双氧水——硫酸法低硫可膨胀石墨的研究

研究双氧水－硫酸法制取可膨胀石墨的工艺，探讨了反应配比、温度、时间、水洗条件对可膨胀石墨膨胀容积的影响，开发出新型可膨胀石墨中硫的脱除剂ＳＣ。     

PEMFC用石墨/酚醛树脂复合板的膨胀石墨表面改性

提出采用膨胀石墨对石墨/酚醛树脂复合板进行表面改性,改性后复合板的体积电阻和接触电阻都有显著降低。考察了膨胀石墨的膨胀体积、膨胀石墨层厚度等因素对膨胀石墨改性复合板的接触电阻和体积电阻的影响。结果表明,膨胀石墨的膨胀体积是影响膨胀石墨改性复合板体积电阻和接触电阻的重要因素。随膨胀石墨层厚度增加,接触电阻先减小而后趋于不变。复合板中酚醛树脂含量越高,采用膨胀石墨表面改性对降低复合板的体积电阻和接触电阻的效果越显著。     

用高锰酸钾作氧化剂制备可膨胀石墨

探讨了用高锰酸钾作氧化剂制备可膨胀石墨时，高锰酸钾的浓度、浓硫酸和石墨的重量比、硫酸的浓度、反应温度、反应时间对可膨胀石墨膨胀容积的影响。其最佳参数：高锰酸钾的浓度为６％；浓硫酸和石墨的重量比为３：１；硫酸浓度为９８％；反应温度为５５℃；反应时间为２０ｍｉｎ。     

双氧水—硫酸法低硫可膨胀石墨的研究

研究双氧水—硫酸法制取可膨胀石墨的工艺，探讨了反应配比、温度、时间、水洗条件对可膨胀石墨膨胀容积的影响，开发出新型可膨胀石墨中硫的脱除剂ＳＣ。     

可膨胀石墨的制备

探讨了分别用过二硫酸铵及过氧化氢作氧化剂制取可膨胀石墨时,氧化剂的浓度、硫酸的浓度、浓硫酸与石墨的重量比、反应温度、反应时间诸因素对可膨胀石墨膨胀容积的影响,并得出最佳反应条件。     

微米可膨胀石墨的制备

以D50为0.99 μm的微米石墨为原料,采用KMnO4-HNO3-HClO4-HAc氧化插层反应体系制备可膨胀石墨.通过6因素5水平的正交实验,得出了影响反应体系的主要因素是冰乙酸用量、反应温度和硝酸与高氯酸比例.当反应工艺为:m(C)∶m(KMnO4)=1∶0.4,V(HNO3)∶V(HClO4)=1∶1,m(C)∶V(冰乙酸)=1∶1.5,反应温度为45℃,反应时间为110 min时,可以制得最大膨胀体积的可膨胀石墨.     

影响膨胀石墨体积的制备工艺研究

采用HClO4/H3 PO4/CrO3氧化插层体系制备低温可膨胀石墨,通过对反应物用量、反应温度及反应时间、水洗温度及水洗程度、干燥温度、膨胀温度进行研究,确定了膨胀石墨体积的影响因素.结果表明:反应物m(C)∶m(HClO4)∶m(H3PO4)∶m(CrO3)=1∶3.0∶1.5∶0.8,反应温度45℃,反应时间70...     

膨胀石墨的表观密度,孔隙率和吸附吸收特性

以煤油为介质测量膨胀石墨的表观密度，由所测密度值与浸泡时间的关系得出膨胀石墨对煤油的吸附吸收量随时间的变化曲线，并导出膨胀石墨最终表观密度、开放孔孔隙率和封闭孔孔隙率。     

膨胀石墨膨胀机理的研究

在进行石墨膨胀实验的过程中，发现压片后的膨胀石墨不能再次膨胀很大倍数，通过XRD研究得出，膨胀石墨仍具有石墨的结构，并且还发现鳞片石墨中灰分的含量越少膨胀体积越大，这些实验结果证明传统的膨胀机理不完善，由此推断出一个新的膨胀机理，石墨的膨胀不仅发生在层间，还发生在鳞片石墨灰分挥发后留下的空位，并对这一结论作了论证。     

马达加斯加可膨胀石墨的制备与研究

以马达加斯加提纯石墨为原料,分别以醋酸,硫酸,硝酸,高氯酸,磷酸,高锰酸钾为氧化插层剂,在药剂种类,药剂用量,反应时间,反应温度等条件进行单因素试验寻求以马达加斯加石墨为原料制备可膨胀石墨的最佳条件.得到的最佳条件为:石墨质量(g)∶高氯酸体积(mL)∶磷酸体积(mL)∶高锰酸钾质量(g)=3∶9∶2∶0.3,在50℃下反应30 min.可制得膨胀体积为350 mL·g-1的可膨胀石墨,分级后+0.300 mm石墨可制得膨胀体积为480 mL· g-1的可膨胀石墨.XRD和SEM分析证明确实有含氧酸根(H2PO4-,HPO42-,PO43-和ClO4-)的插入使石墨得以受热膨胀.     

Recovery of heavy oil from contaminated sand by using exfoliated graphite

Heavy oil was recovered from contaminated sand through capillary suction into exfoliated graphite with differentpacked densities by using model sands, alumina powders, with different particle sizes. For efficient recovery it was important to have an appropriate combination of average size of sand particles and packed density of exfoliated graphite. Pumping of heavy oil into exfoliated graphite occurs as a balance in an attracting capillary force between exfoliated graphite and sand, the former being stronger than the latter because of the hydrophobic nature of the surface of graphite.     

膨胀石墨对高分子吸附的研究

本文对膨胀石墨制备方法进行了研究,以及各种方法制得的膨胀石墨对油类物质及些有机物的吸附效果进行了比较。     

改性膨胀石墨对甲醛的吸附性能研究

对含甲醛的废气处理一般采用吸附法，本文以天然鳞片石墨、浓硫酸、浓硝酸、双氧水、重铬酸钾为原料，采用改进的二次氧化法制备膨胀石墨，并对所制得的膨胀石墨进行表面改性。运用改性后的膨胀石墨对甲醛进行静态和动态吸附实验，实验结果表明，改性后的膨胀石墨对甲醛气体的吸附能力有大幅度提高。研究了改性前后膨胀石墨孔结构的变化及其对饱和吸附量的影响，并对改性机理进行了初步探讨。     

Preparation and characterization of graphite nanosheets from ultrasonic powdering technique

Natural flake graphite was exfoliated into exfoliated graphite via an acid intercalation procedure. The resulting exfoliated graphite was a worm-like particle composed of graphite sheets with thickness in the nanometer scale. Subjecting it to ultrasonic irradiation, the exfoliated graphite was effectively further foliated into isolated graphite nanosheets. SEM, TEM, SAD, laser counting, and BET measurements revealed that the graphite nanosheets prepared with 10 h irradiation were about 52 nm in thickness and 13 μm in diameter. FTIR examination showed that there were oxygen-containing groups presented on the surface of the exfoliated graphite. This result substantiated the statement reported in the literature that acid treatment could result in oxidization of carbon bonds on graphite surface.     

Regenerated cellulose nanocomposites reinforced with exfoliated graphite nanosheets using BMIMCL ionic liquid

Green nanocomposites of regenerated cellulose/exfoliated graphite nanosheets films with low nanofiller loadings were prepared using environmentally benign 1-butyl-3-methylimidazolium chloride (BMIMCl) ionic liquid. X-ray diffraction revealed well developed intercalated nanocomposites. The tensile strength and Young's modulus of the prepared nanocomposites were increased by 97.5% and 172% respectively when 0.75 wt.% and 1 wt.% exfoliated graphite nanosheets were added. The results were validated using the Halpin–Tsai model. The exfoliated graphite nanosheets were unidirectionally aligned in the regenerated cellulose parallel to the surface of the nanocomposites as revealed by transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM). Also, the TEM and FESEM revealed uniform dispersion of the exfoliated graphite nanosheets and good interaction between the nanofillers and the matrix. The addition of the exfoliated graphite nanosheets enhanced the thermal stability and reduced the water absorption and diffusivity of the nanocomposites.     

膨胀石墨的化学制备法和影响其质量的因素

膨胀石墨作为新型炭素密封件材料广泛用于石油、化工、电力、冶金、医药、食品、机械等行业。介绍了用化学法制备的膨胀石墨的过程中石墨的粒度、酸化液配比、pH、膨胀温度对膨胀石墨质量的影响。     

饮用水源突发性柴油污染的吸附法应急处理模拟试验

通过室内模拟实验,研究了膨胀石墨对饮用水源水突发性柴油污染的应急消减性能。考察了振荡速率、水体pH、膨胀石墨投加量和水温对吸附效果的影响,测定了吸附等温线,对吸附规律进行了探讨。结果表明,膨胀石墨可快速高效地消减突发性柴油污染。在本研究条件下,振荡速率、水体pH和水温对柴油的吸附无显著性影响。当膨胀石墨投加量为5g/L时,历时5s即可将1 000 mg/L的柴油去除97%以上。等温吸附规律可用Freundlich模型较好的拟合,拟合得到的线性方程可为应急处理水源地突发柴油污染提供基础模型。     

Sorption and recovery of heavy oils using exfoliated graphite Part IV: Discussion of high oil sorption of exfoliated graphite

The correlation between sorption capacity for heavy oil with a viscosity of 0.004 kg/m s and pore volume measured by a mercury porosimeter was studied on exfoliated graphite samples with different bulk densities. Pore volume measured by using the conventional dilatometer (N-type cell), which gives information on the pore size from 0.004 to 4 μm, was too low to explain the sorption capacity measured. However, pore volume measured by a special dilatometer (U-type cell) for large pore sizes up to 600 μm was very closed to sorption capacity. Pore volume measured by this U-type cell showed a linear relation to sorption capacity of exfoliated graphite samples, of which the slope was the same value as the density of heavy oil used (860 kg/m³). Therefore, large pores, which are reasonably assumed to be inter-particle pores among entangled worm-like particles of exfoliated graphite, were responsible for the large sorption capacity of heavy oils. Intra-particle pores inside and cleavage-like pores on the surface of worm-like particles were assumed to assist the capillary pumping of heavy oil.     

Comparative evaluation of cement-matrix composites with distributed versus networked exfoliated graphite

Cement with distributed exfoliated graphite (isotropic) is made by incorporating exfoliated graphite in the wet cement mix; cement with networked exfoliated graphite (anisotropic) is made by compressing a dry mixture of exfoliated graphite and cement particles, followed by curing with water. The graphite layers in the latter are preferentially oriented in the plane perpendicular to the compression direction; the in-plane electrical resistivity is much lower than the out-of-plane resistivity and the loss tangent, storage modulus and loss modulus are much higher for out-of-plane flexure than in-plane flexure. The latter gives higher density, lower electrical resistivity, higher compressive strength and superior vibration damping than the former. Compared to plain cement, it gives higher density and higher compressive strength. In contrast, cement with distributed exfoliated graphite gives lower density and lower compressive strength than plain cement, though it gives lower resistivity and superior damping. Distributed exfoliated graphite is detrimental when silica fume is present. The high damping of cement with networked exfoliated graphite is attributed to the effective sandwiching of the network ligaments by the cement matrix (constrained-layer damping); the high density and compressive strength are attributed to the low porosity caused by the compression of the exfoliated graphite during composite fabrication.     

混酸插层制备膨胀石墨研究

对采用H2SO4-HNO3-KMnO4-H2O2混酸氧化插层体系制备膨胀石墨进行了研究,采用扫描电镜（SEM）、X射线衍射（XRD）、红外光谱（IR）和热重一差热法（TG-DTA）分析产物,并提出了氧化插层过程和机理。分析表明：插入剂的插入破坏了原有鳞片石墨层的紧密结构,使碳层间距增大,高温膨胀后,膨胀石墨呈蠕虫状或手风琴状蓬松结构,一个石墨蠕虫由许多微胞连接在一起组成,微胞之间呈现较大的狭缝裂开。氧化插层破坏了鳞片石墨原有的晶体结构,但是未破坏石墨的C—C键,20=29．5。处的特征峰是由石墨插层物结晶区引起的。可膨胀石墨片层。间存在SO4^2-、NO2阴离子插层物。可膨胀石墨在500℃之前的热失重和267℃附近较小的放热峰,均是由石墨插层物的气化、分解所致。