Simultaneous measurement of fluorescence, conversion and physical/mechanical properties for monitoring bulk and localized photopolymerization reactions in heterogeneous systems

Abstract

An FT-NIR spectrometer, rheometer and fluorescence spectrophotometer were coupled for the real-time monitoring of polymerization reactions, allowing the simultaneous tracking of polymerization kinetics, storage modulus as well as fluorescence. In this study, a methacrylate functionalized dansyl chromophore (DANSMA) was synthesized and two different nanogels were made from urethane dimethacrylate and isobornyl methacrylate. Two series of resin formulations were prepared using the DANSMA probe, ethoxylated bisphenol A dimethacrylate as the matrix monomer, Irgacure® 651 as the initiator and the dispersed, monomer-swollen nanogels to give clear UV-curable resins. Placement of the fluorescent probe either throughout the resin or linked into the nanogel before its dispersion in the matrix provides a tool to study how the nanogel structure affects local network development by means of fluorescence from the DANSMA probe. We demonstrate the potential of this new technique using a composite as the two phase system (resin and polymerizable nanogel) including a dansyl derivative as a polymerizable probe to follow the reactions that are taking places in both phases.

Applicability of 1,6-Diphenylquinolin-2-one Derivatives as Fluorescent Sensors for Monitoring the Progress of Photopolymerisation Processes and as Photosensitisers for Bimolecular Photoinitiating Systems

“…An unquestionable advantage of using this parameter is the ability to measure the ratio intensity accurately, as was confirmed in subsequent studies [32]. This can be attributed to the fact that when the lengths of the waves arranged on both sides of the fluorescence spectrum maximum are appropriately selected, the fluorescence intensity ratio (R) is a linear function of the degree of conversion of monomer function groups [33,34,35].…”

Application of an addition–fragmentation-chain transfer monomer in di(meth)acrylate network formation to reduce polymerization shrinkage stress

“…This crossover point can be taken to estimate the gel point conversion of the sample where an infinite polymer network develops in the material. The rheometer was modified to function as a photorheometer, allowing for polymerization of the sample with light while simultaneously using NIR fiber optics to monitor real time conversion 42 . The rheometer was used in a parallel plate configuration with samples being placed between two quartz plates (20 mm diameter, sample thickness = 0.5 mm).…”

Surface-Charge-Switchable and Size-Transformable Thermosensitive Nanocomposites for Chemo-Photothermal Eradication of Bacterial Biofilms in Vitro and in Vivo

“…As shown in Figure S5, DANSMA was synthesized according to Stansbury's method. 52 Specifically, 2-aminoethyl methacrylate hydrochloride (0.56 g, 3.40 mmol) was added into a 100 mL round-bottom flask containing ethyl acetate (EA, 30 mL), and then triethylamine (2.2 mL, 15.10 mmol) was added to remove hydrochloric acid. After stirring at room temperature for 1 h, the white precipitate was gradually generated and removed by filtration.…”