Ultrathin, freestanding polymer hybrid film with macroscopic sizes and molecular thicknesses have received significant interest due to their applications as functional devices, microsensors or nanoactuators. Herein, a 2D Janus hybrid of polymer‐grafted carbon nanotubes/graphene oxide (CNTs/GO) thin film is fabricated using microcontact printed CNTs/GO as photo active surface to grow polymer brushes by self‐initiated photografting and photopolymerization selectively from one side of CNTs/GO film. This achieved 2D Janus hybrid materials with grafted polymer layer as insulative carpet and supported CNTs/GO thin film as conductive element have the potential application as flexible and miniature electric carpet for heating micro‐/nano devices locally.

High fidelity and regularity structures of nanoscale materials has opened up new opportunities for developing miniaturized devices. A simple yet robust approach of magnetic field assisted controlled evaporative self-assembly (CESA) is developed to achieve Fe 3 O 4 nanoparticle (NP) micro-and nanopatterns in a two dimensional (2D) direction. In the magnetic field assisted CESA process, the selfassembly morphology can be well controlled by varying extrinsic and intrinsic variables such as temperature, external magnetic field, and concentration of Fe 3 O 4 NPs. Under the optimized magnetic field rotation frequency and temperature, 2D self-assembly of Fe 3 O 4 NPs can be well realized. In addition, as photoactive sites, double bonds on the surface of Fe 3 O 4 NPs allow the growth of polymer brushes by self-initiated photografting and photopolymerization (SIPGP), and the further achievement of free-standing magnetic composite films with well-defined patterns. † Electronic supplementary information (ESI) available: The SEM, optical, AFM images of Fe 3 O 4 nanoparticles, Fe 3 O 4 nanoparticles patterns and free-standing lm. See

ABSTRACT:A simple yet robust approach was exploited to fabricate large-scaled patterned polymer brushes by combining controlled evaporative self-assembly (CESA) in a confined geometry and self-initiated photografting and photopolymerization (SIPGP). Our method was carried out without any sophisticated instruments, free of lithography, overcoming current difficulties in fabricating polymer patterns by using complex instruments.