Preparation of Self-Assembled Nanoparticle–Polymer Hybrids from Modified Silica Nanoparticles and Polystyrene-Block-Polyacrylic Acid Vesicles via the Co-Precipitation Method

Abstract

Nanoparticle–polymer hybrids are becoming increasingly important because seemingly contrasting properties, such as mechanical stability and high elasticity, can be combined into one material. In particular, hybrids made of self-assembled polymers are of growing interest since they exhibit high structural precision and diversity and the subsequent reorganization of the nanoparticles is possible. In this work, we show, for the first time, how hybrids of silica nanoparticles and self-assembled vesicles of polystyrene-block-polyacrylic acid can be prepared using the simple and inexpensive method of co-precipitation, highlighting in particular the challenges of using silica instead of other previously well-researched materials, such as gold. The aim was to investigate the influence of the type of modification and the particle size of the silica nanoparticles on the encapsulation and structure of the polymer vesicles. For this purpose, we first needed to adjust the surface properties of the nanoparticles, which we achieved with a two-step modification procedure using APTES and carboxylic acids of different chain lengths. We found that silica nanoparticles modified only with APTES could be successfully encapsulated, while those modified with APTES and decanoic acid resulted in vesicle agglomeration and poor encapsulation due to their strong hydrophobicity. In contrast, no negative effects were observed when different particle sizes (20 nm and 45 nm) were examined.

Impact of the Nano-SiO2 Particle Size on Oil Recovery Dynamics: Stability, Interfacial Tension, and Viscosity Reduction

“…It finds extensive use in several domains, including polymer sciences, optics, medicine, thermal science, and the petrochemical industry, − among other fields. Presently, nano-SiO 2 can be synthesized through dry methods, such as gas-phase and arc methods, or wet methods, including vapor deposition, inverse microemulsion, precipitation, and Stöber methods . Among these, the Stöber method is favored for its gentle conditions, simple equipment, operational ease, cost-efficiency, and ability to produce SiO 2 microspheres with excellent dispersion and purity.…”

Influence of Process Parameters on the Kinetics of the Micelle-to-Vesicle Transition and Ripening of Polystyrene-Block-Polyacrylic Acid

“…The packing parameter of a polymer molecule, and thus, the morphology of the block copolymer structure, should, however, by no means be regarded as fixed. Different authors have described, the effects of the type and amount of solvent and antisolvent [ 6 , 7 ], the composition of the block copolymer [ 8 , 9 ], and the concentration of the polymer, as well as the presence of additives [ 9 ].…”

“…In addition to the above-mentioned structures, much more complex morphologies have been observed, for example, as metastable transition morphologies [ 10 ]. Therefore, many different and partly complex morphologies have been obtained from block copolymers, such as spherical or cylindrical micelles [ 7 , 8 , 11 ], disc-like micelles [ 12 , 13 ], toroids [ 14 ], spherical particles with gated nanopores [ 15 ], vesicles (e.g., genus vesicles, multi-compartment vesicles, Janus vesicles, and onion-like vesicles) [ 16 ], lamellar structures, network-like structures [ 7 , 11 ], helical structures [ 17 ], and many more [ 18 ] could be revealed so far. This diversity results in many potential applications, such as in the fields of nanocomposites [ 7 , 19 ], biomaterials [ 20 ], drug delivery systems [ 21 , 22 , 23 , 24 ], nanoreactors [ 25 ], or as self-healing materials [ 26 ].…”