A facile method of synthesizing amphiphilic Janus silica nanoparticles (SiNPs) with bicompartment polymer brushes is presented in this article by combining "polymer single-crystal templating". (pSCryT) and "grafting from" techniques. First, alkoxysilane-terminated poly(epsilon-caprolactone) (PCL-SiOR) single crystals were prepared using a self seeding method. Silica nanoparticles (40-50 nm) were immobilized onto the surface of single crystals. Subsequent surface initiated atom transfer radical polymerization (SI-ATRP) of N-isopropylacrylamide was carried out on the exposed surface of SiNPs. Dissolution of the polymer single crystal led to Janus nanoparticles with amphiphilic, bicompartment poly(epsilon-caprolactone) (PCL) and poly(N-isopropylacrylamide) (PNIPAM) polymer brushes. The Janus nature of the particle and its detailed characteristics were studied using a variety of techniques including Fourier transform infrared spectroscopy, H-1 nuclear magnetic resonance spectroscopy, transmission electron microscopy, and thermogravimetric analysis. These Janus nanoparticles can be readily dispersed M Water at room temperature, and because of the lower critical solution temperature (LCST) behavior of PNIPAM brushes in water, Janus nanoparticles exhibit thermo-induced assembly with interesting molecular weight and concentration dependence. Compared with symmetrical PNIPAM-coated SiNPs, Janus particles showed a lower LCST temperature and a much narrower transition range.