Preparation method of dumbbell-shaped janus colloidal particles

Abstract

The preparation method of the dumbbell-shaped Janus colloidal particles comprises the following steps: stirring and dispersing the surfactant in deionized water; under the protection of nitrogen, ultrasonically treating the vinyl siloxane and the reaction monomer containing double bonds for 5-30min Add the mixture into a four-neck flask, stir evenly, raise the temperature to a reaction temperature of 40-75°C, add an aqueous initiator solution dropwise to the system, and continue the reaction at the reaction temperature for 5-10 hours, then stop stirring, and cool to room temperature to obtain a stable White emulsion, dumbbell-shaped Janus colloidal particles were obtained after centrifugal washing. The method has the characteristics of easy production control, the obtained latex can be used directly, and the residual monomer is easy to remove, and the reaction is carried out in an aqueous medium without any organic solvent, the whole reaction process is safe and non-toxic, the operation is simple, and mass production can be realized Monodisperse Janus particles.

Description

technical field [0001] The invention belongs to the field of material chemistry, in particular to a method for preparing colloidal particles with a dumbbell-shaped Janus structure. Background technique [0002] In 1991, P.G. deGennes borrowed the word Janus (two-faced god) for the first time to describe the same particle with different chemical composition or properties in his Nobel Prize Lecture. The term was later used figuratively to refer to non-centrosymmetric particles with different properties, known as Janus particles. Due to its asymmetry in nature, Janus particles will inevitably cause differences in physical and chemical properties. This difference makes them useful in functional surfactants, self-assembly and molecular recognition, electronic paper, photoelectric biosensors, and multifunctional magnetic asymmetric materials. , anti-reflection film and electronic devices, photonic crystals, catalysts and other fields have shown broad application prospects, and ha...

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Problems solved by technology

However, there are some problems in so many preparation methods, which limit the preparation and application of Janus particles. For example, the Pickering emulsion method uses the distribution state that part of the surface of the inorganic solid particle is immersed in the oil phase and the other part of the surface is immersed in the water phase. Prepare Janus particles, but the biggest problem is that the rotation of solid particles at the interface cannot be prevented. The rotation will modify the surface of the entire particle and Janus particles cannot be obtained; the phase separation method mainly uses the different compatibility between substances, by controlling the conditions Phase separation occurs between substances to form Janus particles. This method is simple in process and large in output, but the particle size distribution obtained is relatively wide. In the case of relatively strict particle size requirements, multiple particle size classifications are required; microfluidic method The prepared Janus particles have a large particle size, and it is difficult to obtain submicron or nanometer Janus particles

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