Nano-scale control of composite polymer films by mass-controlled layer-by-layer sequential adsorption of polyelectrolytes

The mass of polyelectrolyte films adsorbed onto a surface during the deposi tion of a thin polymer film by a layer-by-layer sequential adsorption proce ss was systematically controlled using a feedback system with a computer. F or the deposition process, a quartz crystal microbalance (QCM) with an inte grated oscillation circuit was attached to the arm of an automatic slide st ainer and the frequency shift during adsorption or rinsing of the polyelect rolytes was monitored by a computer attached to a frequency counter. By fee ding back the data acquired by the in situ QCM measurement, the mass of mat erial deposited was controlled and a high quality self-assembly Firn was pr oduced. This is termed mass-controlled layer-by-layer sequential adsorption . The accuracy of the layer thickness in the multiplayer film was found to be approximately 1 nm. Copyright (C) 2000 John Wiley & Sons, Ltd.