Elaboration of Cellulose Nanocrystal/Ge-Imogolite Nanotube Multilayered Thin Films

Abstract

Multilayered thin films combining two oppositely charged nanoparticles (NPs), i.e., cellulose nanocrystals (CNCs) and Ge-imogolites, have been successfully obtained by the layer-by-layer method. CNC/Ge-imogolite (NP/NP) film growth patterns were studied by comparing growth mode of all of the nanoparticles thin films to that of films composed of CNC or Ge-imogolites combined with polyelectrolytes (PEs), i.e., cationic poly(allylamine hydrochloride) and anionic poly-4-styrene sulfonate (NP/PE films). NP/NP and NP/PE films growth patterns were found to be different. To get a deeper understanding of the growth mode of NP/NP, impact of different parameters, such as imogolites aspect ratio, adsorption time, ionic strength, and repeated immersion/drying, was evaluated and influence of the drying step is emphasized. The aspect ratio of imogolites was identified as an important feature for the film's architecture. The short Ge-imogolites form denser films because the surface packing was more efficient.

Influence of the Al/Ge Ratio on the Structure and Self-Organization of Anisometric Imogolite Nanotubes

“…Our findings demonstrate that synthetic Ge-DWINTs can be obtained with R' ratio from 1.8 to 2.1 while preserving their unique colloidal behavior. These results could be useful for the development of novel innovative nanocomposites based-on synthetic anisometric imogolite nanotubes [26,41,62].…”

“…Some promising attempts have been reported by changing conventional heating (reflux or autoclave) with microwave irradiation, showing an increase in the length of the tubes [37,38]. A convenient and simple way to obtain highly anisometric Ge-DWINTs is to mix in one-step Ge and Al precursors in the presence of urea CO(NH 2 ) 2 ( Figure 1a) [39][40][41][42]. Ge-DWINTs obtained with this method are structurally identical to those achieved by NaOH hydrolysis [39] but the ratio between the length and the diameter of the nanotubes (aspect ratio) is large enough to allow them to form well-ordered liquid-crystalline phases [40].…”

Ultrathin Films of Cellulose: A Materials Perspective

“…Soon afterward, Podsiadlo et al introduced LbL films of CNCs and polyethyleneimine which exhibited antireflective properties due to the suitable pore size distribution within the network of exceptionally long, tunicate-based CNCs (Podsiadlo et al, 2007). Since then, LbL films incorporating CNCs have emerged at regular intervals (Jean et al, 2008, 2009; Cerclier et al, 2010; Moreau et al, 2012; Olivier et al, 2012; Dammak et al, 2013; Olszewska et al, 2013; Azzam et al, 2014, 2015, 2017; Gill et al, 2017; Martin et al, 2017; Mauroy et al, 2018).…”

Structure and Properties of Hybrid Film Fabricated by Spin-Assisted Layer-by-Layer Assembly of Sacran and Imogolite Nanotubes

“…6,7 For instance, a previous work reported that cellulose nanocrystal (CNC), which normally has a negatively charged surface, can be used to prepare LBL films with positively charged polyelectrolytes and nanoclay. 8 Similar to CNC, sacran, another natural polysaccharide with a ultrahigh molecular weight (>1.0 × 10 7 g mol −1 ), has been extensively studied since it was first extracted from the gelatinous extracellular matrix of the cyanobacterium Aphanothece sacrum. 9−11 As shown in Scheme 1a, sacran is a negatively charged biopolymer that contains hydroxyl, carboxylate, sulfate, and a small composition of amino groups, leading to a high negative surface charge.…”