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Different Ti-Si catalysts, viz. TiO 2 supported on amorphous SiO 2 or Si-MCM-41, TiO 2 -SiO 2 xerogels, and Ti zeolites (TS-1 and Ti-beta), were compared in terms of activity and selectivity for the direct conversion of methyl lactate to lactide in the gas phase. Except for Ti-beta, all catalysts exhibit a high lactide selectivity of 88−92% at conversions below 50%. From DR UV−vis spectroscopy, it is evidenced that the catalytic activity of tetrahedral TiO 4 sites is higher than those of polymerized TiO 5 or the octahedral TiO 6 counterparts, irrespective of the catalyst structure, an analysis supported by ToF-SIMS measurements. A kinetic analysis shows that the catalytic activity is proportional to the number of vacant sites on the catalyst surface. Thus, the activity increase observed for tetrahedral TiO 4 sites may be attributed to an increased number of vacant sites (e.g., two for TiO 4 , zero for TiO 6 ). Lactide productivity thus highly benefits from an increased dispersion of Ti sites on the catalyst surface and could be increased by a factor of 2.5 (up to 10 g LD g cat −1 h −1 ) when TiO 2 is dispersed on a Si-MCM-41 support, with higher surface areas in comparison to amorphous SiO 2 gels.

Poly(ethylene glycol) (PEG) films are known to be protein‐repelling and to reduce biofilms attachment. We use a simple, easy to set up, versatile atmospheric pressure radiofrequency plasma to deposit plasma‐polymerized poly(ethylene glycol) films onto polyvinylfluoride (PVF) and gold surfaces, using liquid or gaseous tetraglyme (CH3O(CH2CH2O)4CH3) as precursor. The chemical composition of the films was studied using infrared reflection absorption spectroscopy, X‐ray photoelectron spectroscopy and secondary ions mass spectroscopy. Bovine Serum Albumin adsorption has revealed good biocompatible properties that are correlated to the surface composition.