Polyrotaxane‐Mediated Self‐Assembly of Gold Nanospheres into Fully Reversible Supercrystals

Abstract

The use of a thiol-functionalized nonionic surfactant to stabilize spherical gold nanoparticles in water induces the spontaneous formation of polyrotaxanes at the nanoparticle surface in the presence of the macrocycle α-cyclodextrin. Whereas using an excess of surfactant an amorphous gold nanocomposite is obtained, under controlled drying conditions the self-assembly between the surface supramolecules provides large and homogenous supercrystals with hexagonal close packing of nanoparticles. Once formed, the self-assembled supercrystals can be fully redispersed in water. The reversibility of the crystallization process may offer an excellent reusable material to prepare gold nanoparticle inks and optical sensors with the potential to be recovered after use.

Optimization and Insights into the Mechanism of Formation of Mechanically Interlocked Derivatives of Single‐Walled Carbon Nanotubes

“…[13] The mechanical bond provides rotaxanes with unique dynamic properties that have been exploited in the synthesis of molecular machinery. [14][15][16] Most examples of rotaxanes reportedt o date comprise small-molecule organicc omponents,b ut there is ag rowing interest in mechanically interlocked materials, such as polyrotaxanes, [17][18][19][20] rotaxanated metal organic frameworks, [21][22][23] and organic-inorganic rotaxanehybrids. [24][25][26] We have recently introduced the mechanicalb ond as an ew tool for the chemical derivatization of carbon nanotubes, bringingt ogether the fields of SWNT chemistry and MIMs.…”

Recent progress on colloidal metal nanoparticles as signal enhancers in nanosensing

“…With the aim of solving that issue, GuerreroMartínez and co-workers have developed methods of syntheses of large and homogeneous substrates of supercrystals with close packing of AuNPs following supramolecular [54] and colloidal [23,24] strategies. Such plasmonic substrates show highly reproducible LSPR bands within long-range areas (~cm 2 ) of the substrates (Fig.…”

“…4). Within a supramolecular context, the use of thiol-functionalized nonionic surfactants to stabilize AuNPs in water induces the spontaneous formation of polyrotaxanes at the nanoparticle surface in the presence of the macrocycle α-cyclodextrin [54]. The self-assembly between the surface supramolecules provides large and homogeneous supercrystals with hexagonal close packing of nanoparticles (Fig.…”

“…(For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.) From Refs [54]. and[24].…”

Concentration-dependent platinum nanoassemblies with morphology-controlled electroactivity and high durability for direct methanol fuel cells

“…[16][17] In previous literatures, surfactants are crucial in the formation of the self-assembled nanostructures. [18][19] It is generally believed that the building blocks for oriented aggregation/attachment are usually nanoparticles with surfaces stabilized by an organic coating, and weakly protected nanoparticles often undergo entropy-driven random aggregation. 20 However, excessive surfactants are difficult to be removed from as-obtained nanoassemblies and responsible for the dramatic reduction of properties.…”