Phosphoric acid oleyl ester (mono- and di- ester mixture)

• CAS: 37310-83-1
• Catalog Number: ACM37310831-4
• Category: Organic Phosphates
• Solubility: Soluble in ethanol, benzene, and acetone.
• Storage: Room temperature (recommended in a cool and dark place, <15°C)
• Color: White or colorless to brown
• MDL Number: MFCD00135103
• Physical State: Liquid
• Pubchem SID: 87574150

Case Study

Oleyl Phosphate as a Surface Modifier for Low-Photoreactivity TiO2/Ce2O3 UV-Shielding Nanofillers

Tian, Xiangyu, et al. Chemical Engineering Journal 477 (2023): 146962.

Titanium dioxide (TiO2) is an inexpensive, effective UV absorber, but two problems limit its use in durable, transparent polymer products: strong photocatalytic activity and poor compatibility/dispersion.
Oleyl phosphate was employed as an organic surface treatment agent for newly synthesized TiO2/Ce2O3 heterojunction nanoparticles. The nanoparticles were first created via an in-situ solvothermal process to form a unique heterostructure designed to intrinsically lower photocatalytic activity. Subsequently, Oleyl Phosphate was applied to modify the surface of these nanoparticles.
· Particle size & dispersion: Crystalline-amorphous TiO2/Ce2O3 heterojunctions averaged ~15 nm and, after OP modification, were near-monodisperse in organic solvent and readily blended into fluorocarbon resin.
· Dramatic suppression of photocatalysis: the apparent dye-degradation rate constants (k) for the optimized TiO2/Ce2O3-3% sample were ~34× (RhB), ~28.5× (MB) and ~24.8× (RR-120) lower than those of pure TiO2, demonstrating a very large reduction in photocatalytic activity.
· Mechanistic insight: experimental characterization and DFT indicate that photogenerated carriers migrate and accumulate in the amorphous Ce2O3 regions (defect-rich), promoting faster recombination and reducing the carriers' redox potential - the physical origin of reduced photocatalytic oxidation.
· Coating performance: OP-functionalized particles formed transparent OP-TiO2/Ce2O3 / fluorocarbon hybrid coatings that combine effective UV absorption with suppressed photocatalytic degradation and good optical clarity.

Employing Oleyl Phosphate as a Covalent Coupling Agent for High-Refractive-Index TiO2/PMMA Optical Films

Fujita, Masato, et al. Journal of Nanomaterials 2015.1 (2015): 297197.

The development of polymer-based hybrid thin films with high refractive indices and excellent optical transparency is crucial for advanced optics and photonics applications. This study investigated the use of oleyl phosphate (OP) as a surface modifier to chemically tether and compatibilize TiO2 nanoparticles, enabling the fabrication of high-performance, transparent hybrid films via an ex-situ process.
Application & Process: Oleyl phosphate was covalently grafted onto the surface of TiO2 nanoparticles via a reaction in a methanol dispersion, forming Ti-O-P bonds. The modified nanoparticles (OP_TiO2) were purified to remove unreacted OP and re-dispersed in toluene. These OP_TiO2 dispersions were then mixed with a PMMA solution in toluene. Hybrid thin films were fabricated by spin-coating the homogeneous mixture onto glass substrates, followed by thermal treatment to form the final composite film with TiO2 volume fractions up to 20%.
Key Results:
· The oleyl groups from OP effectively suppressed nanoparticle aggregation. OP_TiO2 formed a stable, homogeneous dispersion in toluene with a median particle size of 16.1 nm, suitable for minimizing Rayleigh scattering.
· The resulting OP_TiO2/PMMA hybrid thin films exhibited outstanding optical clarity, with transmittance values exceeding 89.0% at 633 nm wavelength, even at a high TiO2 loading of 20 vol%.
· The refractive index of the hybrid films increased systematically with the TiO2 volume fraction. The film containing 20 vol% OP_TiO2 achieved a high refractive index of 1.86, demonstrating effective loading of the high-index filler. TEM imaging confirmed the uniform dispersion of individual TiO2 nanoparticles within the PMMA matrix, without significant agglomeration.

Oleyl Phosphate Enables Hierarchical Supercrystalline Iron-Oxide Nanocomposites

Domènech, Berta, et al. Scientific reports 9.1 (2019): 3435.

In this study, oleyl phosphate (a mixture of mono- and di-esters) was employed as the surface-modifying agent for monodisperse iron oxide nanoparticles. The modification process involved reacting the nanoparticles with Oleyl Phosphate in toluene over an extended period, followed by thorough washing and purification to achieve a defined organic content on the particle surface. The resulting organically-modified ceramic nanoparticles were then dispersed in toluene, and their self-assembly was initiated by the slow evaporation of the solvent at room temperature over several days. The dried sediment was subsequently consolidated via warm uniaxial pressing to form the final bulk material.
The use of oleyl phosphate as a ligand was instrumental in achieving controlled hierarchical organization:
· By varying the local organic-phase concentration during drying, the researchers obtained either (a) uniformly supercrystalline nanocomposites or (b) hierarchically structured supercrystalline materials. Importantly, when the organic content exceeded a critical threshold, hierarchical architectures formed consistently.
· Hierarchical levels: Level 0: individual OP-coated ceramic nanoparticles; Level 1: nanoparticles organized into supercrystals adopting face-centered-cubic superlattices; Level 2: supercrystalline units assembled into micrometer-scale granules (up to hundreds of micrometers), which became the building blocks of the final millimeter-scale material.
· Uniform supercrystalline bulk materials show promise for high hardness, stiffness and strength, while organic-rich, hierarchical composites provide additional avenues to tailor fracture toughness and mechanical response by design.