Innovation in Layer by Layer Assembly.
Methods for depositing thin films are important in generating functional materials for diverse applications in a wide variety of fields. Over the last half century, the layer by layer assembly of nanoscale films has received intense and growing interest. This has been fueled by innovation in the available materials and assembly technologies, as well as the film characterization techniques. In this Review, we explore, discuss, and detail innovation in layer by layer assembly in terms of past and present developments, and we highlight how these might guide future advances. A particular focus is on conventional and early developments that have only recently regained interest in the layer by layer assembly field. We then review unconventional assemblies and approaches that have been gaining popularity, which include inorganic/organic hybrid materials, cells and tissues, and the use of stereocomplexation, patterning, and dip pen lithography, to name a few. A relatively recent development is the use of layer by layer assembly materials and techniques to assemble films in a single continuous step. We name this "quasi" layer by layer assembly and discuss the impacts and innovations surrounding this approach. Finally, the application of characterization methods to monitor and evaluate layer by layer assembly is discussed, as innovation in this area is often overlooked but is essential for development of the field. While we intend for this Review to be easily accessible and act as a guide to researchers new to layer by layer assembly, we also believe it will provide insight to current researchers in the field and help guide future developments and innovation.
Chemical reviews