Periodic Mesoporous Organosilicas Consisting of 3D Hexagonally Ordered Interconnected Globular Pores

Abstract

A new family of periodic mesoporous organosilicas with 100% E-configured ethenylene-bridges and controllable pore systems is presented. 2D hexagonally ordered hybrid nanocomposites consisting of cylindrical pores are obtained, of which some are filled with solid material. The architectural composition of these hybrid materials can be accurately controlled by fine-tuning the reaction conditions; that is, there is a unique correlation between the reaction mixture acidity and the amount of confined mesopores. This correlation is related to the filling of the pores with solid material whereby the length of the pore channels can be tailored. Hereby the mesophase either shifts toward long-ranged 2D hexagonally ordered open cylinders or toward 3D hexagonally ordered interconnected spheres. The synthesis of these organic−inorganic hybrid composites is straightforward via the direct condensation of E-1,2-bis(triethoxysilyl)ethene, in the presence of pluronic P123. The true nature of these periodic mesoporous organosilicas is disclosed by means of nitrogen gas physisorption, nonlocal density functional theory, SAXS, TEM, and electron-tomography.

Novel method to synthesize highly ordered ethane-bridged PMOs under mild acidic conditions: Taking advantages of phosphoric acid

“…Most likely, the acidity of the synthesis mixture is the decisive factor, leading to an excessive polycondensation rate of the silica precursor, relative to the surfactant self-organization. In this case, besides the selfassembling process, the excessive polycondensation of the silica precursor causes the formation of disordered amorphous materials, filling parts of the mesoporous channels [28,29]. Another prominent feature of the N 2 adsorptionedesorption isotherms for the samples synthesized at pH < 1.5 is the second hysteresis loop at a relative pressure larger than 0.80, which implies the existence of secondary mesopores or macropores.…”

Periodic Mesoporous Organosilicas: from simple to complex bridges; a comprehensive overview of functions, morphologies and applications

“…78 Ethene-PMOs prepared by special templating; spheres and particles. Only a few examples of morphology control in ethene-PMOs have been reported.…”

Process technology scaling in an increasingly interconnect dominated world

“…This can be achieved using several emerging self assembly methods for film deposition. [4] Figure 7 demonstrates a 58% porous film with ~1nm ordered pores, a k-value of 1.95, and a modulus exceeding unordered films at the same porosity.…”