Gold nanoparticles stabilized by an amphiphilic pillar[5]arene: preparation, self-assembly into composite microtubes in water and application in green catalysis

Gold nanoparticles stabilized by an amphiphilic pillar[5]arene (AP5) are prepared. They can be decorated on the surfaces of microtubes prepared from self-assembly of AP5 to form template composite microtubes (TCMTs). They can also be used in the fabrication of self-assembled composite microtubes (SCMTs) in water without any external assistance. A combination of UV-Vis spectra, Fourier transform-infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, X-ray diffraction measurements, and thermogravimetric analysis is used to confirm the formation of these composite microtubes. The SCMTs are stable at high temperature, with strong acid, with strong base, and under sonication. Interestingly, the properties of SCMTs are different from those of TCMTs and SCMTs can be used in green catalysis with a yield loss within 3% for 20 cycles. This work provides a new method to create amphiphilic nanoparticles for the fabrication of novel functional materials and devices by self-assembly.