Objective
The objective of this project is a search of effective bistable photochromic systems for 3D optical memory materials. Bistable photochromic compounds applicable to such devices should meet a variety of requirements, among which are high thermal stability, high quantum yields of the photocoloration, high efficiency of light absorption in the recorded point, fluorescence and high transparency outside. The required combination is achievable through the quadratic non-linearity of the two-photon absorption. Moreover, this process is compatible with a multilayered storage using a severe focusing of a single beam. Despite rather low absolute values of two-photon absorption cross sections, femtosecond light pulses with rigid focusing into the target sections can provide the process efficiency in the radiation beam focus to be comparable with one-photon radiation. Therefore, photochromic molecules should have a rather high value of the two-photon absorption section in order to reduce the needed laser beam intensity. Fluorescent read-out of the recorded data would enable non-destructiveness of the stored information. Another important demand to the photochromic substance is a high fatigue resistance.
Photochromes that would combine all the listed characteristics remain currently unknown. However, it is possible to identify classes of organic substances with physico-chemical parameters close to the above. Their structural modifications can lead to the targeted systems. We propose to prepare systematic rows of spiropyran and spirooxazine (SPO) derivatives with alkyl and alkoxy substituents of various carbon chain lengths. The purpose of the long chain being to use the hydrophobic effect to put the photochrome into a specific geometry and aggregation state in order to insure the thermal stability of the SPO-merocyanine form. Other substituents should supply the most effective combination of properties such as photocoloration quantum yields; fluorescence quantum yields of photoproduct, two-photon absorption cross sections of SPO-form and stability to photodegradation.
Extensive physico-chemical studies from the continuous to the femtosecond time scale are planned. The long time-scale monochromatic irradiation kinetic studies using continuous irradiation and in situ UV/visible detection will allow a macroscopic quantitative modelling of the photo-initiated and aggregation processes. Photochemical and photochromic properties in nano, micro and millisecond time scales will be investigated by classical and laser flash photolysis in various environment including fluid solvents, organised medium and polymers. Ultra-short time resolved experiments in the femtosecond range and luminescent detection will permit to estimate the biphotonic absorption section. The results of the kinetic, spectral and x-ray researches will be supported by a theoretical modelling on the grounds of advanced quantum chemical methods. From these results, the establishment of structure - properties relationships will be attempted.
Beyond the possible development of a new bistable molecular system for 3D memories devices, many other important results is expected. The developing field of molecular sensors, optical limiters (variable transmission), security inks, molecular switches, dye laser materials, organic solar cell, electrochromic devices could find benefit from some of our new photochromic systems. From the basic research point of view, a better understanding of the photochromic process and a better characterisation of the photochromic molecules are anticipated.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques. See: The European Science Vocabulary.
This project has not yet been classified with EuroSciVoc.
Be the first one to suggest relevant scientific fields and help us improve our classification service
You need to log in or register to use this function
Programme(s)
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Multi-annual funding programmes that define the EU’s priorities for research and innovation.
Topic(s)
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Calls for proposals are divided into topics. A topic defines a specific subject or area for which applicants can submit proposals. The description of a topic comprises its specific scope and the expected impact of the funded project.
Call for proposal
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Data not available
Procedure for inviting applicants to submit project proposals, with the aim of receiving EU funding.
Funding Scheme
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Funding scheme (or “Type of Action”) inside a programme with common features. It specifies: the scope of what is funded; the reimbursement rate; specific evaluation criteria to qualify for funding; and the use of simplified forms of costs like lump sums.
Data not available
Coordinator
31062 Toulouse
France
The total costs incurred by this organisation to participate in the project, including direct and indirect costs. This amount is a subset of the overall project budget.