Liang Jiling, Han Tingting, Wang Wenwu, Zhang Lunqiu, Zhang Yan
School of Civil Engineering, Liaoning Petrochemical University, Fushun 113001, China.
Materials (Basel). 2023 Jul 31;16(15):5367. doi: 10.3390/ma16155367.
To design more environmentally friendly, economical, and efficient demulsifiers for oily wastewater treatment, hydrophobic octadecylphosphonic acid (ODPA)-modified FeO nanoparticles (referred to as FeO@ODPA) were prepared by condensation of hydroxyl groups between ODPA and FeO nanoparticles using the co-precipitation method. The prepared magnetite nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric/differential thermogravimetric (TG/DTG) analysis. The water contact angles () of FeO@ODPA nanoparticles were more than 120°, indicating hydrophobic nature, and the diameter of the obtained spherical-shaped magnetite nanoparticles was 12-15 nm. The ODPA coating amount () (coating weight per gram FeO) and specific surface area () of FeO@ODPA were 0.124-0.144 g·g and 78.65-91.01 m·g, respectively. To evaluate the demulsification ability, stability, and reusability, the magnetite nanoparticles were used to demulsify an n-hexane-in-water nanoemulsion. The effects of the magnetite nanoparticle dosage (), pH value of nanoemulsion, and NaCl or CaCl electrolytes on the demulsification efficiency () were investigated. The of FeO@ODPA samples was found to be higher than that of bare FeO samples (S0, ST, and SN) under all values. With the increase in , the of FeO@ODPA samples initially increased and then approached equilibrium value at Cs = 80.0 g·L. A maximum of ~93% was achieved at = 100.0 g·L for the FeO@ODPA sample S2. The pH and two electrolytes had a minor effect on The FeO@ODPA nanoparticles maintained high even after being reused for demulsification 11 times. This indicates that the hydrophobic FeO@ODPA samples can be used as an effective magnetite demulsifer for oil-in-water nanoemulsions.
为设计出更环保、经济且高效的用于含油废水处理的破乳剂，采用共沉淀法，通过十八烷基膦酸（ODPA）与FeO纳米颗粒之间的羟基缩合制备了疏水的十八烷基膦酸改性FeO纳米颗粒（简称FeO@ODPA）。通过X射线衍射（XRD）、透射电子显微镜（TEM）、扫描电子显微镜（SEM）、傅里叶变换红外（FTIR）光谱以及热重/微商热重（TG/DTG）分析对制备的磁铁矿纳米颗粒进行了表征。FeO@ODPA纳米颗粒的水接触角大于120°，表明具有疏水性，所获得的球形磁铁矿纳米颗粒直径为12 - 15 nm。FeO@ODPA的ODPA包覆量（每克FeO的包覆重量）和比表面积分别为0.124 - 0.144 g·g和78.65 - 91.01 m·g。为评估破乳能力、稳定性和可重复使用性，使用磁铁矿纳米颗粒对水包正己烷纳米乳液进行破乳。研究了磁铁矿纳米颗粒用量、纳米乳液的pH值以及NaCl或CaCl电解质对破乳效率的影响。发现在所有Cs值下，FeO@ODPA样品的破乳效率均高于裸FeO样品（S0、ST和SN）。随着Cs的增加，FeO@ODPA样品的破乳效率最初增加，然后在Cs = 80.0 g·L时接近平衡值。对于FeO@ODPA样品S2，在Cs = 100.0 g·L时破乳效率最高达到约93%。pH值和两种电解质对破乳效率影响较小。FeO@ODPA纳米颗粒即使在重复用于破乳11次后仍保持较高的破乳效率。这表明疏水性的FeO@ODPA样品可作为水包油纳米乳液的有效磁铁矿破乳剂。
