Modern technology is an essential aspect of our everyday lifestyle being vitally important to lighting, mobile phones, laptops, toys etc. The majority of these gadgets concentrate on visual electronic displays as a key selling feature. Hence, industry is in constant competition to excel while delivering new consumer demands of higher colouration efficiency, faster response times, inexpensive yet robust hardware, flexible displays and with the possibility of incorporating electronics into textiles. Traditionally, inorganic small molecules were extensively used for optical displays devices such as cathode ray tubes, liquid crystal displays, light emitting diiodes [sic] and plasma screens. However, in the past decade, significant progress in polymer electrochromism has shown many organic electroactive polymers to have the potential to satisfy the above consumer demands. Electrochromic materials (EC) have the ability to undergo a reversible colour transformation switch upon electrochemical doping, such as colour bleaching transformations. Herein, this thesis discusses how organic chemistry facilitates the advantage of structurally modifying monomeric heterocyclics to fine tune materials with interesting optical and physical properties. The polymeric form of an teraryl monomer containing a 1,4-dithiin-furan illustrated superior switching performances and electrochromic properties when compared to its parent poly 3,4-ethylene dioxythiophene (PEDOT). Poly(dithienylfuran) films displayed fast switching and reversible colour transformation at high colour contrast (CE = 212 cm2 C-1 cf. 183 cm2 C_1 for PEDOT at 95% optical switch). Formerly overlooked furan materials in organic electronics was revisted here, in which a polyfuran substituted at the 2,3-positions with an S-alkylated dithiin unit, was studied.The employment of the dithiin moiety provides intrinsic additional electroactivity, as well as a functional handle for substitution with alkyl groups, enhancing the processability of the polymer. The new polymer is compared with the closely related and well-established literature compounds PEDOT and PEDTT as well-studied, highly chalcogenated polythiophenes. The electrochromism phenomenon is not only of importance for visual optical displays but also has the potential for extended application in telecommunications with electromagnetic responses into the near infra-red (NIR) region. Herein, describe a series of symmetric and asymmetric chalcogenated azomethine monomers, robustly exherting electrochemical activity within the NIR.
|Date of Award||1 Apr 2012|
- University Of Strathclyde
|Sponsors||EPSRC (Engineering and Physical Sciences Research Council)|
|Supervisor||Rein Ulijn (Supervisor) & (Supervisor)|