多聚磷酸对沥青表面自由能的影响

 为研究多聚磷酸的加入对于沥青表面自由能的影响,在4种 SHRP(Strategic highway research program)沥青中加入不同剂量的多聚磷酸进行改性,得到多聚磷酸改性沥青,采用接触角法确定了各沥青样品的表面自由能。结果表明,多聚磷酸改性沥青表面自由能的变化与沥青原样的沥青质含量有关,低沥青质含量的沥青在加入多聚磷酸后,其表面自由能随多聚磷酸加入量的增加呈先上升后下降的趋势;而沥青质含量高的沥青,在加入多聚磷酸之后,其表面自由能随多聚磷酸加入量增加的变化基本呈下降趋势。     

不粘轮乳化沥青黏层不粘轮效果试验方法研究进展

不粘轮乳化沥青黏层作为一种高性能黏层用于沥青路面新建与养护工程,提升了黏层施工质量和沥青路面耐久性。不粘轮效果试验是不粘轮乳化沥青黏层关键评价方法。为了提升现有不粘轮效果试验方法的准确性、适用性,汇总分析了常见的不粘轮效果试验方法(指压法、黏聚力仪法、负荷轮法、车辙仪法、滚轮法、DSR法)的优缺点。另外,从加载方式、加载压力、加载时间(次数)、试验过程温度控制、黏层表面接触材质等试验参数考虑,提出针对不粘轮效果试验方法的研究建议,为今后研究和制定不粘轮效果试验标准方法提供参考。     

水溶性降黏剂和油溶性降黏剂对油水界面膜的影响

为揭示水溶性和油溶性降黏剂对采出液破乳脱水的影响,研究了聚氧乙烯醚型水溶性降黏剂（SH）和不饱和酸酯聚合物型油溶性降黏剂（SL）对胜利油田陈庄稠油采出液破乳的影响,通过扩张流变法和扫描电镜从界面膜角度分析了两种降黏剂对稠油采出液稳定性的影响机理。结果表明,SH浓度由0 增至3 g/L 时,采出液油水界面扩张模量由20.09 mN/m降至3.02 mN/m,脱水率由47.62%增至66.67%,界面黏性模量和弹性模量降低,相角由18.43o增至29.43o,SH分子可增大沥青质之间及胶质与沥青质之间的距离,使界面膜强度减小。SL 浓度由0增至3 g/L 时,油水界面扩张模量由20.09 mN/m增至34.76 mN/m,脱水率由47.62%降至6.80%,界面黏性模量降低的同时弹性模量增加,相角由18.43o降至9.83o,SL可增强沥青质分子之间的相互作用,沥青质表面呈现“鱼鳞”形状的规则排布,结构紧密,界面膜强度增强。SH有利于稠油采出液破乳脱水,而SL不利于稠油采出液破乳脱水。图12 参14     

油藏润湿性表征新方法

原油粘附在油藏岩石表面,影响了一次、二次和三次采油的采收率。文献中所报道的各种润湿性测定力法,有的未考虑粘附对所测接触角的影响,有的只说明有粘附作用或无粘附作用,而未具体测定对接触角的影脑。本新建方法首次考虑了在油藏温度和减压力条件下,粘附作用对测定接触角的影响。新建方法是用浮力排驱油珠和矿物是体表面之间的水膜,在老化达到吸附平衡后,测定前进接触角和后退接触角。其做法是：实验开始,在两块平行放置的晶体表面上各滴一滴油珠,超过预先确定的老化时间后,将油珠合二为一,由此命名为双滴双晶方法（DDDC）。文中所测的前进角和后退角照片本文（略）展现了水湿、中间润湿和油体系各自三相接触线（TPCL）的特征,解决了常规方法接触角测定与实际偏差大,不能测再生接触角等问题。迄今公开发表的用接触角表征油藏润湿性方法中,唯有DDDC法能定量反应粘附对所测接触角的影响,并能重复测定接触角。     

两亲聚合物ICJN对原油的乳化与降黏作用研究

为获得适合稠油开采的驱油剂,设计合成了两亲聚合物驱油剂体系ICJN。采用扫描电镜（SEM）、荧光显微镜、旋滴界面张力仪、接触角测定仪、石英晶体微天平和微观驱油模型实验对ICJN 在溶液中的聚集形态及其对稠油的乳化、分散能力和降黏性能、驱油性能进行了研究。结果表明：浓度1000 mg/L 的ICJN溶液可降低油水间界面张力至10^-1 mN/m 数量级;与水解度25%、黏均相对分子质量1800 万的普通部分水解聚丙烯酰胺HPAM相比,ICJN 具有较强的增黏能力;对于黏度上万的稠油,在油水体积比为1∶1 条件下,浓度1200 mg/L 的ICJN 可以使混合油水体系黏度降至100 mPa·s 以下,降黏率在95%以上;ICJN 具有较强的洗油能力,以沥青质模拟原油重质组分,在SiO₂芯片表面吸附沥青质,浓度1200 mg/L的ICJN溶液作为流动相,解吸附40 min后沥青质的吸附量从489.2 ng/cm²降至207.4 ng/cm²,吸附层厚度从4.7 nm 降至3.1 nm。ICJN 溶液既可以通过扩大波及体积驱油,又可依靠较低的油水界面张力从岩石表面乳化分散剥离原油。微观驱油实验结果显示,浓度1000 mg/L 的ICJN 体系的驱油效果明显优于等浓度的HPAM体系和1000 mg/L HPAM+3000 mg/LAOS体系。图24 表4 参10     

多孔介质润湿反转为优先气湿及气体润湿性

理论和实验证实凝析气藏多孔介质表面润湿性由液湿转变为优先气湿可显著提高气井产量,且气湿程度对气井产量影响较大.但是目前,气体润湿性缺少定量评价方法,无法给出气湿性定量结论.通过理论分析和实验研究,分析了润湿反转的本质并实现了多孔介质表面由液湿性转变为优先气湿;然后提出了可表征固体表面气体润湿能力大小的参数ζ,应用停滴法建立了采用气湿参数ζ进行气湿性定量评价的方法,确立了气湿性定量评价指标,并采用毛细管上升实验,进一步验证了停滴法实验结果的正确性.实验结果表明:通过降低固体表面和固—液界面自由能是实现优先气湿的有效方法,随着Zony18740含量的增加,固体表面自由能降低,其表面的憎液亲气性增强.     

新型耐温耐盐气润湿岩心的制备及性能评价

为了解非离子型气湿反转剂在改变砂岩表面润湿性方面的作用效果,获得气润湿性良好的砂岩地层,提高凝析气藏的生产能力,分别采用接触角法和Owens二液法考察了非离子型表面活性剂处理前后砂岩岩心的气润湿程度和表面自由能,研究了无机盐、温度和pH值对气润湿性的影响及气润湿反转的有效期。结果表明,质量 分数为0.3%的非离子型氟碳表面活性剂（FG24）可将岩心表面的润湿性由液润湿性反转为强气润湿性,水相和油相在岩心表面的接触角由处理前的36.0°和0°分别增至141.3°和108.0°,且岩心的表面自由能由71.0 mN/m急剧降至3.29 mN/m。在pH值为1～10、无机盐溶液质量浓度为100 g/L、温度140℃范围内,油水相在岩心表面的接触角均大于90°;岩心可在60 d 内保持强气润湿性。FG24 可将岩心表面反转为強气湿性,并具有良好的耐盐性和耐温性。图4 表1 参14     

基于遗传运算法QSPR模型预测润滑剂在铜箔表面的润湿能力

采用静态悬滴法研究了润滑剂中脂肪酸、醇类和酯类添加剂在压延铜箔表面的接触角和润湿行为。利用半经验的量子化学方法计算了这些化合物的一些结构参数对其接触角进行了研究。利用遗传运算(GFA)统计分析方法，通过分子折射率和几种结构参数研究了其定量结构-性质关系。结果表明计算的量子参数可用于预测润滑剂在压延铜箔表面的接触角和润湿能力。这些润滑剂的接触角是其粘度、界面张力和物理化学参数的函数。其中起到主要作用的参数中，分子的折射率、分子的折射率、分子的弹性、总分子质量、溶剂表面积、元素计数、总能量和偶极子最关键。值得注意的是，润滑剂在压延铜箔表面的研究使润湿理论能精确到微观尺度，这为预测润滑剂在压延铜箔表面的润湿能力提供了新的见解。     

鼠李糖脂液-固界面润湿改性机制

生物表面活性剂为一种特定微生物代谢产生的具有表面活性的物质,通过在岩石表面的吸附来达到改变 其润湿性的目的,而润湿改性机制对油藏提高采收率至关重要。通过接触角的测定、洗油砂评价、液-固界面自 由能计算及分子动力学模拟等方法,研究了鼠李糖脂表面活性剂与疏水SiO₂ 表面间的相互作用,并对其吸附特 性和润湿改性机制进行了阐释。结果表明,鼠李糖脂可快速改善亲油玻片表面的润湿性。经10%鼠李糖脂溶液 浸泡12h后,亲油玻片的接触角从111.6°降至32.7°。鼠李糖脂溶液对油砂的最佳洗油有效加量为30%,洗油效 率可达84.83%,原油黏附功降低了98.4%。通过液-固界面自由能计算得到去离子水与鼠李糖脂溶液作用后的亲 油玻片间的自由能为-140.2mJ/m²,远低于去离子水与原始亲油玻片间的自由能（-52.1mJ/m²）。分子模拟计算 结果表明,鼠李糖脂分子主要通过氢键这一强作用力吸附在亲水SiO₂ 表面,其与亲水界面的吸附结合能达到 29.7 eV;而鼠李糖脂分子与疏水SiO₂ 表面的作用力为静电力和范德华力等弱作用力,导致其与疏水界面的吸附 结合能仅为12.2eV。结合液-固界面自由能和分子模拟计算结果推测,鼠李糖脂分子相较于原油极性分子具有 更强的界面竞争吸附能力,从而使其易于锚定到亲水表面、最终替换油性分子,达到提高洗油效率的目的。研究 结果可为构建以鼠李糖脂为主的生物润湿调控驱油体系提供理论支撑。     

界面扩张流变法研究有机碱与原油活性组分的界面相互作用

从胜利油田渤61原油中分离得到胶质和沥青质,通过滴外形分析方法研究了两种原油组分模拟油（质量分数0.5%,由航空煤油配制）与乙醇胺溶液间的界面张力及界面扩张流变性质。结果表明,乙醇胺与胶质中脂肪酸反应,形成脂肪酸和皂的混合吸附膜,有利于界面张力的降低,但对界面扩张模量影响不大。乙醇胺与沥青质中芳香酸的反应能促进芳香酸的吸附,降低界面张力,同时增加膜强度;但随着乙醇胺浓度的进一步增大,芳香酸皂扩散交换作用对界面膜的影响增强,界面膜黏性部分增加,膜强度有所降低。     

The Application of Grey System Theory to Correlate Chemical Composition and Surface Free Energy of Asphalt Binders

Abstract

Grey correlation analyses were carried out to determine which chemical components and chemical elements of asphalt binders are most related to surface free energy (SFE) measurements of asphalt binders. The total, dispersive, and polar SFE values were calculated for 23 Strategic Highway Research Program (SHRP) asphalt binders based on contact angle measurements by the sessile drop method and the chemical composition data of the 23 binders was obtained from previously published information. During the Grey correlation analysis, it was found that polar aromatics content has the largest effect on the total SFE and dispersion component of SFE, whereas saturates made the largest contribution to the polar component of SFE. Carbon (C) and hydrogen (H) made the largest contribution to the total, dispersion, and polar SFE; vanadium (V) content has the smallest effect on the total surface free energy, including its dispersion and polar parts.     

Investigation of the asphalt–aggregate interaction using molecular dynamics

The objective of this study is to explore the self-healing process or diffusion of the asphalt materials on aggregates through the experiments and molecular dynamics (MD) simulations. The asphalt mastic samples were prepared with binders and fine aggregates. The microscale dynamic X-ray computed tomography was conducted to capture the self-diffusion process of the binder in the asphalt mastic controlled at 353.15 K using Advanced Photon Source beamline 2-BM. The Mean Square Displacements were analyzed to describe the self-healing behaviors of binders by an MD method. The results of tests and MD simulations show that the molecules of the asphalt model on the nanoscale at high temperatures move faster those at low temperatures. The asphalt molecules move forward to aggregate layer and expand contact area to reduce the system energy.     

The addition effects of macro and nano clay on the performance of asphalt binder

The study was carried out to explore the addition effect of macro and organically modified nanoclay on the physical and mechanical properties of asphalt binders. Both macroclay and modified nanoclay were blended in an asphalt binder in various percentages (starting from 2% to 8%). The blended asphalt binders were characterized using kinematic viscosity (C.st), softening point (°C), and penetration and compared with anunmodified binder. The tensile strength of the asphalt binders was also tested as a function of clay types and content%. The results of the study indicated an increase in softening point; kinematics viscosity and decrease in binder penetration. The tensile strength of modified clay binders was enhanced at all percentages by a comparison with both macroclay and unmodified binders. The best improvements in the modified binders were obtained with 6% nanoclay.     

Rheological and aging properties of warm mix asphalt binders containing expanded vermiculite

The scope of this study was to investigate the high and intermediate temperature rheological and aging properties of warm mix asphalt binders modified by organo-expanded vermiculites. The rotational viscosity, complex modulus, and rutting parameter (G^*/δ) increased and the penetration and phase angle decreased after modification of 3% organo-expanded vermiculites, indicating that the high temperature rheological properties of the warm mix asphalt binder have been improved. The warm mix asphalt binders containing 3% organo-expanded vermiculites demonstrate the lowest value of phase angle and the highest value of complex modulus compared with the studied binders. In addition, as a result of the rolling thin film oven test, the viscosity aging index of warm mix asphalt binder decreases, while the retained penetration increases obviously with the introduction of organo-expanded vermiculites. The warm mix asphalt binder with 3% organo-expanded vermiculites has more pronounced improvements in aging resistance in comparison with other studied modified warm mix asphalt binders.     

A Laboratory Investigation on the Rheological Properties of Aged and Unaged Organic Wax Modified Asphalt Binders

Different proportions of Sasobit (Sasol Wax, Hamburg, Germany) content were blended with 60–70 penetration grade asphalt binder type and were subjected to physical and rheological tests in order to determine the influence of Sasobit on asphalt binder. The test results indicated that Sasobit had different effects on temperature susceptibility of binders. Frequency sweep test showed that binders containing Sasobit had higher complex modulus compared to the control binders. In addition, lower phase angle values were observed for Sasobit-modified binders. FTIR analysis showed changes in the microstructure and weight distribution of Sasobit-modified binders.     

Evaluation of rutting resistance of asphalt binders and asphalt mixtures modified with polyphosphoric acid

In this research, a polyphosphoric acid (PPA) additive was used to modify a performance graded binder (PG 58-22). Experimental program included use of three PPA contents (0.5%, 1%, and 1.5%) by weight of bitumen and use of antistripping limestone aggregates. High-temperature rheological properties of asphalt binders were evaluated through the frequency sweep test. Complex modulus test was also used to evaluate rutting characteristics of asphalt mixtures. Results showed that PPA significantly improved rutting resistance of both unmodified asphalt binder and unmodified asphalt mixture, especially for the asphalt binder.     

Properties of asphalt binder and asphalt concrete containing waste polyethylene

In this study, the effects of addition of waste polyethylene on asphalt binder and asphalt concrete mixture properties were studied. Four asphalt concrete mixtures (each mixture containing different percentages of shredded polyethylene material) were prepared and tested as per Indian specifications. Shredded polyethylene and hot asphalt binder were added to heated aggregate (in same sequence) until all aggregates were coated. The loose mixtures were compacted and tested for its mechanical and volumetric properties. Furthermore, compacted specimens were aged for short- and long-term conditions. The extracted binder from the aged and control mixtures was tested for its rheological properties using a dynamic shear rheometer. Mixtures containing shredded polyethylene showed improvement with respect to the Marshall strength, flow, and volumetric properties. The properties of recovered asphalt binder indicated that the addition of polyethylene improved complex modulus values and decreased phase angle values over range of frequencies.     

沥青软化点温度下的粘弹特征

本文对30余个沥青样品进行了动态剪切扫描试验,探讨了软化点环境下的沥青的粘弹性状态。试验发现：在软化点温度条件下,纯沥青与改性沥青处于两种不同的流变状态,石油沥青粘弹组成中粘性分量居多,相位角多在80o以上;而SBS改性沥青则保持较低的模量值和相位角,弹性仍保持为一个明显的特质。同时,利用Shapiro-Wilk正态检验发现,在a=0.05置信水平下,不管老化状态如何,纯沥青软化点对应一个稳定的复数模量,在荷载100Pa、频率10rad/s的实验条件下,该模量均值为13033.7Pa,标准差为2104.7Pa。并利用这种等模量规律求取纯沥青的软化点,证明了与实测软化点的良好关联性。需要更多数据以验证本文的初步结论。     

Thermal and rheological properties of nanoparticle modified asphalt binder at low and intermediate temperature range

There is a paucity of knowledge regarding the effect of nanoparticles on the performance of asphalt binder against fatigue and low-temperature cracking. In this research, asphalt binders were modified using SiO₂, TiO₂, and CaCO₃ nanoparticles, and rheological and thermal properties of the modified binders were investigated. Differential scanning calorimetry was used to determine glass transition temperature, and rheological properties at low and intermediate temperatures were determined using bending beam and dynamic shear rheometers, respectively. The results suggested that the addition of these nanoparticles increases glass transition temperature and the low-temperature stiffness of asphalt binder. Furthermore, increase in complex shear modulus and decrease in phase angle values were observed at intermediate temperatures. It can be concluded that inferior performance at low and intermediate temperature is expected by the addition of nanoparticles to asphalt binder.