Layer‐by‐layer films based on charge transfer interaction of ϕ‐conjugated poly(dithiafulvene) and incorporation of gold nanoparticles into the films

Abstract

Layer-by-layer (LBL) self-assembled ultrathin films were prepared via consecutively alternating immersion of substrates into solutions of electron donor, poly(dithiafulvene) (PDF), and electron acceptor, poly(hexanyl viologen) (6-VP). The charge transfer (CT) interaction formed at solid-liquid interfaces between the backbones of the electron acceptor and donor polymers was the driving force of the alternative deposition. The sandwich heterostructure of the LBL film led to electrical anisotropy in the directions parallel and perpendicular to the film surfaces. Incorporation of gold nanoparticles into the LBL films was investigated by reducing gold ions with the PDF layers already deposited on the film surfaces, or depositing PDFprotected gold colloidal solution as the electron donor layers directly. The influence of the gold nanoparticles on the electrical anisotropy of the LBL films was also illustrated in this research.

Molecular Interactions Driving the Layer-by-Layer Assembly of Multilayers

“…The authors investigated the incorporation of AuNPs into those LbL films either by reducing the gold ions with the previous deposited PDF layers or by directly depositing PDF-stabilized AuNPs as the electron-donor layers. 593 Both inclusion methods have ensured good compatibility of the AuNPs with the LbL films and are applicable to other metal or semiconducting nanoparticles. Recently, Zhang and co-workers 594 reported the generation of CT LbL films assembled from a two-component supramolecular amphiphile (8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt−1′,1″-(butane-1,4-diyl)-bis-(1-methyl-4,4′-bipyridine-1,1′-diium)dibromide diiodide (HPTS−diMV)) and diazoresins (photosensitive agent, DAR) followed by stabilization of their structure by photochemical cross-linking (see Figure 27).…”

Surface-Engineered Fire Protective Coatings for Fabrics through Sol-Gel and Layer-by-Layer Methods: An Overview

“…As an example, diethylphosphatoethyltriethoxysilane (DPTES) was utilized as a precursor for synthesizing a hybrid phosphorus-silicon organic-inorganic coating: more specifically, a multistep sol-gel process was exploited for obtaining hybrid phosphorus-doped silica architectures (from one to six layers) coated on cotton [45]. The obtained coatings were responsible for a decrease (up to´43%) of the burning time of the treated fabrics with respect to untreated counterparts, as indicated by the flameout values (66,62, and 80 vs. 116 s, respectively, for one, three, and six layers vs. untreated cotton) measured in cone calorimetry tests. In addition, notwithstanding a decrease of TTI (10 vs. 18 s, for six layers and untreated cotton, respectively), the sol-gel-derived coatings were able to limit the formation of volatile species, as indicated by the TSR values (20,15, and 6 vs. 26 m 2 /m 2 , respectively, for one, three, and six layers vs. untreated cotton).…”

“…Thus, it can be considered as a step-by-step coating build-up mainly based on electrostatic forces, although different interactions (e.g., hydrogen bonds [62,63], covalent bonds [64,65], donor-acceptor interactions [66], stereo-complex formation [67,68], etc.) can also be employed.…”

Eco –friendly flame retardant via self assembly coating

“…These coatings described by Layer by Layer (LbL) which exhibit hybrid organic and inorganic composition or complete inorganic, can be made by using different approaches [9]. LbL was first described in 1966 [10][11][12][13][14]. The LbL is an encouraging technique by which an adsorption technique of nano-particles is created [10].…”