Effective Crude Oil Pickering Emulsification by Oil-Soluble Spherical Polymer Brushes

Abstract

Crude oil transportation has been increasingly important for chemical industry, and to enhance the flowability of crude oil, various surfactants and amphipathic polymers have been utilized to form oil-in-water emulsions. As an alternative to traditional surfactants, nanoparticulate polymer brushes serve as an ideal scaffold to form Pickering emulsions with crude oil because of their large specific area, excellent stability, and tunable surface property. In our paper, a new type of oil-soluble polymer brushes was utilized to achieve stable crude oil emulsification by forming Pickering emulsions in water. By combining inverse emulsion polymerization and photoemulsion polymerization, poly(N-vinylcarbazole) chains with different lengths were successfully grafted onto the water-soluble poly(acrylic acid) core dispersed in hexane, and the novel series of oil-soluble latex polymer brushes features monodispersity, well-tuned size and fluorescence, and stability, as verified by dynamic light scattering, transmission electron microscopy, UV−vis and fluorescence spectra, as well as small-angle X-ray scattering. More importantly, the amphiphilic nature of the latex particles was successfully utilized to stabilize crude oil droplets in water by forming Pickering emulsions with apparent viscosity reduced by 99%, which is superior to most of the additives used in industry. Therefore, the oil-soluble core−shell latex particles could serve as promising candidates to be applied in petrochemical industry by improving the flowability of heavy crude oil during its exploration, transportation, and recovery process.

Chemical Additives as Flow Improvers for Waxy Crude Oil and Model Oil: A Critical Review Analyzing Structure–Efficacy Relationships

“…They asserted that POA molecules bound to silica surfaces (creating a locally high concentration of POA) cocrystallize with wax molecules and modify the oil rheology. Li et al 97 prepared an EVA/nano-SiO 2 hybrid using EVA with different vinyl acetate contents (28,33, and 38 wt %) and used them as flow improvers for Daqing waxy crude oil and model oil. They found that the nanohybrid performs better in depressing pour points than the pure polymer (Figure 6).…”

“…Several methods are available for solving flow assurance problems in transportation pipelines for waxy crude oil that can be categorized as mechanical, thermal, or chemical methods . The application of low-cost chemical additives in waxy crude oil pipelines is economical and effective. , The utilization of polyethylene as a chemical additive in waxy oil dates back to 1944, when it was used for inhibiting wax formation. , Today, a spectrum of additives such as polymers, − surfactants, , nanocomposites, , organic solvents, oil-based compounds, , liquid crystals, and others are utilized as flow improvers. − The main objective of additives for waxy crude oil is to interrupt the crystallization of nonpolar wax molecules. They may also disperse asphaltene aggregates present in oil or dissolve the precipitated wax crystals.…”

Redox- and pH-responsive emulsions based on TiO2 nanoparticles and ferrocene derivates

“…Although highly stable Pickering emulsions show excellent applications in cosmetics and food field, demulsification is also of great importance in some situations, such as crude oil transport, interfacial catalysis, and emulsion polymerization. 11,[18][19][20] Therefore, the stimuli-responsive Pickering emulsions have attracted much attention recently. 21,22 As we all know, triggers such as pH, CO 2 , redox, ion, magnetic field and light have been widely used for constructing responsive Pickering emulsions.…”