Elaboration of Spin-Coated Cellulose-Xyloglucan Multilayered Thin Films

Abstract

In the context of developing a biomimetic model of the primary cell wall, our aim was to produce multilayered thin films composed of cellulose nanocrystals (CN) and xyloglucan (XG). We investigated the effect of XG concentrations ranging from 0.5 g/L to 10 g/L. The choice of concentration was based on rheological investigation of the XG solutions which indicated that the two lower concentrations (0.5 and 1 g/L) correspond to a semidilute regime where the polymer chains are not entangled, whereas they are entangled at the highest concentrations (5 and 10 g/L). Several processes of film preparation were tested (dipping or spin-coating, with or without a rinsing step). The film growth profiles obtained for different XG concentrations by mechanical profilometry showed that spin-coating without rinsing was the most efficient process. Results showed that at high XG concentrations (XG = 5 g/L and XG = 10 g/L) plateau values were reached after the formation of 3 or 4 bilayers, whereas growth of the multilayer structure was linear at the lower XG concentrations (XG = 0.5 g/L and XG = 1 g/L). The thickness of one CN/XG bilayer corresponded to a single layer of CN covered by a thin XG layer, despite the absence of a rinsing step between successive coatings. The importance of the XG concentration was confirmed by determining by neutron reflectivity the film architecture obtained from four XG solutions after eight successive paired coatings. The results are discussed in relation to the role of XG in the plant cell wall.

Cell wall mechanics and growth control in plants: the role of pectins revisited

“…(3) The study of the cell wall architecture and the interactions between polymers . This can be done on intact cell walls using 3D-solid state NMR (Dick-Perez et al, 2011) or on reconstructed polymer composites with a large panel of physical techniques (Cerclier et al, 2010; Valentin et al, 2010). (4) The dissection of feedback signaling pathways involved in the mechanical homeostasis of the cell wall.…”

Elaboration of multilayered thin films based on cellulose nanocrystals and cationic xylans: application to xylanase activity detection

“…The film color can be tuned by controlling the film thicknesses. When the films are in contact with the enzymes able to hydrolyze the biopolymers, a change of the color is observed due to the decrease of the layer thickness (Cerclier et al 2010 ). This method paves the way for the simple, efficient, and highly sensitive detection of enzymatic activities.…”

“…Recently, a new method was presented for the enzymatic detection based on the structural colors of biopolymer materials (Cerclier et al 2010 ). The structural colors are known from the biological assemblies such as in butterfly wings (Vukusic and Sambles 2003 ;Vukusic 2010 ), which can also be produced artificially (Schauer et al 2003 ;Cranston and Gray 2006 ;Cerclier et al 2010 ) via an appropriate structure of the synthetic materials at the nanometric scale.…”

“…The structural colors are known from the biological assemblies such as in butterfly wings (Vukusic and Sambles 2003 ;Vukusic 2010 ), which can also be produced artificially (Schauer et al 2003 ;Cranston and Gray 2006 ;Cerclier et al 2010 ) via an appropriate structure of the synthetic materials at the nanometric scale. The structural colors are due to the semireflective properties of coating materials causing interference effects.…”

“…The latter are most often synthetic (Podsiadlo et al 2007 ;Jean et al 2008 ) and thus not degradable by enzymes. The multilayered thin films fully composed of biopolymers have been seldom investigated (Jean et al 2009 ;Cerclier et al 2010Cerclier et al , 2011Qi et al 2012 ), because film growth requires attractive interactions between polymers. Nevertheless, the biopolymer approach in combination with the CN film was demonstrated to be feasible with cationic (-chitin nanofibrils (Qi et al 2012 ).…”