Marie DENIS, PhD student in CEISAM CORAIL team, will defend her thesis entitled “Toward the development of ultra-fast spatio-controled covalent printing” on January 08th 2021.
Cellulose is a very common material mainly used for fabrics and paper. Writing and printing processes are mainly based on the cellulose
absorption abilities. However once adsorbed on the cellulose surface, the ink can be removed through the action of organic solvents or water. This ink removal process allows counterfeit. In order to create « security papers » our team focused on the novel concept of covalent printing. , In preliminary studies, the team developed the concept of covalent printing
through the use of thiol-X reactions. These reactions allowed a good spatial control and the whiteness of the non-printed area was preserved. Unfortunately, the time required to print patterns was too long (more
than 45 minutes) for industrials applications/developments.
In this work, the use of cyclopropenone derivatives as latent photo-released strained cyclic alkynes was then developped for the covalent printing of complex patterns on cellulose paper. The process requires 8 minutes of printing at room temperature and displays a good resolution at the
micrometer scale with negligible diffusion. The same strategy is also applied in order to create an hydrophobic patterns on paper.
For reasons of hygiene and safety, the defense will take place behind closed doors