Bioinspired Hybrid Nanostructures for Wax Inhibition Coatings with Superhydrophilicity

Abstract

Wax deposition is a severe flow assurance problem in the petroleum industry. Superhydrophilic coatings have huge potential in wax inhibition based on the water film theory, but their practical applications are severely limited by their fragile structure and unstable water film. Herein, inspired by the remarkable water management abilities of desert lizards, we fabricated a novel TiO2/diatomite/aluminum dihydrogen phosphate (TiO2/DIA/ADP) superhydrophilic coating with hybrid nanostructures that combined hierarchical protrusion and micro-/nanochannel systems. This bioinspired nanostructure induces a potent capillary effect on water, which, along with hydrogen bonds in hydrophilic composition and coordination bonds contributed by the Ti ion in the tetrahedral environment, established a robust water film on the surface of the coating. The water film imparted underwater superoleophobicity and nearly 100% wax inhibition efficiency. In addition, the interfacial strength of the TiO2/DIA/ADP coating is enhanced by the Ti–O–Si covalent bond and the three-dimensional (3D) cross-linked phosphate network formed through ADP. Consequently, the coating retained excellent underwater oil repellency and wax inhibition efficiency even after being treated with 3.5 wt % NaCl solution and strong acidic as well as mechanical wear resistance in air/water. Thus, this research not only contributes to a comprehensive understanding of the antiwax mechanism based on the water film theory but also provides new insights into antiwax coating with an ultrahigh wax inhibition efficiency in the petroleum industry and durable superhydrophilic coating for applications under harsh conditions.

Insights into the Response Differences of Ultrasonic Rolled A3 Carbon Steels and 316L Stainless Steels to Scale and Wax Precipitation Behavior

“…In the process of petroleum exploitation and transportation, the wax dissolved in the hot crude oil may experience crystallization, precipitation and subsequently deposition on the inner wall of the pipelines as the temperature and pressure change. [4,13] In response to this problem, some antiwaxing methods, such as mechanical dewaxing, paraffin inhibitors, thermal dewaxing, the microbial method, equipment technology (including magnetic field dewaxing), and surface film layers, have been widely developed. [13,[46][47][48][49] Currently, it can be considered that a smooth and low energy surface is more likely to inhibit the wax adhering on the pipeline surface and the precipitated wax molecules are also not easy to adsorb and deposit and thus the antiwaxing purpose can be achieved.…”

“…[4,13] In response to this problem, some antiwaxing methods, such as mechanical dewaxing, paraffin inhibitors, thermal dewaxing, the microbial method, equipment technology (including magnetic field dewaxing), and surface film layers, have been widely developed. [13,[46][47][48][49] Currently, it can be considered that a smooth and low energy surface is more likely to inhibit the wax adhering on the pipeline surface and the precipitated wax molecules are also not easy to adsorb and deposit and thus the antiwaxing purpose can be achieved. [50] In this case, a dedicated coating not only endows the pipeline with good antiwaxing function but also possesses a certain corrosion resistance, which can protect the pipeline with a "two birds with one stone" effect.…”

“…[11] For this reason, various surface modification strategies have been developed for scale and wax prevention, such as organic coating and plating methods. [12,13] Unfortunately, organic and plating coatings tend to have some obvious drawbacks, such as weak adhesive forces, poor corrosion resistance, and coating performance that does not meet the required standards. [14] To alleviate this situation, extensive methods have also been developed to overcome these shortcomings.…”

Substrate-Independent Cupric Phosphate Nanoflower–Mineralized Superhydrophilic Membranes for Diverse Oil–Water Separation

“…Membrane separation technology has garnered considerable attention for the treatment of diverse oily wastewater because of its low power consumption and high efficiency. – However, membrane fouling is a considerable disadvantage of traditional membranes because it sharply decreases the membrane flux due to oil adhesion-induced pore clogging. Generally, fouling can be alleviated by increasing the hydrophilicity of the membrane because hydrophilicity is mainly associated with the surface properties of the membrane. – Currently, the development of superhydrophilic/underwater superoleophobic membrane materials with self-cleaning behavior has become a hot research area in diverse oily wastewater purification.…”

Preparation of Degradable Antiwaxing Coating and a Novel Method for Quantifying Antiwaxing Property of Coatings

“…To address the problem of wax deposition, some different methods have been developed, such as mechanical cleaning, chemical additives, and the formation of micronano structures. − However, these methods are time-consuming or energy-consuming. It is an emergency requirement to develop a low-cost and effective method to inhibit the deposition of wax.…”