Institut Charles Sadron News

In 1962, Jean-Claude Wittmann started to work at the Centre de Recherche sur les Macromolécules (CRM), which would later become the Institut Charles Sadron, where the third cycle of Macromolecular Chemistry courses were held. He joined Dr. André Kovacs’ team in 1963 for his third-cycle thesis, which he defended in 1964, allowing him to be recruited as a research assistant at CNRS. He defended his state thesis (thèse d’état) in 1971, focusing on twinning in polyethylene single crystals. This initial work, masterfully analyzed, also highlighted Jean-Claude Wittmann's unique expertise, combining inventive preparation techniques with an advanced expertise in transmission electron microscopy on very delicate materials. This dual expertise would become his trademark in all his subsequent work on polymer crystallization. After his state thesis (thèse d’état), he deepened his study of organized polymer systems during a postdoctoral stay in Montreal under the supervision of Prof. St-John Manley. His work focused on eutectic systems and epitaxy in polymer-molecular system blends (poly(?-caprolactone)-trioxane). These studies would lead to the central theme of Jean-Claude Wittmann's later research: the interactions via epitaxy of semi-crystalline polymers with various substrates. His work, particularly in collaboration with Bernard Lotz, led to an understanding of the role of nucleating agents, which control and enhance the crystallinity and properties (mechanical, transparency) of semi-crystalline polymers. Another of his major discoveries was the “decoration” of a polymer single crystal by polyethylene vapors. This innovative technique revealed the orientation of chain folds in polymer single crystals, thus settling a long-standing debate in the field.

"Last but not least," during a stay in Santa Barbara with Paul Smith's team, Jean-Claude, alongside his colleague, developed an elegant method for producing ultra-oriented films of poly(tetrafluoroethylene) (PTFE), published in a landmark paper in the journal Nature (Nature, 1991, 352, 414-417). These films exhibited unique nucleating and orienting properties for a wide range of other materials. Jean-Claude Wittmann's contributions, along with his colleague Bernard Lotz, earned him international recognition in both academia (numerous European projects) and industry (collaborations with Rhône Poulenc, Milliken, and Exxon).

After a very productive early career as a researcher, Jean-Claude took on a new challenge in 1997, when he became director of the ICS for two times (1997-2005). With the help of Jean-Jacques André, he played a key role in the ICS2000 project, which involves the construction of a new building in the Cronenbourg CNRS campus and the moving from the rather isolated old Institut Charles Sadron in the Quartier des Quinze.

Jean-Claude's interests, eclectic curiosity, and desire to share his knowledge with the others went far beyond the field of polymer science. After his retirement in 2005, he dedicated more time to computing, genealogy, and plants, sharing and teaching these subjects in his village through the Seniors Club, which he revitalized with his energy.

Jean-Claude Wittmann will be remembered as a generous colleague, open to others, scientifically honest, always motivated and creative in his various roles, and an enduring example for future generations to follow.

Jean-Claude Wittmann (right) and Bernard Lotz (left) solving an epitaxially grown polymer structure.

Text written by:
M. Brinkmann, J.-M. Guenet, A. Thierry et B. Lotz