Three novel photoinitiators, namely (2,2′-bithiophen-5-yl)(4-(N,N′dimethylaminophenyl)ketone, 5,10-dimethoxybenzo[j]fluoranthene and 6,6′-(((1E,1′E)-(2,5-bis(octyloxy)-1,4-phenylene)bis(ethene-2,1-diyl))bis(4,1-phenylene))bis(1,3,5-triazine-2,4-diamine) applicable to different near UV or visible LEDs (385 nm, 395 nm, 405 nm or cold white LED) have been developed. When incorporated into multicomponent photoinitiating systems PISs (in the presence of iodonium salt (and optionally N-vinyl carbazole) or amine/alkyl halide couples), they exhibit quite excellent photoinitiating abilities for the cationic polymerization CP of epoxides or the free radical polymerization FRP of methacrylates under air. Compared to the corresponding camphorquinone-based systems, the newly developed photoinitiating systems display noticeably higher polymerization efficiencies under air (epoxide conversions = 31−55% vs ∼0%, halogen lamp exposure; methacrylate conversion = 56−66% vs 0−8%, LED irradiation). These systems are very interesting to overcome the oxygen inhibition. The photochemical mechanisms have been studied by steady state photolysis, electron spin resonance spin trapping, fluorescence, cyclic voltammetry, and laser flash photolysis techniques.

The energy performances of pure-silica LTA-type zeosil were studied by intrusion–extrusion of water and concentrated aqueous solutions of LiCl. The LTA structure is characterized by a highly symmetrical three-dimensional pore system that consists of large cages separated by eight-membered-ring openings. The LTA-type zeosil–water system exhibits a bumper behavior with an intrusion pressure of 20 MPa and an absorption energy of 3.4 J g–1. Despite the small pore openings (0.41 × 0.41 nm2), the value of the intrusion pressure is one of the lowest obtained among all zeosils studied to date. The bumper behavior of the LTA-type zeosil–water system is explained by the formation of silanol groups arising from the breaking of siloxane bridges under water intrusion as confirmed by 29Si NMR spectroscopy, Rietveld refinement, and TG data. The change of the intruded liquid from water to aqueous LiCl solutions changes the system behavior dramatically: from bumper to a combination of shock-absorber and bumper behavior. Unlike water, no formation of silanol groups is observed after intrusion of concentrated LiCl aqueous solutions. A huge increase of the intrusion pressure from water to 20 M LiCl aqueous solution (from 20 to 148 MPa) occurs. This can be explained by the change of the intruded liquid to solvated (Li+, Cl–) ions and by the necessity of distortion of the water–ion complexes to penetrate into the small eight-membered-ring openings of the LTA structure. The results obtained confirm the hypothesis already proposed that cage-type zeosils show lower intrusion pressure values than channel-type structures.