Molecular dynamics simulation and experimental study on the influence of hydrophilic group on the adsorption of dodecyl anionic emulsifier on SiO2 surface
-
摘要: 乳化沥青破乳过程中,乳化剂分子亲水基团吸附于集料表面,亲油基团牵引沥青微滴向集料表面聚集,从而达到破乳。因此,为了探究乳化剂亲水基团对乳化沥青破乳过程的影响,通过分子动力学模拟和电导率试验探究了疏水基团为十二烷基碳链、亲水基团不同的5种阴离子乳化剂在玄武岩主要化学成分(SiO2)表面的吸附情况。模拟结果表明,亲水基团中的K+比Na+更能增强十二烷基阴离子乳化剂与水分子间的范德华相互作用,促进十二烷基阴离子乳化剂在SiO2表面的聚集和吸附;在亲水基团中引入苯基官能团可提高十二烷基阴离子乳化剂与水分子间的范德华相互作用、十二烷基阴离子乳化剂在SiO2表面的吸附能力,苯基官能团的引入率越高,十二烷基阴离子乳化剂与水分子间的范德华相互作用及十二烷基阴离子乳化剂在SiO2表面的吸附能力越强;由于库仑力的作用,5种十二烷基阴离子乳化剂的疏水基团尾端C原子、亲水基团极性头S原子在SiO2表面的扩散行为比十二烷基阴离子乳化剂自身在SiO2表面的扩散行为弱。试验结果表明5种十二烷基阴离子乳化剂在SiO2表面的吸附量随着乳化剂浓度和固/液比的增大而增加;5种阴离子乳化剂在SiO2表面的吸附量大小排序与分子动力学模拟的结果一致,验证了结论的可靠性。
-
关键词:
- 十二烷基阴离子乳化剂 /
- 亲水基团 /
- SiO2 /
- 吸附 /
- 分子动力学模拟
Abstract: In the process of emulsified asphalt demulsification, the hydrophilic group of the emulsifier molecule is adsorbed on the surface of the aggregate, and the lipophilic group pulls the asphalt droplets to aggregate on the surface of the aggregate to achieve complete demulsification. Therefore, in order to explore the influence of hydrophilic groups of emulsifier on demulsification process of emulsified asphalt, the adsorption of five kinds of anionic emulsifiers with different hydrophobic groups of dodecyl carbon chain and hydrophilic groups on the surface of the main chemical component (SiO2) of basalt was explored by molecular dynamics and electrical conductivity experiments. The simulation results show that the K+ in the hydrophilic group can enhance the van der Waals interaction between the dodecyl anionic emulsifier and water molecules more than Na+, and promote the aggregation and adsorption of the dodecyl anionic emulsifier on the SiO2 surface. The introduction of phenyl functional group into the hydrophilic group can improve the van der Waals interaction between dodecyl anion emulsifier and water molecules and the adsorption capacity of dodecyl anion emulsifier on the surface of SiO2. The higher the introduction rate of phenyl functional groups, the stronger the van der Waals interaction between the dodecyl anionic emulsifier and water molecules and the stronger the adsorption capacity of the dodecyl anionic emulsifier on the SiO2 surface. Because of the action of Coulomb force, the diffusion behavior of C atom at the tail end of hydrophobic group and S atom at the polar head of hydrophilic group on the surface of SiO2 is weaker than that of the five dodecyl anionic emulsifiers. The experimental results show that the adsorption capacity of five kinds of dodecyl anionic emulsifiers on SiO2 surface increases with the increase of emulsifier concentration and solid/liquid ratio. The order of the adsorption amount of the five anionic emulsifiers on the SiO2 surface is consistent with the results in molecular dynamics, which verifies the reliability of the conclusion.-
Key words:
- dodecyl anionic emulsifier /
- hydrophilic group /
- SiO2 /
- adsorption /
- molecular dynamics simulation
-
表 1 十二烷基阴离子乳化剂溶液盒子尺寸
Table 1. Dodecyl anionic emulsifier solution box size
Emulsifier solution Nwater Nemulsifier Cubic size/nm SDBS solution 1543 20 2.99×2.99×6.44 SDSN solution 1210 20 2.99×2.99×5.05 SDS solution 1280 20 2.99×2.99×5.34 PDS solution 1351 20 2.99×2.99×5.64 SLDED solution 2403 20 2.99×2.99×10.03 Notes: Nwater—Number of water molecules; Nemulsifier—Number of dodecyl anionic emulsifier molecule. 表 2 乳化剂亲水基团水合层内水分子个数
Table 2. Number of water molecules in the hydration layer of hydrophilic group of emulsifier
Types of anionic emulsifiers PDS SDS SDSN SDBS SLDED S-Ow 47.655 25.896 26.009 25.716 46.720 表 3 电导率试验化学试剂相关参数
Table 3. Relevant parameters of chemical reagents for conductivity test
Name Abbreviation Content/% Morphology Origin Sodium dodecyl benzene sulfonate SDBS 99 Powder solid Hefei BASF Biotechnology CO., LTD. Sodium dodecyl sulfate SDS 90 Powder solid Shandong Yousuo Chemical Technology CO., LTD. Potassium dodecyl sulfate PDS 94 Granular solid Shandong Yousuo Chemical Technology CO., LTD. Sodium laurylsulfonate SDSN 99 Powder solid Hefei BASF Biotechnology CO., LTD. Sodium Lauryl Diphenyl Ether Disulfonate SLDED 45 Liquid Shandong Yousuo Chemical Technology CO., LTD. Silicon dioxide SiO2 99 Powder solid Tianjin Zhiyuan Chemical Reagent CO., LTD. -
[1] PALMER B J, LIU J. Simulations of micelle self-assembly in surfactant solutions[J]. Langmuir,1996,12(3):746-753. doi: 10.1021/la950979f [2] LIU X, LIU S, FAN M, et al. Decrease of hydrophilicity of lignite using CTAB: Effects of adsorption differences of surfactant onto mineral composition and functional groups[J]. Fuel,2017,197:474-481. [3] GUO J, ZHANG L, LIU S, et al. Effects of hydrophilic groups of nonionic surfactants on the wettability of lignite surface: Molecular dynamics simulation and experimental study[J]. Fuel,2018,231:449-457. [4] LIU X, LIU S, CHENG Y, et al. Decrease in hydrophilicity and moisture readsorption of lignite: Effects of surfactant structure[J]. Fuel,2020,273:117812. doi: 10.1016/j.fuel.2020.117812 [5] LYU X, YOU X, HE M, et al. Adsorption and molecular dynamics simulations of nonionic surfactant on the low rank coal surface[J]. Fuel,2018,211:529-534. [6] NGUYEN N N, NGUYEN A V, DANG L X. The inhibition of methane hydrate formation by water alignment underneath surface adsorption of surfactants[J]. Fuel,2017,197:488-496. [7] ZERDA T W, YUAN X, MOORE S M. Effects of fuel additives on the microstructure of combustion engine deposits[J]. Carbon,2001,39(10):1589-1597. doi: 10.1016/S0008-6223(00)00287-6 [8] BARATI A, NAJAFI A, DARYASAFAR A, et al. Adsorption of a new nonionic surfactant on carbonate minerals in enhanced oil recovery: Experimental and modeling study[J]. Chemical Engineering Research and Design, 2016, 105: 55-63. [9] PEREDO-MANCILLA D, DOMINGUEZ H. Adsorption of phenol molecules by sodium dodecyl sulfate (SDS) surfactants deposited on solid surfaces: A computer simulation study[J]. Journal of Molecular Graphics & Modelling,2016,65:108-112. doi: 10.1016/j.jmgm.2016.02.011 [10] NOURANI M, TICHELKAMP T, GAWEL B, et al. Desorption of crude oil components from silica and aluminosilicate surfaces upon exposure to aqueous low salinity and surfactant solutions[J]. Fuel,2016,180:1-8. [11] AHMADI M A, SHADIZADEH S R. Experimental investigation of adsorption of a new nonionic surfactant on carbonate minerals[J]. Fuel,2013,104:462-467. [12] ZARGARTALEBI M, KHARRAT R, BARATI N. Enhancement of surfactant flooding performance by the use of silica nanoparticles[J]. Fuel,2015,143:21-27. [13] 袁斌, 魏永锋, 祁伟. 沥青乳化剂的微观乳化机理及国内研究进展[J]. 公路交通科技(应用技术版), 2015, 11(7):43-45, 51.YUAN B, WEI Y F, QI W. Micro-emulsification mechanism of asphalt emulsifier and domestic research progress[J]. Journal of Guizhou University of Finance and Economics (Applied Technology Edition),2015,11(7):43-45, 51(in Chinese). [14] 夏朝彬, 马波. 国内外乳化沥青的发展及应用概况[J]. 石油与天然气化工, 2000(2):88-91, 52. doi: 10.3969/j.issn.1007-3426.2000.02.013XIA C B, MA B. Development and application of emulsified asphalt at home and abroad[J]. Chemical Engineering of Oil and Gas,2000(2):88-91, 52(in Chinese). doi: 10.3969/j.issn.1007-3426.2000.02.013 [15] 赵品晖, 范维玉, 田翠芳, 等. CA砂浆用阴离子乳化沥青稳定性研究[J]. 石油炼制与化工, 2012, 43(1):62-67. doi: 10.3969/j.issn.1005-2399.2012.01.014ZHAO P H, FAN W Y, TIAN C F, et al. Study on the stability of anionic emulsified asphalt for CA mortar[J]. Petroleum Refining and Chemical Industry,2012,43(1):62-67(in Chinese). doi: 10.3969/j.issn.1005-2399.2012.01.014 [16] 孔令云, 唐樊龙, 徐燕, 等. 紫外光谱法评价乳化沥青破乳过程[J]. 长安大学学报(自然科学版), 2017, 37(6):17-23.KONG L Y, TANG F L, XU Y, et al. Evaluation of emulsification asphalt demulsification process by UV spectroscopy[J]. Journal of Chang'an University (Natural Science Edition),2017,37(6):17-23(in Chinese). [17] 宋哲玉, 徐培华, 陶家朴. 乳化沥青破乳机理研究[J]. 石油沥青, 1995(3):23-29.SONG Z Y, XU P H, TAO J P. Study on demulsification mechanism of emulsified asphalt[J]. Petroleum Asphalt,1995(3):23-29(in Chinese). [18] 冯虎, 王友刚. 阳离子乳化沥青化学破乳试验研究[J]. 石油沥青, 2012, 26(5):32-34. doi: 10.3969/j.issn.1006-7450.2012.05.007FENG H, WANG Y G. Experimental study on chemical demulsification of cationic emulsified asphalt[J]. Petroleum Asphalt,2012,26(5):32-34(in Chinese). doi: 10.3969/j.issn.1006-7450.2012.05.007 [19] WANG T, JIA H Q, LI H G, et al. Research on water seepage of cement asphalt emulsified (CA) mortar[J]. Construction & Building Materials,2016,125:595-599. [20] ZHANG Y H, WANG F Z. Effect of emulsified asphalt on temperature susceptibility of cement asphalt mortar[J]. Advanced Materials Research,2011,335-336:124-127. doi: 10.4028/www.scientific.net/AMR.335-336.124 [21] ORUC S, CELIK F, AKPINAR M V. Effect of cement on emulsified asphalt mixtures[J]. Journal of Materials Engineering & Performance,2007,16(5):578-583. doi: 10.1007/s11665-007-9095-2 [22] 李云良, 欧阳剑, 王山山, 等. 水泥沥青复合砂浆拌合物乳化沥青破乳过程研究[J]. 哈尔滨工程大学学报, 2015, 36(7):997-1000.LI Y L, OU Y J, WANG S S, et al. Demulsification process of emulsified asphalt with cement asphalt composite mortar mixture[J]. Journal of Harbin Engineering University,2015,36(7):997-1000(in Chinese). [23] 朱晓斌, 洪锦祥, 李炜. 破乳行为对CA浆体流变性能的影响及机理[J]. 建筑材料学报, 2017, 20(4):548-555. doi: 10.3969/j.issn.1007-9629.2017.04.010ZHU X B, HONG J X, LI W. Effect of demulsification behavior of emulsified asphalt on rheological properties in CA Paste and its mechanism[J]. Journal of Building Materials,2017,20(4):548-555(in Chinese). doi: 10.3969/j.issn.1007-9629.2017.04.010 [24] 朱晓斌, 徐静, 刘至飞, 等. CA砂浆的离析与泌水机理探讨[J]. 建筑材料学报, 2014, 17(6):945-951. doi: 10.3969/j.issn.1007-9629.2014.06.002ZHU X B, XU J, LIU Z F, et al. Separation and bleeding mechanism of CA mortar[J]. Journal of Building Materials,2014,17(6):945-951(in Chinese). doi: 10.3969/j.issn.1007-9629.2014.06.002 [25] TANG F, XU G, MA T, et al. Study on the effect of demulsification speed of emulsified asphalt based on surface characteristics of aggregates[J]. Materials,2018,11(9):1488-1503. [26] 孔令云, 李朝波, 唐樊龙, 等. 基于Logistics模型的离心电导率法评价乳化沥青破乳状态[J]. 公路交通技术, 2019, 35(3):26-30.KONG L Y, LI C B, TANG F L, et al. Evaluation of emulsified asphalt emulsion breaking condition by conductivity method based on Logistics model[J]. Technology of Highway and Transport,2019,35(3):26-30(in Chinese). [27] TANG F, ZHU S, XU G, et al. Influence by chemical constitution of aggregates on demulsification speed of emulsified asphalt based on UV-spectral analysis[J]. Construction & Building Materials,2019,212:102-108. [28] ZHOU W, WANG H, YANG Y, et al. Adsorption mechanism of CO2/CH4 in Kaolinite clay: Insight from molecular simulation[J]. Energy & Fuels,2019,33:6542-6551. [29] ZHANG L, GREENFIELD M L. Analyzing properties of model asphalts using molecular simulation[J]. Energy & Fuels,2007,21(3):1712-1716. [30] DAI S L, GUO M, TAN Y Q. Molecular simulation of minerals-asphalt interfacial interaction[J]. Minerals,2018,8(5):176. doi: 10.3390/min8050176 [31] ZENG K, JIANG P, LUN Z, et al. Molecular simulation of carbon dioxide and methane adsorption in shale organic nanopores[J]. Energy & Fuels,2018,33:1785-1796. [32] JUNE R L, BELL A T, THEODOROU D N. Molecular dynamics study of methane and xenon in silicalite[J]. Journal of Physical Chemistry (USA),1990,94(21):8232-8240. doi: 10.1021/j100384a047 [33] 宋其圣, 郭新利, 苑世领, 等. 十二烷基苯磺酸钠在SiO2表面聚集的分子动力学模拟[J]. 物理化学学报, 2009, 25(6):1053-1058. doi: 10.3866/PKU.WHXB20090623SONG Q S, GUO X L, YUAN S L, et al. Molecular dynamics simulation of sodium dodecyl benzene sulfonate aggregation on SiO2 surface[J]. Acta Physico-Chimica Sinica,2009,25(6):1053-1058(in Chinese). doi: 10.3866/PKU.WHXB20090623 [34] 韩颖, 曲广淼, 薛春龙, 等. 十二烷基苯磺酸钠气/液界面聚集行为的分子动力学模拟[J]. 化工科技, 2016, 24(4):22-26. doi: 10.3969/j.issn.1008-0511.2016.04.005HAN Y, QU G M, XUE C L, et al. Molecular dynamics simulation of gas/liquid interface aggregation behavior of sodium dodecyl benzene sulfonate[J]. Science & Technology in Chemical Industry,2016,24(4):22-26(in Chinese). doi: 10.3969/j.issn.1008-0511.2016.04.005 [35] 张雪芳, 潘艳秋, 陈鹏鹏, 等. 乳化剂对动态膜分离油水乳化液过程的影响[J]. 化工进展, 2019, 38(2):790-797.ZHANG X F, PAN Y Q, CHEN P P, et al. Effect of emulsifier on the process of dynamic membrane separation of oil-water emulsion[J]. Chemical Industry and Engineering Progress,2019,38(2):790-797(in Chinese). [36] 范维玉, 赵品晖, 康剑翘, 等. 分子模拟技术在乳化沥青研究中的应用[J]. 中国石油大学学报(自然科学版), 2014, 38(6):179-185.FAN W Y, ZHAO P H, KANG J Q, et al. Application of molecular simulation technology in emulsified asphalt research[J]. Journal of China University of Petroleum (Na-tural Science Edition),2014,38(6):179-185(in Chinese). [37] 孔令云, 李金桥, 张玉贞, 等. 矿粉表面能与其所含化学成分表面能关系模型[J]. 哈尔滨工业大学学报, 2018, 50(9):101-107.KONG L Y, LI J Q, ZHANG Y Z, et al. Model of surface energy relationship between surface energy of mineral powder and its chemical composition[J]. Journal of Harbin Institute of Technology,2018,50(9):101-107(in Chinese). [38] ALLEN M P, TILDESLEY D. Computer simulation of liquids[M]. Oxford: Clarendon Press, 1987. [39] STEPU H. Texture and structural refinement using neutron diffraction data from molybdite (MoO3) and calcite (CaCO3) powders and a Ni-rich Ni50.7 Ti49.30 alloy[J]. Powder Diffraction,2009,24(4):315-326. [40] RAPPÉ A K, CASEWIT C J, COLWELL K S, et al. UFF, a full periodic table force field for molecular mechanics and molecular dynamics simulations[J]. Journal of the American Chemical Society,1992,114:10024-10035. doi: 10.1021/ja00051a040 [41] JUNE R L, BELL A T, THEODOROUDOROS N. Molecular dynamics study of butane and hexane in silicalite[J]. Jour-nal of Physical Chemistry (USA),1992,96:1051-1060. doi: 10.1021/j100182a009 [42] GAO Z Y, SUN W, HU Y H, et al. Surface energies and appearances of commonly exposed surfaces of scheelite crystal[J]. Transactions of Nonferrous Metals Society of China,2013,23(7):2147-2152. doi: 10.1016/S1003-6326(13)62710-7 [43] 王文杰, 卢秀萍. 阴离子水性聚氨酯内乳化剂的研究进展[J]. 聚氨酯工业, 2005(4):6-10. doi: 10.3969/j.issn.1005-1902.2005.04.002WANG W J, LU X P. Research progress of anionic waterborne polyurethane internal emulsifier[J]. Polyurethane Industry,2005(4):6-10(in Chinese). doi: 10.3969/j.issn.1005-1902.2005.04.002 [44] 陈正隆, 徐为人, 汤立达. 分子模拟的理论与实践[M]. 北京: 化学工业出版社, 2007: 110-111.CHEN Z L, XU W R, TANG L D. Theory and practice of molecular simulation[M]. Beijing: Chemical Industry Press, 2007: 110-111(in Chinese). [45] 丁勇杰. 基于分子模拟技术的沥青化学结构特征研究[D]. 重庆: 重庆交通大学, 2013.DING Y J. Study on chemical structure characteristic of asphalt using molecular simulation[D]. Chongqing: Chongqing Jiaotong University, 2013(in Chinese). [46] 李登辉, 李丽洁, 兰贯超, 等. SBS增韧石蜡/增塑剂共混相容性的分子动力学模拟[J]. 含能材料, 2018, 26(3):223-229.LI D H, LI L J, LAN G C, et al. Molecular dynamics simulation on compatibility of SBS toughened paraffin wax/plasticizer blends[J]. Chinese Journal of Energetic Materials,2018,26(3):223-229(in Chinese). [47] 孔令云, 全秀洁, 李朝波, 等. 乳化剂在集料化学成分表面吸附行为的分子模拟与试验论证[J]. 化工进展, 2020, 39(8):3196-3204.KONG L Y, QUAN X J, LI C B, et al. Molecular simulation and experimental demonstration of adsorption behavior of emulsifier on surface of chemical composition of aggregate[J]. Chemical Industry and Engineering Progress,2020,39(8):3196-3204(in Chinese). [48] KONG Lingyun, LUO Wanli, FENG Biao, et al. Influence of emulsifier on surface mass transfer based on molecular dynamics simulations[J]. Frontiers in Materials,2020,7:1-12. [49] 徐龙华, 董发勤, 巫侯琴, 等. 阴离子捕收剂浮选分离—水硬铝石与高岭石的表面晶体化学[J]. 矿物学报, 2016, 36(2):265-270.XU L H, DONG F Q, WU H Q, et al. Surface crystal chemistry in selective flotation of diaspore from kaolinite using anionic collector[J]. Acta Mineralogica Sinica,2016,36(2):265-270(in Chinese). [50] 曹慧平. 集料化学成分/乳化剂传质机理的分子动力学模拟[D]. 重庆: 重庆交通大学, 2016.CAO H P. Molecular dynamics simulation of mass transfer mechanism between chemical composition of aggregate and emulsifier[D]. Chongqing: Chongqing Jiaotong University, 2016(in Chinese).