乳化液膜污染现象与DLVO理论预测矛盾性解析

doi:10.16085/j.issn.1000-6613.2024-1328

摘要/Abstract

摘要：

采用不同类型乳化剂稳定的含油污水对聚醚砜（PES）超滤膜进行污染机理研究，揭示了膜污染现象与Derjaguin-Landau-Verwey-Overbeek（DLVO）理论预测矛盾性的分子行为诱导机制。结果表明，乳化剂的电性及电位对油滴稳定性有较大影响。在相同过滤时间内，十六烷基三甲基溴化铵（CTAB）乳化液通量最高，十二烷基磺酸钠（SDS）乳化液通量最低，说明CTAB-乳化液产生的膜污染较轻，SDS-乳化液产生的膜污染较严重。DLVO理论预测结论与实验现象相反，CTAB-乳化液中油滴最易接近膜表面产生污染，而SDS-乳化液中的油滴需要克服较大的能垒才可产生膜污染。分子模拟结果说明CTAB与膜的吸附能最大，其次为吐温80（Tween 80），SDS最小，且乳化剂分子的吸附能均高于油分子。此外，CTAB和SDS的静电能在总吸附能中均占比较大，而Tween 80与膜的吸附则以范德华力为主导，离子型乳化剂因其带电特性与膜表面有着较强的静电作用。因此，乳化剂在包裹油分子靠近膜表面时，乳化剂分子较油分子优先吸附到膜表面及膜孔中，从而形成隔绝层，且吸附能越大的乳化剂作用越明显。油滴因乳化剂缺失产生的破乳效应及乳化剂吸附到膜孔中形成的位阻效应进一步隔绝油的附着，从而减轻膜污染。

关键词: 乳化剂, 膜污染, DLVO, 分子模拟, 吸附能

Abstract:

The contradiction between membrane fouling propensity and Derjaguin-Landau-Verwey-Overbeek (DLVO) theory by various emulsifiers were systematically investigated at the molecular level. It was indicated the electrical property and potential of emulsifiers had a significant impact on the stability of oil droplets. Under the same filtration time, the flux of cetyltrimethylammonium bromide (CTAB)-stabilized emulsion was higher than that of sodium dodecyl sulfate (SDS), showing the less membrane fouling by CTAB. Besides, DLVO theory illustrated the opposite phenomenon that CTAB stabilized emulsion was easier to adsorb to membrane surface and caused fouling while SDS-emulsion needed to overcome a large energy barrier to cause fouling. Additionally, molecular simulation expounded the fouling mechanism resulted from the different adsorption energy between oil/emulsifier molecules and membrane. The larger interaction between polyether sulfone (PES) and CTAB contributed to the rapid adsorption, followed by that with Tween 80 and then SDS. It was also found that electrostatic energy of CTAB and SDS played an important role in total interaction effect while Van Der Waals force dominated the adsorption of PES-Tween. Therefore, emulsifiers especially for CTAB preferentially adsorbed on membrane surface and inner channels to cause demulsification and steric hindrance, which formed an isolation layer to resist oil and alleviate membrane fouling.

Key words: emulsifier, membrane fouling, Derjaguin-Landan-Verwey-Overbeek, molecular simulation, adsorption energy

中图分类号:

X703

杨严, 李丹松. 乳化液膜污染现象与DLVO理论预测矛盾性解析[J]. 化工进展, 2025, 44(10): 6023-6031.

YANG Yan, LI Dansong. Contradiction between membrane fouling phenomenon and DLVO theory prediction in different oil-in-water emulsions[J]. Chemical Industry and Engineering Progress, 2025, 44(10): 6023-6031.

图/表 8

表1 不同溶液的表面张力系数

溶液	γ^LW/mN·m^-1	γ⁺/mN·m^-1	γ^-/mN·m^-1	γ^TOT/mN·m^-1
水	21.8	25.5	25.5	72.8
甘油	34	3.9	57.4	64
二碘甲烷	50.8	0	0	50.8

图1 不同类型乳化液透射光和参比谱图

图2 不同乳化液的稳定性和外观

图3 不同类型乳化液通量衰减、通量及截留率

图4 原始膜和污染膜的SEM

图5 不同乳化液与膜之间的相互作用

表2 不同乳化液的表面张力系数、相互作用及zeta电位

乳化液	γ^LW/mN·m^-1	γ⁺/mN·m^-1	γ^-/mN·m^-1	$G h 0 L W$ /mJ·m^-2	zeta电位/mV
CTAB	46.25	0.31	35.05	-9.77	65.38
Tween 80	44.74	1.86	27.35	-9.25	-27.44
SDS	42.07	1.81	10.50	-8.32	-57.38

表2 不同乳化液的表面张力系数、相互作用及zeta电位

乳化液	γ^LW/mN·m^-1	γ⁺/mN·m^-1	γ^-/mN·m^-1	$G h 0 L W$ /mJ·m^-2	zeta电位/mV
CTAB	46.25	0.31	35.05	-9.77	65.38
Tween 80	44.74	1.86	27.35	-9.25	-27.44
SDS	42.07	1.81	10.50	-8.32	-57.38

图6 不同乳化剂/油分子与PES膜的吸附模型、相互作用及乳化剂分子的静电势分布

参考文献 23

[24]	王可, 樊华, 侯得印, 等. XDLVO理论解析有机物在膜蒸馏过程中的膜污染行为机制[J]. 膜科学与技术, 2022 42(2): 25-33.
	WANG Ke, FAN Hua, HOU Deyin, et al. Mechanism of membrane fouling in membrane distillation process by organic compounds: XDLVO theory[J]. Membrane Science and Technology, 2022 42(2): 25-33.
[25]	BRENELLI Lívia Beatriz, MARIUTTI Lilian Regina Barros, VILLARES PORTUGAL Rodrigo, et al. Modified lignin from sugarcane bagasse as an emulsifier in oil-in-water nanoemulsions[J]. Industrial Crops and Products, 2021, 167: 113532.
[26]	MATOS María, Gemma GUTIÉRREZ, LOBO Alberto, et al. Surfactant effect on the ultrafiltration of oil-in-water emulsions using ceramic membranes[J]. Journal of Membrane Science, 2016, 520: 749-759.
[27]	PARIA Santanu, KHILAR Kartic C. A review on experimental studies of surfactant adsorption at the hydrophilic solid-water interface[J]. Advances in Colloid and Interface Science, 2004, 110(3): 75-95.
[1]	ZHANG Ning, YANG Xianwen, WANG Yalun, et al. A review on oil/water emulsion separation membrane material[J]. Journal of Environmental Chemical Engineering, 2022, 10(2): 107257.
[2]	SUTRISNA Putu Doddy, KURNIA Kiki Adi, SIAGIAN Utjok W R, et al. Membrane fouling and fouling mitigation in oil-water separation: A review[J]. Journal of Environmental Chemical Engineering, 2022, 10(3): 107532.
[3]	HUANG Shilin, RAS Robin H A, TIAN Xuelin. Antifouling membranes for oily wastewater treatment: Interplay between wetting and membrane fouling[J]. Current Opinion in Colloid & Interface Science, 2018, 36: 90-109.
[4]	GAO Shoujian, CHEN Jinhao, ZHENG Yanru, et al. Gradient adhesive hydrogel decorated superhydrophilic membranes for ultra-stable oil/water separation[J]. Advanced Functional Materials, 2022, 32(46): 2205990.
[5]	XIE Xiong, BAO Jianguo, HASSAN OMER Safaa, et al. Study for adsorption behaviors of emulsion oil on a novel ZrO₂/PVDF modified membrane[J]. Desalination and Water Treatment, 2016, 57(25): 11736-11745.
[6]	ZHANG Bing, YU Shuili, ZHU Youbing, et al. Adsorption mechanisms of crude oil onto polytetrafluoroethylene membrane: Kinetics and isotherm, and strategies for adsorption fouling control[J]. Separation and Purification Technology, 2020, 235: 116212.
[7]	ZHAO Dongsheng, LIU Junxia, QIU Liping, et al. Roles of a mixed hydrophilic/hydrophobic interface in the regulation of nanofiltration membrane fouling in oily produced wastewater treatment: Performance and interfacial thermodynamic mechanisms[J]. Separation and Purification Technology, 2021, 257: 117970.
[8]	吕东伟. 陶瓷超滤膜分离乳化油过程中膜污染机制与抗污染改性研究[D]. 哈尔滨：哈尔滨工业大学, 2016.
	Dongwei LYU. Study on membrane fouling mechanism and anti-pollution modification in the process of separating emulsified oil by ceramic ultrafiltration membrane[D]. Harbin: Harbin Institute of Technology, 2016.
[9]	TANUDJAJA Henry J, CHEW Jia W. Assessment of oil fouling by oil-membrane interaction energy analysis[M]//Solid-liquid separation technologies. Boca Raton: CRC Press, 2022: 151-168.
[10]	HE Zhengwang, KASEMSET Sirirat, KIRSCHNER Alon Y, et al. The effects of salt concentration and foulant surface charge on hydrocarbon fouling of a poly(vinylidene fluoride) microfiltration membrane[J]. Water Research, 2017, 117: 230-241.
[11]	TIAN Ju, TRINH Thien An, KALYAN Muppalla Naga, et al. In-situ monitoring of oil emulsion fouling in ultrafiltration via electrical impedance spectroscopy (EIS): Influence of surfactant[J]. Journal of Membrane Science, 2020, 616: 118527.
[12]	TRINH Thien An, HAN Qi, MA Yunqiao, et al. Microfiltration of oil emulsions stabilized by different surfactants[J]. Journal of Membrane Science, 2019, 579: 199-209.
[13]	ZHANG Tong, WANG Qiaoying, YANG Yan, et al. Revealing the contradiction between DLVO/XDLVO theory and membrane fouling propensity for oil-in-water emulsion separation[J]. Journal of Hazardous Materials, 2024, 466: 133594.
[14]	LAY Huang Teik, Chi Siang ONG, WANG Rong, et al. Choice of DLVO approximation method for quantifying the affinity between latex particles and membranes[J]. Journal of Membrane Science, 2023, 666: 121121.
[15]	ESKHAN Asma, ALQASAS Neveen, JOHNSON Daniel. Interaction mechanisms and predictions of the biofouling of polymer films: A combined atomic force microscopy and quartz crystal microbalance with dissipation monitoring study[J]. Langmuir, 2023, 39(18): 6592-6612.
[16]	LIU Junxia, FAN Yaqian, SUN Yuhui, et al. Modelling the critical roles of zeta potential and contact angle on colloidal fouling with a coupled XDLVO-collision attachment approach[J]. Journal of Membrane Science, 2021, 623: 119048.
[17]	ZHANG Bing, TANG Heli, HUANG Dongmei, et al. Effect of pH on anionic polyacrylamide adhesion: New insights into membrane fouling based on XDLVO analysis[J]. Journal of Molecular Liquids, 2020, 320: 114463.
[18]	陆登荣, 刘红波, 钱大玮, 等. XDLVO理论解析中药共性高分子的超滤膜污染行为[J]. 中草药, 2022, 53(9): 2642-2649.
	LU Dengrong, LIU Hongbo, QIAN Dawei, et al. Analysis of ultrafiltration membrane fouling behavior of common polymers in traditional Chinese medicine using XDLVO theory[J]. Chinese Traditional and Herbal Drugs, 2022, 53(9): 2642-2649.
[19]	ZHAO Fangchao, LI Zongxue, HAN Xixi, et al. The interaction between microalgae and membrane surface in filtration by uniform shearing vibration membrane[J]. Algal Research, 2020, 50: 102012.
[20]	BRANT Jonathan A, CHILDRESS Amy E. Assessing short-range membrane-colloid interactions using surface energetics[J]. Journal of Membrane Science, 2002, 203(1/2): 257-273.
[21]	李义雅, 龙军, 段庆华, 等. 分子动力学模拟研究矿物基础油润滑性能[J]. 石油学报(石油加工), 2017, 33(4): 619-625.
	LI Yiya, LONG Jun, DUAN Qinghua, et al. Molecular dynamics simulation on the lubricating property of mineral base oil[J]. Acta Petrolei Sinica (Petroleum Processing Section), 2017, 33(4): 619-625.
[22]	WANG Jianmei, DUAN Lintao, WANG Baoan. Interface microstructure and bonding energy of layered bimetallic ZCuSn₆Pb₆Zn₃/steel coupling with temperature and pressure[J]. Tribology International, 2021, 155: 106754.
[23]	WANG Jianmei, XIA Quanzhi, MA Yang, et al. Interfacial bonding energy on the interface between ZChSnSb/Sn alloy layer and steel body at microscale[J]. Materials, 2017, 10(10): 1128.