Takayoshi Sasaki and colleagues at the National Institute of Materials Science, Tsukuba, and co-workers from the University of Tsukuba, Japan have prepared rare earth hydroxide films by trapping micrometer-sized crystals at a hexane-water interface and then transferring them to a substrate. The resulting film is of much better quality in terms of orientation and coverage than films fabricated by traditional methods, such as solvent evaporation or spin-coating. 

                        

In situ the films show anion-exchange properties at room temperature allowing modification and further design. In addition the films exhibit photoluminescence properties which may have potential applications in optical devices or luminescence probes for chemical sensors. 
The motivation for Sasaki and his team was to develop a method that could synthesise well-organised functional material films that could have a wide range of applications. 
The next challenge is to 'control the lateral alignment of the crystals, then much better films of closely packed crystals may be produced. Such films would exhibit enhanced physical properties,' says Sasaki. 
Michael Brown