Facile and Efficient Approach to Speed up Layer-by-Layer Assembly: Dipping in Agitated Solutions

Abstract

A facile and efficient approach has been developed to speed up the fabrication of LBL films through sequential dipping in vigorously agitated solutions. By this agitated-dipping (AD) LBL technique, the multilayer films of PAH and PSS were fabricated. The resulting films were explored by UV-vis spectroscopy, X-ray reflectivity, and AFM. Meanwhile, the comparison of the AD and conventional LBL films was made, which demonstrated that AD LBL can decrease dipping time by more than 15 times without reducing film quality remarkably. In addition, to verify the generality of AD LBL, we studied the AD LBL films of PDDA/PSS and PAH/PAA preliminarily as well. AD LBL promotes the efficiency of conventional LBL greatly while preserving its most advantages, such as simplicity, cheapness, precise control, universality in substrates, recycling use of sample solutions, and so on. It would be a promising alternative to build up LBL films rapidly.

Smoothing of fast assembled layer-by-layer films by adjusting assembly conditions

“…The results are consistent with those previously reported of the films by the fast LbL method, though collected a large amount of polymers during the assembly, which usually makes the films suffered from poor qualities [24] . We then wondered whether it's possible to alter the assembly conditions to achieve multilayers with smoother surfaces, while maintaining the short assembly durations used in the assembly process.…”

“…Therefore, until now, several strategies have been proposed to accelerate the LbL process to realize a rapid film construction. For example, spin-coating [16,17] , spray [18][19][20][21] , wetting-dewetting [22] , roll-to-roll [23] , agitation [24] , and spray-spin [25] LbL processes have all been proven as efficient methods to accelerate the film construction. In addition, the employment of LbL machine would liberate human labor and achieve thick LbL film in a feasible way.…”

“…However, although the mass adsorbed onto the substrate in the first several seconds was substantial, the quality of the films, including internal structure and surface morphology, was usually poorly defined. Fu et al [24] have developed an agitation-assistant LbL method, to assemble the LbL multilayers in a very fast manner and achieved well-structured films. But the agitation-assistant LbL method also has special requirements for the assembling conditions that might be difficult to meet.…”

Avidin/PSS membrane microcapsules with biotin-binding activity

“…Layer-by-layer (LbL) thin films are prepared by an alternate deposition of two kinds of polymeric materials through an electrostatic force of attraction, hydrogen bonding, and biological affinity [1][2][3][4][5][6][7][8][9]. Heretofore, many kinds of materials have been employed for this purpose, including synthetic polymers [3,4], proteins [5,6], DNA [7], and polysaccharides [8,9].…”

“…Heretofore, many kinds of materials have been employed for this purpose, including synthetic polymers [3,4], proteins [5,6], DNA [7], and polysaccharides [8,9]. The modification of the surface of LbL films is also possible to develop composite films.…”