真空浸渍制备膨胀石墨基C/C复合材料及其甲醛吸附性能

以蔗糖为炭源,磷酸为活化剂,采用真空浸渍法经炭化、活化制得膨胀石墨基C/C复合材料.采用SEM、氮气吸脱附法、TG和TEM等测试手段,研究了磷酸/蔗糖质量比(Xp)、蔗糖浓度对复合材料孔结构和比表面积的影响,利用FTIR和Boehm滴定法对复合材料表面的化学官能团进行表征,并考察了C/C复合材料对甲醛的吸附能力.结果表明:膨胀石墨基C/C复合材料含有大量的微孔、一定量的介孔和大孔,表面含有丰富的含氧官能团,有利于对甲醛极性分子的吸附.在Xp=1.0、蔗糖溶液浓度为30％(质量分数)时所制得的膨胀石墨基C/C复合材料比表面积最高,达到2112m2/g,孔容为1.08 mL/g,其对甲醛的吸附量为854mg/g,较同工艺制备的活性炭提高了26.9％.     

聚苯并噁嗪基硫,氮共掺杂多孔炭的制备及其对CO_2的吸附性能（英文）

采用原位合成法,以对氰基苯酚、硫脲和甲醛为原料制备了聚苯并噁嗪基树脂,经炭化、活化得到相应的含硫,氮共掺杂的多孔炭。对样品的物理结构和表面化学性质进行了表征,结果表明活化后活性炭比表面积为1 512~2 385 m~2g~(-1),孔结构以微孔为主,且含有一定硫,氮元素。在1 bar和0、25℃条件下,未加造孔剂600℃活化样品的CO_2的吸附容量最高分别为6.96 mmol g~(-1)、4.55 mmol g~(-1),且具有一定的选择性和良好的循环稳定性。通过对CO_2吸附热及酸化实验分析,发现吸附过程同时存在物理吸附和化学吸附,且以有效的微孔结构物理吸附为主,硫/氮官能团的化学吸附为辅。     

真空浸渍制备膨胀石墨基C/C复合材料及其甲醛吸附性能

以蔗糖为炭源, 磷酸为活化剂, 采用真空浸渍法经炭化、活化制得膨胀石墨基C/C复合材料。采用SEM、氮气吸脱附法、TG和TEM等测试手段, 研究了磷酸/蔗糖质量比(X_p)、蔗糖浓度对复合材料孔结构和比表面积的影响, 利用FTIR和Boehm滴定法对复合材料表面的化学官能团进行表征, 并考察了C/C复合材料对甲醛的吸附能力。结果表明: 膨胀石墨基C/C复合材料含有大量的微孔、一定量的介孔和大孔, 表面含有丰富的含氧官能团, 有利于对甲醛极性分子的吸附。在 X_p=1.0、蔗糖溶液浓度为30%(质量分数)时所制得的膨胀石墨基C/C复合材料比表面积最高, 达到2112 m²/g, 孔容为1.08 mL/g, 其对甲醛的吸附量为854 mg/g, 较同工艺制备的活性炭提高了26.9%。     

低浓度酸碱改性竹质活性炭对甲醛吸附性能的研究

甲醛作为室内空气的主要污染物之一,对人类的健康造成极大的危害.能否有效去除甲醛已成为人们关注的热点,而吸附法被认为是一种去除甲醛的重要方法.本研究采用低浓度的硝酸、草酸、双氧水和氢氧化钠于常温下浸渍处理竹质活性炭,利用环境扫描电子显微镜(E-SEM)、比表面积分析仪(BET)、傅里叶变换红外光谱(FTlR)和X射线光电子能谱(XPS)对改性前后的活性炭形貌、孔隙特征和表面官能团进行表征,并运用静、动态甲醛检测分析装置评价改性后的竹质活性炭对甲醛的吸附效果.结果表明,与未处理竹质活性炭相比,四种改性处理的竹质活性炭样品表面都有不同程度的蚀刻和皱缩,微孔数量均有不同程度的增加,但氢氧化钠改性竹质活性炭平均孔径为1.89 nm,小于未处理竹质活性炭孔径.改性前后竹质活性炭的FTlR特征吸收峰的峰形没有明显变化,只是峰强有所差异;XPS结果表明改性后竹质活性炭的含氧量均有所增加;改性活性炭对甲醛的去除能力明显提高了,其中硝酸改性竹质活性炭性能最好,主要原因是硝酸改性活性炭表面羰基和酯基的协同作用增强,提高了活性炭的极性,有利于对极性甲醛分子的吸附.     

活性炭表面改性及其对CO_2吸附性能的影响

采用硝化-还原法对高比表面积活性炭进行改性以提高其对CO2的吸附性能。利用氮吸附、FT-IR、元素分析、XPS等方法对改性前后的样品进行表征,并通过高压吸附装置测试CO2吸附性能。结果表明,改性样品对CO2的吸附量在室温下和319.15K下分别为17.72mmol/g和14.01mmol/g,比原样分别提高了49%和70%(单位比表面积吸附量的增加幅度),这可能与改性样品的表面连接了碱性较强的伯氨基等含氮官能团有关。改性样品经4轮缓和条件下的吸附-脱附循环后,吸附量未明显下降,表明改性样品仍以物理吸附为主。     

超声引入酸浸渍过程对活性炭性能的影响（英文）

在磷酸法制备活性炭的浸渍阶段引入超声,研究超声浸渍对活性炭孔结构、微观形貌、表面官能团、碘值和亚甲基蓝值的影响。结果表明,超声浸渍能够增大活性炭的比表面积、总孔容、微孔孔容、中孔孔容、极微孔孔容、碘值和亚甲基蓝吸附值,但长时间超声浸渍并无必要。最佳超声浸渍条件为:在45 min的总浸渍时间内引入5 min超声浸渍。在该条件下制得的活性炭比表面积达1 504 m~2/g,超过了文献中生物质基磷酸法活性炭的诸多相应值。另外,与静置浸渍相比,超声浸渍使制备最高碘值样品所需的总浸渍时间减少了85%。     

高温热处理对活性炭纤维微孔及表面性能的影响

研究了1173K高温改性处理对沥青基活性炭纤维吸附性能、孔径分布、微孔结构和表面化学的影响。低温(77K)N2吸附结果表明热处理后活性炭纤维比表面积略有下降，通过密度函数理论解析活性炭纤维全孔范围的孔分布得出活性炭纤维表面孔径大于1．0nm的微孔明显减少，微孔孔径更加集中于0．5nm～1．0nm，从而提高了活性炭纤维的碘吸附值。X射线衍射分析表明活性炭纤维是乱层石墨结构，热处理使活性炭纤维类石墨微晶碳层面的层间距下降，X光电子能谱分析表明热处理后活性炭纤维表面的含氧官能团C=O和COOH的含量变化不大，而呈碱性酚羟基C—OH含量的明显下降使活性炭纤维表面碱性降低。     

活化前铵盐处理对活性炭纤维吸附甲烷的影响

以沥青基炭纤维为原料，采用铵盐溶液对炭纤维浸渍处理、(H2O C02)活化的方法制备活性炭纤维，研究了铵盐浸渍对活性炭纤维甲烷吸附性能的影响。结果表明：铵盐预处理对提高活性炭纤维比表面积、孔容和活化产率有明显效果，是一种较好的预处理液。经铵盐处理得到的活性炭纤维较未处理活性炭纤维的甲烷吸附量高，但吸附量增加幅度小于比表面积和孔容的增加幅度。活性炭纤维的甲烷吸附量与微孔的孔径分布密切相关。     

竹基活性炭的煅烧-铵盐复合改性及表征

采用煅烧-铵盐复合改性方法制备了室温甲醛去除用竹基活性炭，并运用热重分析仪(TG-DTG)、X射线衍射仪(XRD)、扫描电子显微镜(SEM)、傅里叶红外光谱仪(FT-IR)、N₂吸附脱附仪等分析了复合改性对样品热稳定性、组织结构、比表面积和表面官能团的影响规律。结果表明：经煅烧-铵盐复合改性的竹基活性炭样品由非晶体组成，样品表面富含羟基、■、C—H或O—H等官能团，样品中含有大量的介孔、大孔等，其比表面积、孔容分别为164.21m²/g、0.1363mL/g,分别是未改性样品的195.49倍、10.65倍，从而使样品的室温甲醛去除率达到97.21%,比未改性样品增加了46.99%。煅烧-铵盐复合改性有利于改善竹基活性炭的孔结构、表面性质等，从而提高其室温甲醛去除性能。     

超声预处理对活性炭材料结构的影响及其表征

对活性炭(AC)进行超声预处理,通过正交实验评价超声功率、超声温度和超声时间三个因素对活性炭材料结构的影响。利用比表面积及孔径分析仪(BET)、场发射扫描电子显微镜(SEM)、碘吸附值测试,表征活性炭材料的微观形貌及吸附性能;利用傅里叶红外光谱法(FTIR),表征活性炭材料表面官能团。结果表明,超声温度50℃,超声功率140W,超声时间30min为最佳预处理条件。各因素对活性炭性能影响大小依次为功率温度时间。在该条件下制备出的活性炭比表面积为1161.6m2/g,与原样相比提高了11.2%;其表面及孔隙变得光滑干净,微孔体积和总孔容变大;活性炭表面官能团种类变化不大,酸性含氧官能团增多。活性炭材料经超声预处理后,性能得到改善,该结果为后期活性炭的应用研究提供参考。     

Effect of activated carbons modification on porosity, surface structure and phenol adsorption

The primary objective of this work was the examination of modified activated carbons with tailored adsorption capacity properties. Production of activated carbons with desired properties was accomplished by modification of surface functional groups and introduction of acidic/basic properties. Modification of an activated carbon was performed using partial oxygen gasification, nitric acid treatment, urea impregnation followed by pyrolysis and pyrolysis in a urea saturated stream. The surface properties of the produced samples were estimated by the multibasic titration method of Boehm and by the CO/CO2 gas evolution profiles, while pore structure development was measured by the N2 and CO2 gas adsorption isotherms. Oxygen gasification resulted in samples with surface area slightly lower that the raw activated carbon; the introduction of surface functional groups depended upon the severity of the treatment: carbonylic and phenolic type groups were introduced in all partially gasified samples, while low temperatures and short reaction times enhanced the basic character of the carbon. However, nitric acid treatment resulted in the introduction of high nitrogen amounts in the samples, the reduction of surface area and the development of a surface containing carboxylic, lactonic, phenolic and carbonylic groups with negligible HCl neutralization capacity. Treatment of activated carbon by urea supported the formation of basic groups and carbonyls. The presence of surface functional groups affected the adsorption capacity of the produced samples for the removal of specific pollutants such as phenols. Urea treated samples with a basic character and high nitrogen content presented the highest phenol uptake capacity; nitric acid treated carbons and oxygen gasified samples presented an acidic surface functionality and a low phenol adsorption capacity. The beneficial role of nitrogen on phenol adsorption was attributed to adsorbate-adsorbent interactions.     

硝酸和硝酸铈铵协同氧化改性木质活性碳纤维

采用0.005~0.050 mol/L的硝酸铈铵,协同1.0~7.0 mol/L的硝酸,在23~83 ℃条件下,对木质活性碳纤维(WACF)浸渍5 h进行氧化改性.通过 XPS、RAMAN、水吸附和汞吸附表征其表面和结构性能.结果表明,改性后 WACF的氧/碳比平均值为0.160,酚基和醇基含量提高,羧酯含量与氧化强度总体成反比.样品表面石墨化程度降低,样品芯部的石墨化程度提高.协同改性后,WACF孔体积降低,水吸附的比表面积显著提升.WACF对汞的吸附能力和水吸附比表面积与氧原子浓度呈线性关系.硝酸可以增加官能团含量,对结构影响较小.硝酸铈铵在增加官能团含量的同时,对结构和孔径有一定调控作用,对不同直径的吸附对象有一定的选择性,拓展了 WACF的应用范围.     

利用铈盐改性修饰活性炭纤维结构

利用硝酸铈铵对活性炭纤维进行了化学改性。研究了铈盐改性前后活性炭纤维的微观结构和表面化学结构的变化。结果表明，活性炭纤维经铈盐处理后，比表面积降低10％～20％左右，微孔孔径分布没有发生明显的变化，表面氧含量从原子分数11％提高至25％，使活性炭纤维表面形成更多的高价态含氧基团。并通过X射线光电子能谱和热重-红外联用的分析结果相结合，较为详细地、定量地分析了活性炭纤维表面的含氧基团。结果表明，利用热重一红外联用技术对活性炭纤维表面含氧基团的种类及其相对量分析结果与基于X射线光电子能谱的C1s分峰结果定量分析基本一致，两种结果可互为验证。     

H-K法研究ACFs的微结构

ＡＣＦｓ的吸附性能主要取决于比表面积和孔隙结构。在不同相对压力下的吸附行为对应不同的孔隙结构。在一定范围内微孔是决定吸附能力大小的重要因素。以Ｎ２吸附等温线为依据,采用Ｈ－Ｋ法考察了不同比表面积ＡＣＦｓ在微观结构以及吸附 的差异。     

炭纤维生物膜的形成机制——I、炭纤维表面特性对微生物固着化的影响

采用对比方法，借助化学分析、表面形态分析及生物相容性表征技术等系统地研究了以活性炭纤维、表面改性活性炭纤维作为细胞固着化载体的表面特性及对微物固着的影响。重点考察了纤维表面官能团、比表面积、润湿性等表面特性对微生物固着化的影响。研究结果表明：（1）炭纤维表面的吸附特性对微生物的初期固着起着重要的作用，具有高比表面积的活性炭纤维更易于微生物固着并挂膜。（2）炭纤维表面润湿性与某些酸性官能团的适量增加，有益于载体表面微生物的固着。（3）炭纤维尤其是活性炭纤维较市售有机高分子材料具有更加优异的生物相容性，前者的微生物固着化速率是后者的4倍－16倍。     

活性炭的双氧水表面改性及其吸附二氧化硫性能研究

目的 制备武器装备贮存微环境用单组分的二氧化硫吸附材料。方法 采用双氧水对椰壳活性炭进行表面改性,研究改性活性炭孔隙结构、表面化学性质的变化及其对二氧化硫吸附性能的影响。结果 活性炭存在微孔和中孔,改性后活性炭比表面积略有增加,平均孔径减小。双氧水与活性炭反应起到刻蚀作用,在活性炭表面产生了纳米尺度的网孔结构,降低了活性炭表面碳微晶有序程度,同时双氧水与活性炭反应时起到了氧化作用,提升了活性炭表面氧元素和含氧官能团含量。体积分数为20%的双氧水改性活性炭的吸附容量最高,达到154.15 mg/g,约为改性前的5倍。结论 双氧水对活性炭经表面改性后,产生了纳米尺度的孔隙,并提升了活性炭表面含氧官能团,在两者协同作用下显著提升活性炭对SO₂吸附性能,具有良好的装备应用前景。     

Static Adsorption of Xenon on ACF at 257K

The static adsorption of xenon on active carbon fiber(ACF) at 257K was measured with ASAP2010 specific surface area and pore diameter distribution instrument by changing the working gas from nitrogen to xenon.Compared with grain activated carbon(GAC),the results were as follows(1)The adsorption performance of Viscose-based ACF(VACF-As)was the best among all absorbents tested.VACF-A3 was the superior xenon absorbent.The performance of pitch-based ACF(PACF-Cs)approached that of GAC,(2) Due to the difference of aperture distribution ,the adsorption performances of ACF with different radices were different under the same experiment conditions even though the specific surface area was similar,(3)There were some differences of adsorptive capacity among ACF absorbents which had the same radic,however there was not definite relationship between their specific surface area and adsorptive capacity,(4)The adsorption of xenon on all kinds of ACF agrees with Langmuir equation.(5)The adsorptiov curves can be fitted with a binomial equation.     

Structure and antibacterial activity of silver-supporting activated carbon fibers

In this paper, several kinds of silver supporting activated carbon fibers (ACF-Ag) were prepared by the reduction adsorption on activated carbon fiber (ACF) activated with steam or H₃PO₄ using sisal, viscose and pitch fiber as precursors. Their pore structure and surface chemistry were characterized using nitrogen adsorption, XPS, WXRD and ICP quantitative analysis. Their antibacterial activities were tested. The results showed that metallic silver particle in micron or nano-scale size could be easily and dispersedly supported onto the surface of ACF using reduction property of ACF without largely decreasing their specific surface area. The ACF-Ag showed strong antibacterial activity against Escherichia coli and Staphylococcus aureus. The antibacterial activity has closed relationship with the precursors, the method of activation, silver content and the specific surface area of the ACFs. Generally, higher silver content and higher specific surface area provide the materials stronger antibacterial activity. ACF activated with phosphoric acid, due to the presence of certain amount of organic phosphoric groups on the surface, showed stronger antibacterial activity than those activated with steam. The antibacterial materials can be easily regenerated without decreasing their antibacterial activity and without releasing large amount of silver from the solid phase.     

A new method for preparing hydrophilic-activated carbon through ester hydrolysis in an alkaline environment

Hydrophilic-activated carbon was prepared by ester hydrolysis reactions, and was characterized by surface area analysis, Fourier transform infrared spectroscopy, scanning electron microscopy energy dispersive X-ray spectroscopy, and X-ray diffraction. Hydrophilic groups that were introduced on activated carbon surface through ethyl acetate hydrolysis in an alkaline environment were more efficient than those introduced with sodium acetate. During adsorption, the hydrophilic groups on modified activated carbon surface bound with water molecules through H-bonding and increased the adsorption capacity of water vapor. The adsorption isotherms of water vapor were well fitted by the Do model. Water molecules generated larger water clusters around the functional groups at 303 and 313 K. In addition, water desorption from the samples was analyzed by thermogravimetry. Water molecules that were hydrogen-bonded to functional groups exhibited higher thermal stability than those adsorbed in the micropore of activated carbon. Besides, the process of sodium acetate formation on the surface of modified activated carbon was discussed.