但活化收率随炭化时间延长呈上升趋势,比表面积先增后降,炭化时间为60 min时达到最大,其吸附量最大。     

预氧化时间对中空形态的聚丙烯腈基活性碳纤维性能的影响

聚丙烯腈(PAN)中空纤维在空气中250℃分别预氧化不同的时间,在N2气氛下于900℃进行碳化60min,随后用CO2气体在800℃活化40min,得到PAN基活性中空碳纤维(PAN-ACHF)。测定了PAN-ACHF对碘和亚甲基蓝的吸附量,考察了预氧化时间对PAN预氧化纤维的收缩率和芳构化指数以及对PAN-ACHF的活化收率和吸附性能的影响。     

热处理温度对炭纤维结构和性能的影响

在不同温度下对3K聚丙烯腈基炭纤维进行了高温处理，研究了热处理温度对炭纤维结构和性能的影响。试验结果表明，随着热处理温度的提高，炭纤维线密度下降，微晶层间距缩小，碳含量、微晶尺寸和拉伸模量得以提高。高温处理导致炭纤维拉伸强度发生较大损失，在本次试验中，在不同的热处理温度下，纤维强度下降的程度不同。     

KOH二次活化对PAN基活性碳纤维结构性能的影响

以Courtaulds公司的聚丙烯腈(PAN)纤维为原料,通过自主研发的碳纤维生产线制备出预氧化纤维,对其用连续化活化炉进行水蒸气物理活化,再经过KOH溶液浸渍,最后通过连续化活化炉进行化学活化,制备出具有高吸附性能的聚丙烯腈基活性碳纤维(PAN-ACFs)丝束。通过比表面积(BET)、红外光谱(FT-IR)、广角X射线衍射(WAXD)和碘吸附等表征测试手段研究了KOH对PAN-ACFs孔结构的影响。结果表明:逐步增加KOH的浓度,PAN-ACFs的碘吸附值明显增大,拉伸强度明显降低;当w(KOH)为15%,活化温度为850℃,活化时间为20 min时,所制备的PAN-ACFs具有相对较高的吸附性能、力学性能和碳化收率。     

活化温度对海泡石纤维自调湿性能的影响

用物理和化学方法对天然海泡石材料进行纤维剥离和活化处理,研究了海泡石纤维活化温度对其吸湿和放湿的影响。通过海泡石纤维质量损失、吸放湿实验,结合对海泡石纤维特殊晶体结构、比表面积和孔隙度的表征分析,综合评价海泡石纤维自调湿性能。结果表明：当活化温度在200～250℃之间,加热6h时,其孔隙度和比表面积最大,自调湿性能最为理想。从晶型结构分析,当温度超过250℃时,海泡石纤维孔径继续增大,比表面积减小,吸附性减弱;当温度超过300℃时,结晶水分解,使晶体发生改变,纤维孔出现塌陷、堵塞,吸附性急剧降低。     

聚丙烯腈基炭纤维组织结构表征与性能分析

采用扫描电子显微镜(SEM)、高分辨透射电子显微镜(HRTEM)、X射线衍射(XRD)、激光拉曼光谱(Raman)及化学分析法等测试技术对4种PAN基3K炭纤维(2种国产炭纤维、1种国外原丝国内炭化纤维、一种日本炭纤维)的表面形貌、组织结构及化学组成等方面进行了表征,并分析了材料的微观结构组织与宏观性能的关系。结果表明:相比日本炭纤维,国产炭纤维表面缺陷多、微观结构不完整、R值大、杂质含量多等因素决定了其具有较低的拉伸强度。     

聚丙烯腈基炭纤维生产含氰废气的治理方法

聚丙烯腈基炭纤维（PANCF）生产过程中产生大量有害废气,其中氰化氢（HCN）是剧毒物质,其治理日益受到重视。介绍了PANCF废气的治理方法,重点探讨脱除HCN的主要方法（吸附法、吸收法、直接燃烧法和催化燃烧法）及其原理、操作条件等。结果表明：催化燃烧法具有安全高效,节能环保,工艺简单,操作方便等优点,对处理含氰废气具有较大优势,是一项值得推广的环保治理技术。     

聚丙烯腈基中空炭膜的研究发展

概述了聚丙烯腈基活性炭纤维的制备和结构,制备条件对聚丙烯腈基中空纤维炭膜的影响,以及聚丙烯腈基中空纤维炭膜作为医用吸附剂的可行性。     

掺杂炭纤维对乙苯脱氢催化剂性能的影响

在氮气保护及程序控温条件下,制备了具有一定孔隙的炭纤维掺杂的乙苯脱氢催化剂。通过对比表面积、孔隙度的测定,发现微孔数量随炭纤维加入量的增加而增加,炭纤维催化剂得到了活化。催化剂的扫描电镜分析、侧压强度及抗拉强度测试证明,炭纤维使催化剂的机械强度明显提高。乙苯脱氢实验表明,苯乙烯选择性随炭纤维的加量增大;乙苯的转化率则存在最大值。考虑机械强度与催化活性,加入6%炭纤维的催化剂最佳。     

纺丝温度对中间相沥青炭纤维结构性能的影响

以萘催化合成中间相沥青(MP-1)和热缩聚法制备中间相沥青(MP-2)两种中间相沥青为原料,对其进行簇组成分析、偏光显微镜观察及红外光谱分析,研究其组成及结构.采用实验室气压式单孔纺丝装置在不同温度下对两种中间相沥青进行熔融纺丝,探讨纺丝温度对炭纤维结构及性能的影响.研究表明:MP-1低温获得无规结构,高温出现中心放射状边缘洋葱皮混合结构;MP-2随纺丝温度升高依次出现无规结构、准洋葱皮结构和洋葱皮结构.中间相沥青原料的性质影响着纤维截面结构随纺丝温度变化的规律.     

Influence of activation temperature on the properties of polyacrylonitrile-based activated carbon hollow fiber

In this work, polyacrylonitrile hollow fiber was oxidized, carbonized, and activated by carbon dioxide into activated hollow carbon fiber. The effects of the activation temperature on the characteristics of the resulting activated hollow carbon fiber, including the mechanical properties, the surface area, and pore size distribution, were studied. The results show that by activating for 40 min at 800°C, the mechanical properties was better, the surface area was larger, and the pore size was distributed in three ranges. Higher activation temperature led to the decrease in the mechanical strength, the increase in the burn-off degree of the surface, the reduce of the portion of micropores, and the greatly broadening the pore size distribution. Lower activation temperature can only produce pleading on the surface of the fiber instead of open pores, due to the milder attack of CO₂. Therefore, the characteristics of the activated hollow carbon fiber can be controlled by the activation temperature. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1331–1336, 1998     

Effects of activation temperature on the properties and structure of PAN‐based activated carbon hollow fiber

Polyacrylonitrile (PAN) hollow fibers were pretreated with ammonium dibasic phosphate, then further oxidized in air, carbonized in nitrogen, and activated with carbon dioxide. The effects of activation temperature of a precursor fiber on the microstructure, specific surface, pore‐size distribution, and adsorption properties of PAN‐based activated carbon hollow fibers (PAN‐ACHF) were studied in this work. After the activation process, the BET surface area of the PAN‐ACHF and surface area of mesopores in the PAN‐ACHF increased very remarkably and reached 1422 m² g^?1 and 1234 m² g^?1, respectively, when activation temperature is 1000°C. The adsorptions to creatinine and VB₁₂ of PAN‐ACHF were much high and reached 99 and 84% respectively. In PAN‐ACHF which went through the activation at 700°C and 800°C, the micropore filling mainly occurred at low relative pressures, multimolecular layer adsorption occurred with the increasing of relative pressure, and the filling and emptying of the mesopores by capillary condensation occurred at high relative pressures. But in PAN‐ACHF which went through the activation at 900°C, a mass of mesopores resulted in the large pore filling by capillary condensation. The dominant pore sizes of mesopores in PAN‐ACHF are from 2 nm to 5 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3778–3783, 2006     

Effects of activation time on the properties and structure of polyacrylonitrile‐based activated carbon hollow fiber

Polyacrylonitrile (PAN) hollow fibers were pretreated with ammonium dibasic phosphate, then further oxidized in air, carbonized in nitrogen, and activated with carbon dioxide. The effects of activation time of a precursor fiber on the microstructure, specific surface area, pore‐size distribution, and adsorption properties of PAN‐based activated carbon hollow fibers (PAN‐ACHF) were studied in this work. The BET surface area of PAN‐ACHF and surface area of mesopores gradually increase with activation time extending, and reach the maximum values, 780 and 180 m² g^?1, respectively, when fibers are activated at 800°C for 100 min. The adsorption ratio to creatinine changes little with activation time extending and all values over all activation time are above 90%. The adsorption ratio to VB₁₂ gradually increases with activation time extending before 60 min, and then becomes relatively constant from 60 to 100 min. The number of pores on the surface of PAN‐ACHF increases with activation time extending. The amount of mesopores in PAN‐ACHF made of fibers activated for different time increases with activation time extending and the dominant pore sizes of mesopores in PAN‐ACHF range from 2 to 5 nm. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 2565–2569, 2006     

Effects of the oxidation temperature on the structure and properties of polyacrylonitrile‐based activated carbon hollow fiber

Polyacrylonitrile (PAN) hollow fibers were pretreated with ammonium dibasic phosphate, oxidized in air, carbonized in nitrogen, and activated with carbon dioxide. The effects of the oxidation temperature of the PAN hollow fiber precursor on the microstructure, specific surface, pore size distribution, and adsorption properties of PAN‐based activated carbon hollow fiber (PAN‐ACHF) were studied. When PAN hollow fibers were oxidized at 270°C, because of drastic oxidation, chain scission occurred, and the number of pores within and on the surface of the resultant PAN‐ACHF increased, but the pores were just in the thinner region of the skin of PAN‐ACHF. The surface area of PAN‐ACHF reached a maximum when the oxidation temperature was 270°C. The adsorption ratios to creatinine were all higher than 90% at all oxidation temperatures, and the adsorption ratio to VB₁₂ reached a maximum (97%) at 230°C. The dominant pore sizes of the mesopores in PAN‐ACHF ranged from 2 to 5 nm. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 203–207, 2005     

The effects of carbonization temperature on the properties and structure of PAN‐based activated carbon hollow fiber

Polyacrylonitrile (PAN) hollow fibers were pretreated with ammonium dibasic phosphate and then further oxidized in air, carbonized in nitrogen, and activated with carbon dioxide. The effects of carbonization temperature of PAN hollow fiber precursor on the microstructure, specific surface, pore‐size distribution, and adsorption properties of PAN‐based carbon hollow fiber (PAN‐CHF) and PAN‐based activated carbon hollow fibers (PAN‐ACHF) were studied in this work. After the activation process, the surface area of the PAN‐ACHF increased very remarkably, reaching 900 m² g^?1 when carbonization is 1000°C, and the adsorption ratios to creatinine and VB₁₂ of ACHF were much higher than those of CHF, especially to VB₁₂. The different adsorption ratios to two adsorbates including creatinine and VB₁₂ reflect the number of micropores and mesopores in PAN‐ACHF. The dominant pore sizes of mesopores in PAN‐ACHF are from 2 to 5 nm. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2155–2160, 2005     

中空活性碳纤维概述

中空活性碳纤维以其独特的结构而具有比活性炭和活性碳纤维更优异的性能，本文概述了中空活性碳纤维的制备过程及其应用，并指出，其作为吸附储氢材料具有一定前景。     

Effects of oxidation time on the structure and properties of polyacrylonitrile‐based activated carbon hollow fiber

Polyacrylonitrile (PAN) hollow fibers were pretreated with ammonium dibasic phosphate, then further oxidized in air, carbonized in nitrogen, and activated with carbon dioxide. The effects of oxidation time of PAN hollow fiber precursor on the microstructure, specific surface, pore size distribution, and adsorption properties of PAN‐based activated carbon hollow fiber (PAN‐ACHF) were studied in this work. Both of specific surface area and adsorption ratio to VB₁₂ reach maximums when PAN hollow fibers are oxidized for 5 h in air. The adsorption ratios for creatinine are all higher than 90% over all oxidation time. After 5 h of oxidation, the number of pores on the surface obviously increases, and the pore size is uniform. After 7 h of oxidation, the number of macropores in PAN‐ACHF increases. The dominant pore sizes of mesopores in PAN‐ACHF range from 2 to 5 nm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

椰壳纤维制备活性炭纤维的研究

本文以椰壳纤维为原料,采用正交试验方法研究了(NHe)2HPO4作为活化剂,经预处理、炭化和活化过程制备活性炭纤维,其比表面积达到1268.1 m2.g-1,含有一定量的中孔孔结构,主要集中在2～4nm.通过对比分析,得出了各反应条件对反应产物性能的影响,并对活化机理进行了分析.