Light-Triggered Release from Pickering Emulsions Stabilized by TiO₂ Nanoparticles with Tailored Wettability

Abstract

In this work, a new strategy for developing light-triggered Pickering emulsions as smart soft vehicles for on-demand release is proposed. Initially, UV-induced tailored wettability allows anchoring of TiO2 nanoparticles at the interface to prepare stable water in oil emulsions. Such emulsions show the efficacy of microencapsulation and controlled release by demulsification due to the hydrophilic conversion of the TiO2 nanoparticles using a noninvasive light irradiation trigger. A molecule of interest is selected as a model cargo to quantitatively evaluate the as-prepared Pickering emulsions for their encapsulation and release behaviors. Moreover, light-responsive emulsion destabilization mechanism is studied as a function of particle concentration, light wavelength, and light intensity, respectively, determined by drop diameter evolution and droplet coalescence kinetics plots. For consideration of application in life sciences, Pickering emulsions sensitive to visible light are also established based on nitrogen doping of TiO2 nanoparticle emulsifiers.

Enzyme-Loaded Mesoporous Silica Particles with Tuning Wettability as a Pickering Catalyst for Enhancing Biocatalysis

“…Notably, the TCA of 95° of C8 is very close to 90°. Interestingly, the result is similar to that in our previous studies, the C7 coating is having the more preferred TCA (105.5°) than C6 (108.5°) and C12 (140.5°), thus C7 is the optimum condition for modifying the TiO2 particles to prepare stable Pickering emulsions [38]. We can deduce that, with the increase of the carbon chain length, there is always one Cn (n is the number of carbon element) coating having an optimum contact angle (close to 90°) which means the competition of hydrophilic/lipophilic interaction to the particles at the paraffin oil-water interface achieve a balance.…”

“…Surface wettability of particles is thought to be crucial in stabilizing Pickering emulsions. In our previous studies, the most stable Pickering emulsion with the relatively large interfacial area is formed when the three-phase contact angle (TCA) of particles is close to 90 • [37,38]. To get the optimum condition, silylating agents with different carbon chain length (C0, C3, C6, C8, C10, C12) is used to modify the LMSPs.…”

A Close Look at the Structure of the TiO2-APTES Interface in Hybrid Nanomaterials and Its Degradation Pathway: An Experimental and Theoretical Study

“…Light irradiation of silane-functionalized TiO 2 can also be used as a trigger to activate the on-demand controlled release of active substances from stimulus-responsive Pickering emulsions. 21 , 22 …”

Effect of Pickering emulsion on the mechanical performances and fracture toughness of epoxy composites

“…Pickering emulsion, which is stabilized by ultrafine particles (for example colloidal silica) of sizes from a few nanometers to hundreds of micrometers, has attracted widespread interest in areas such as pharmaceutics, high‐performance polymer nanocomposites, environment protection, phase change materials, and functional materials . Some of the used stabilized particles are nanocelluloses, TiO 2, cellulose nanocrystals, and silica nanoparticles . It is well known that the nanoparticle stabilizers are adsorbed onto the interface between the two phases and the solutes are well dispersed and homogenized in solvents.…”