Janus Particle Preparation through UV-Induced Partial Photodegradation of Spin-Coated Particle Films

Abstract

Janus particles contain two or more chemical properties typically on opposing faces. With various property combinations possible, there are several potential applications, such as surfactants and drug delivery. However, scaling up the particle production process at reasonable cost is a limiting factor, and the method reported here aims to circumvent this issue. The process is based on a top-down destructive strategy that consists of two steps. Photocatalytic titanium dioxide particles prefunctionalized with a surface coating were assembled as particle films via spin-coating on a substrate. The particle films were placed directly under an ultraviolet light source, which induced the photodegradation of the surface coating only on the particle surfaces exposed to the light. The generated Janus particles were amphiphobic–amphiphilic in character. The Janus particles had a theoretical Janus balance close to ideal and remained attached at a hexane/water interface after disruption. They were able to make Pickering emulsions of water in silicone oil with a low energy input. The reported method may be easily scaled up to facilitate the production of gram-scale yields. The use of UV is clean and efficient and can be applied to semiconductor particles with surface coatings that are susceptible to photodegradation, making this method highly versatile.

Development of Janus Particles as Potential Drug Delivery Systems for Diabetes Treatment and Antimicrobial Applications

“…“Janus equilibrium” is another factor that must be considered in the characterization of Janus particles and remains a major challenge in the preparation of perfect biphasic Janus particles with the desired anisotropic shape [ 141 ]. Hence, research interest has shifted to the development of asymmetric Janus particles, such as colloidal structures with multiple patches or compartments that do not exhibit complementary biphasic conformations [ 142 ]. The geometry of Janus particles is also a crucial parameter that needs to be controlled during the synthesis process to produce the effective ratios of each compartment for different applications [ 143 ].…”

Engineering surface patterns on nanoparticles: new insights into nano-bio interactions

“…In a short time, they achieved a coverage rate of 43.49% in the film. 102 However, the subtractive method is currently not mature enough, and further studies are encouraged to achieve a high-yield synthesis of Janus particles of interest.…”