Chemical Binding of Unsaturated Fluorenes to Poly(2‐chloroxylylene) Thin Films

Abstract

A series of substituted fluorenes with vinyl groups as reactive sites were synthesized and characterized. Fluorene‐based polymers with vinyl groups as end chains and side chains functionalities were also prepared. In both cases, successful preparation of functionalized Parylene C films (modylayers) was achieved. The set of spectral methods used has allowed us to conclude that such functionalization is based on the chemical reaction of double bonds with xylylene radicals during deposition process. Parylene C films chemically modified with specially synthesized polyfluorenes showed PL quantum efficiency comparable with neat polyfluorenes.magnified image

Influence of substituents in vinyl groups on reactivity of parylene during polymerization process

“…Most recently, it was experimentally proven that during the LPCVD of parylene over unsaturated fluorenes [16] one can observe chemical functionalization of parylene films. The authors concluded that the functionalization is based on chemical reaction of double bonds with xylylene radicals during deposition process.…”

Solid on liquid deposition, a review of technological solutions

“…As experimental evidence (see Fig. 19), tetraethyl and composite from the reaction between the molecules at nucleation of PPX (dashed); special care was taken for subsequent cleaning after the PPX layer after the composite was peeled off (Soxhlet extractor [18]) in order to remove possibly attached residues from the liquid substrate; in the deep UV, the absorption of the composite is dominated by the PPX layer; the peek corresponding to the composite is at 335 nm whereas the peak of the liquid substrate is observed at 343 nm; [ [17], permission] (b) the molecule used as liquid substrate is fluorenyldistyrene (2,7-bis-(4-vinylphenyl)-9,9dihexyl-9H-fluorene). product.…”

“…The very first evidence of the creation of such a nucleation layer as chemical reaction between a PPX monomer and a liquid was experimentally brought to evidence by [17]. In this work organic compounds bearing double bond(s) in combination with fluorene fragments were used as substrate.…”

“…15b (obtained from 9,9-dioctylfluorene-2,7-bis(trimethylborate) and 4-bromostyrene oil), reacts with PPX at nucleation. In total six other molecules have been tested successfully [17].…”

Enhanced elasticity in parylene thin films by copolymerization approach

“…We wanted to pursue this goal without losing other important characteristics, including transparency, solvent resistance, barrier properties, and biocompatibility. Various methods have been developed to functionalize parylene, including the film post treatment using chemical and physical methods (such as plasma and photo-oxidation) [10][11][12], the surface functionalization by SOLID process on reactive liquids [13][14][15][16], and the synthesis and polymerization of functionalized PC [17][18][19][20][21][22][23][24]. Since we were interested in a bulk more than a surface modification, we have followed the latter approach.…”