Abidin Balan

Benzotriazole containing conjugated polymers for multipurpose organic electronic applications

Benzotriazole (BTz) containing polymers have recently emerged in organic electronic applications and they are increasingly attracting a great deal of attention. These polymers are reviewed from a general perspective in terms of their potential use in three main fields, electrochromics (ECs), organic solar cells (OSCs) and organic light emitting diodes (OLEDs). In order to have a better insight into the properties of these polymers, they were compared with similar polymers. Good solubility, optical and electronic properties and synthetic availability make them multipurpose materials. They combine many desired properties in polymers and their use in different device applications is examined in detail.

Donor–acceptor type random copolymers for full visible light absorption

Copolymerization towards obtaining full visible light absorption is highlighted. Randomly distributed segments of different oligomers resulted in neutral state black copolymers. Solution processability and highly transmissive gray oxidized states make copolymers great candidates to be used in low cost flexible organic electronics.

Spray processable ambipolar benzotriazole bearing electrochromic polymers with multi-colored and transmissive states

In the context of low cost flexible display device technology, requirements can be fulfilled with accessible multi-colored electrochromic polymers. Here, we report the synthesis and electrochromic properties of two spray processable, ambipolar, fluorescent and multi-color to transmissive electrochromic polymers. Polymers, PTBTPh and PTBTTh, have multi-colored oxidation states and easily accessible n-doped states, which allowed us to achieve transmissive films in a low working potential. Electrochemical and spectral results showed that both polymers are potential materials for electrochromic display devices.

Processable donor–acceptor type electrochromes switching between multicolored and highly transmissive states towards single component RGB-based display devices

Donor–acceptor (DA) type polymers, poly(2-alkyl-4-(thiophen-2-yl)-2H-benzo[1,2,3]triazole)s (PTBT-DAs), with alternating alkyl chain substitution were synthesized and characterized in terms of their electrochemical and optical properties. Spray processable polymers have multicolored states upon oxidation and showed ambipolar characteristics in which n-type doping allowed them to achieve a transparent state in a low working potential range. Reported electrochemical and spectral results showed that PTBT-DAs are great candidates for single component electrochromic display devices. In the context of low cost flexible display device technology, requirements for polymers showing multicolored and transmissive states can be fulfilled by PTBT-DAs.

Electrochemical polymerization of (2-dodecyl-4, 7-di (thiophen-2-yl)-2H-benzo[d][1,2,3] triazole): a novel matrix for biomolecule immobilization.

A recently synthesized conducting polymer [poly(2-dodecyl-4,7-di(thiophen-2-yl)-2H-benzo[d][1,2,3]triazole (PTBT)] was tested as a platform for biomolecule immobilization. After electrochemical polymerization of the monomer (TBT) on graphite electrodes, immobilization of glucose oxidase (GOx,β-D-glucose: oxygen-1-oxidoreductase, EC 1.1.3.4) was carried out. To improve the interactions between the enzyme and hydrophobic alkyl chain on the polymeric structure, GOx and isoleucine (Ile) amino acid were mixed in sodium phosphate buffer (pH 7.0) with a high ionic strength (250 × 10(-3) M). The solution is then casted on the polymer film, and the amino groups in the protein structure were crosslinked using glutaraldehyde (GA) as the bifunctional agent. Finally, the surface was covered with a perm-selective membrane. Consequently, cross-linked enzyme crystal (CLEC) like assembles with regular shapes were observed after immobilization. Microscopic techniques such as scanning electron microscopy (SEM) and fluorescence microscopy were used to monitor the surface morphologies of both the polymer and the bioactive layer. Electrochemical responses of the enzyme electrodes were measured by monitoring O(2) consumption in the presence of glucose at -0.7 V. The optimized biosensor showed a very good linearity between 0.05 and 2.5 × 10(-3) M with a 52 s response time and a detection limit (LOD) of 0.029 × 10(-3) M to glucose. Also, kinetic parameters, operational and storage stabilities were determined. K(m) and I(max) values were found as 4.6 × 10(-3) M and 2.49 µA, respectively. It was also shown that no activity was lost during operational and storage conditions. Finally, proposed system was applied for glucose biomonitoring during fermentation in yeast culture where HPLC was used as the reference method to verify the data obtained by the proposed biosensor.

Probing Force with Mechanobase‐Induced Chemiluminescence

Mechanophores capable of releasing N-heterocyclic carbene (NHC), a strong base, are combined with triggerable chemiluminescent substrates to give a novel system for mechanically induced chemiluminescence. The mechanophores are palladium bis-NHC complexes, centrally incorporated in poly(tetrahydrofuran) (pTHF). Chemiluminescence is induced from two substrates, adamantyl phenol dioxetane (APD) and a coumaranone derivative, upon sonication of dilute solutions of the polymer complex and either APD or the coumaranone. Control experiments with a low molecular weight Pd complex showed no significant activation and the molecular weight dependence of the coumaranone emission supports the mechanical origin of the activation. The development of this system is a first step towards mechanoluminescence at lower force thresholds and catalytic mechanoluminescence.

Mechanochemical Reactions Reporting and Repairing Bond Scission in Polymers

The past 10 years have seen a resurgence of interest in the field of polymer mechanochemistry. Whilst the destructive effects of mechanical force on polymer chains have been known for decades, it was only recently that researchers tapped into these forces to realize more useful chemical transformations. The current review discusses the strategic incorporation of weak covalent bonds in polymers to create materials with stress-sensing and damage-repairing properties. Firstly, the development of mechanochromism and mechanoluminescence as stress reporters is considered. The second half focuses on the net formation of covalent bonds as a response to mechanical force, via mechanocatalysis and mechanically unmasked chemical reactivity, and concludes with perspectives for the field.