Inorganic Micelles (Hydrophilic Core@Amphiprotic Shell) for Multiple Applications

Abstract

Very little attention has been focused on the purifi cation of water-soluble pollutants after oil/water separation. [ 4 ] Thus, there is considerable interest in developing novel and facile methods for the simultaneous separation of oil from water and purifi cation of water-soluble pollutants.The practical application of organic micelle catalysts that utilize hydrophilic/ hydrophobic interfaces has been limited by several disadvantages. For example, the stability of organic micelles depends on many parameters, such as the solvent polarity, critical micelle concentration, and reaction conditions, such as pH, water/oil ratio, and temperature. [ 10,11 ] Due to the narrow range of stability of organic micelles, the synthesis of inorganic micelles that have hydrophilic/hydrophobic interfaces, large surface areas, high porosities, tunable surfaces, and high recyclability has recently attracted some attention. [ 12,13 ] For example, Lin and co-workers reported a simple route to hierarchically assembling micelles and inorganic nanoparticles. [ 14 ] Yang and co-workers prepared functionalized mesoporous silica spheres consisting of a hydrophobic core and a hydrophilic micellar shell. [ 15 ] As a fi rst example, Alivisatos and co-workers recently reported resin templates based on the synthesis of inorganic micelles with a hydrophilic cavity and a hydrophobic surface and its application as a catalyst in the bromination of alcohol. [ 16 ] There is still considerable interest in developing novel methods for the exploration of interior/ exterior-functionalized, superhydrophobic, and nanostructured inorganic micelles. To fulfi ll the requirements of oil/water separation and inorganic micellar catalysis mentioned above, the development of hierarchical nanomaterials that have a hydrophilic interior and superhydrophobic/hydrophilic (amphiprotic) exterior is highly desirable, offering signifi cant potential for multiple applications. To the best of our knowledge, this report is the fi rst example of the synthesis of nanomaterials that have a hydrophilic core and amphiprotic shell for multiple applications, such as amphiprotic catalytic reactions, oil/water separation and pollutant purifi cation, and enzyme immobilization with signifi cant stability and effi cient recyclability.Herein, we present the preparation and multiple applications of superhydrophobic hollow SiO 2 micelles (SHSMs) with hydrophilic cores and amphiprotic (superhydrophobic/hydrophilic) shell structures that act as "all-in-one" smart nanomaterials. Our SHSMs are better than hydrophilic@hydrophobic micelles prepared using previously reported methods for several reasons: (i) the polyallylamine hydrochloride (PAH) chains were extended and survived from the core to the shell even Inorganic Micelles (Hydrophilic Core@Amphiprotic Shell) for Multiple Applications Md. Shahinul Islam , Won San Choi , * Sun Ha Kim , Oc Hee Han , and Ha-Jin Lee * A facile approach for synthesizing superhydrophobic hollow silica micelles (SHSMs) with hydrophilic cores and amphiprotic (supe...

A Potential Amphiprotic Sponge with a Controlled Release Characteristic of Protons on Demand for Oil/Water Separation and Acid/Base Neutralization

“…Figure a shows a schematic illustration of the one‐step switching of the superhydrophilic melamine formaldehyde sponge (SHphi‐MFS) to a superhydrophobic MFS (SHpho‐MFS) with pH tuning ability that was simply prepared by ultrasound treatment of the SHphi‐MFS at a low pH. The SHphi‐MFS has been used as a base material for oil/water separation due to its easy surface modification and excellent durability . The rate of switching the sponge from hydrophilic to hydrophobic can be controlled by varying the ultrasound treatment times (Figure b).…”

“…Because oil/water mixtures produced from industries occasionally contain toxic organic compounds and heavy metals, there is an increasing demand for simultaneous oil/water separation and pollutant remediation . Oil/water separators loaded with catalysts decompose toxic organic pollutants in water after oil/water separation is achieved . Other cases include separators with an adsorption function to adsorb heavy metals or toxic organic compounds in water after the oil/water separation .…”

One-Step Synthesis of Environmentally Friendly Superhydrophilic and Superhydrophobic Sponges for Oil/Water Separation

“…Since oil/water mixtures produced from industries occasionally contain heavy metals and toxic organic compounds, there is an increasing demand for oil/water separation and pollutant remediation [15,16,17,18,19,20,21,22,23]. Nanomaterials have been widely used as component materials for synthesis of superhydrophilic or superhydrophobic materials because the surface morphology and functionality of the abovementioned materials can be tuned by incorporation of nanomaterials [15,16,17,18,19,20,21,22,23]. Nanocatalyst-loaded oil/water separators decompose toxic organic pollutants in water after oil/water separation is achieved [15,16,17].…”

“…Nanomaterials have been widely used as component materials for synthesis of superhydrophilic or superhydrophobic materials because the surface morphology and functionality of the abovementioned materials can be tuned by incorporation of nanomaterials [15,16,17,18,19,20,21,22,23]. Nanocatalyst-loaded oil/water separators decompose toxic organic pollutants in water after oil/water separation is achieved [15,16,17]. Other separators with an adsorption function to adsorb heavy metals or toxic organic compounds in water after the oil/water separation are also reported [18,19,20,21,22,23].…”

Highly selective and recyclable hydrogenation of α‐pinene catalyzed by ruthenium nanoparticles loaded on amphiphilic core–shell magnetic nanomaterials

“…In recent years, magnetic nanomaterials have been widely applied in many important fields such as medicine control and storage, adsorption stripping, and catalysis, due to their easy separation, large specific surface area, interfacial effect, and mesoporous effect . Adjusting the hydrophilicity and hydrophobicity of magnetic materials is very important for their performance . Undoubtedly, amphiphilic magnetic materials are more attractive in some applications than hydrophilic or hydrophobic congeners.…”