Loading...
Search for: photochromism
0.188 seconds

    Synthesis of Light and pH Sensitive Gel with Nanophotochromic Cross-links and Investigation of its Applicability in Chemical Sensors

    , M.Sc. Thesis Sharif University of Technology Taheri, Shima (Author) ; Pourjavadi, Ali (Supervisor)
    Abstract
    Photochromism is defined as a reversible transformation of a chemical species between two forms having different absorption spectra induced in one or both directions by photoirradiation. Among various organic photochromic compounds, including spiropyrans, azobenzenes, spirooxazines, dyarylethenes and fulgides, spiropyranes have been attracted more attention due to their more sensitivity towards photo, pH, heat, pressure and solvent polarity. UV irradiation of spiropyrans, breaks the C-O bond of pyran ring and makes cis-trans isomers. Therefore, closed structure of the molecule, named as spiro (SP), is converting into the flattered and conjugated merocyanine (MC). Mc is photochromism, polar... 

    Synthesis and Characterization of Smart Silica Nanocomposites via Reversible Addition−Fragmentation Chain-Transfer (RAFT)Polymerization

    , M.Sc. Thesis Sharif University of Technology Rahemipoor, Sahand (Author) ; Pourjavadi, Ali (Supervisor)
    Abstract
    Photochromism is defined as a reversible transformation of a chemical species between two forms having different absorption spectra induced in one or both directions by photoirradiation. Numerous photochromic molecules were investigated such as spiropyrans (SP), spirooxazines (SO), fulgides, diarylethenes, and azobenzenes. Recently, spirooxazines have been attracted more attention due to their more sensitivity towards photo, pH, heat, pressure, solvent polarity, and high fatigue resistance. Spirooxazine moieties are one of the most popular photochromic groups that can be transformed from colorless closed ring form (SO from) to blue color open ring form by UV irradiation that so-called;... 

    Synthesis and Investigation of the Properties of Chromic Stimuli Responsive Polymers Based on Organic Compounds

    , Ph.D. Dissertation Sharif University of Technology Pourbadiei, Behzad (Author) ; Pourjavadi, Ali (Supervisor)
    Abstract
    The main goal of this study is to prepare and investigate stimuli responsive structures that respond to the light and other environmental triggers. Also, investigating their applications in biological fields such as: drug delivery and tissue engineering, in addition to the application of these materials in the field of chemical sensors that show color change with changes in solvent, electric field and metal ions. In the matter of drug delivery, guest-host interactions were used to release anticancer drugs, in such a way that with ultraviolet light irradiation and simultaneously with the formation of the cis isomer, the connections between azobenzene groups and cyclodextrin rings are...