Designed synthesis of nanostructured siloxane–organic hybrids from amphiphilic silicon-based precursors

Abstract

This paper reports on recent progress in the synthesis of nanostructured siloxane-organic hybrids based on the self-assembly of amphiphilic silicon-based precursors. A variety of ordered hybrid materials have been obtained by molecular design of the precursors. Alkoxysilanes and chlorosilanes with covalently attached hydrophobic organic tails are hydrolyzed to form amphiphilic molecules containing silanol groups, leading to the formation of layered (lamellar) structures. Transparent and oriented thin films of lamellar hybrids were prepared by the reaction in the presence of tetraalkoxysilane. In addition, the design of molecules having alkyl chains and large oligosiloxane heads led to the formation of mesophases consisting of cylindrical assemblies, providing a direct pathway to ordered porous silica. The synthesis, structural features, and formation processes of these hybrid mesostructures are discussed.

Bridged Silsesquioxanes with Organic Domains Self‐Assembled as Functionalized Molecular Channels

“…This produces a compact organic structure that defines the surface of the channel (e.g., the lateral interchain distance of closely packed alkyl chains is 0.42 nm). [44] It is interesting to remark that the size of the aspirin molecule enables to place it inside the organic channels forming H-bonds with tertiary amines, OH and/or ether groups. The aspirin incorporated to the hybrid material should be present in both ordered and disordered domains.…”

Sol-Gel Synthesis of a Nanostructured Hybrid Material from an Organosiloxane Oligomer with a Terminal Phenyl Group

“…7 -10 We have reported the formation of multilayered hybrids from alkyltrialkoxysilanes by exploiting the amphiphilic nature of hydrolyzed species. 8 Organically-bridged bis-alkoxysilanes with the general formula of Rö O 3 Si-R-Si ORö 3 have also been used to produce lamellar hybrids, 10 which is based on the weak interactions p-p interactions, hydrogen bonding, etc. between bridging R groups.…”

Metallosomes: artificial cell membranes with ultrathin metallic surfaces derived from cationic cerasomes through electroless plating

“…9) Then, the negatively-charged PdCl [2][3][4] species were able to bind all over the surface of the positively-charged cerasomes. The immobilization of many catalytic sites distributed homogeneously on the cerasome surface was expected to realize a complete surface coating by the Ni layer.…”

“…The electroless plating of cerasomes was performed by firstly binding PdCl [2][3][4] ions onto the cationic membrane surface through electrostatic interactions, then subsequently reducing this precursor catalyst to Pd(0), and finally, depositing a layer of metal onto the cerasome surface using an appropriate plating bath. While metallosomes coated with an ultrathin Ni layer could be prepared by electroless Ni plating of cationic cerasomes, it was not possible to derive the corresponding Ni-coated vesicles from the liposomal membranes formed with cationic peptide lipids under similar plating conditions, thus reflecting the difference in the morphological stability of these vesicles.…”

“…The binding site is localized on the vesicular surface in the case of the latter method. Under the current condition of step 1, the Pd ion species existed mainly as PdCl [2][3][4] . 22) On the other hand, the cerasomes were positively charged under the same condition, as evidenced by the existence of quaternary ammonium groups in lipid 1.…”