Udom Asawapirom

Poly(3-hexyl thiophene)-b-Fullerene Functionalized Polystyrene Copolymers (P3HT-b-PSFu) as Compatibilizer in P3HT/Phenyl-C61-butyric Acid Methyl Ester (PCBM) Solar Cells

Poly(3-hexyl thiophene)-fullerene functionalized polystyrene block copolymers (P3HT-b-PSFu) with a variety of block lengths and compositions were synthesized by reacting P3HT macroinitiator with styrene and chloromethyl styrene via an atom transfer radical polymerization. After that, the prepared copolymers were reacted with C60 via an atom transfer radical addition to obtain P3HT-b-PSFu. Chemical structures and molecular weights of the products were characterized by1H-NMR, FTIR, and GPC, respectively. Next, the various P3HT-b-PSFu copolymers were added to P3HT/PCBM bulk heterojunction (BHJ) polymer solar cell. It was found that efficiency increased from 0.52% to the maximum value of 1.23%, after adding the copolymers.

Sensitivity and specificity of PS/AA-modified nanoparticles used in malaria detection

Polystyrene (PS) nanoparticle (NP) copolymerized with acrylic acid (AA) and coloured monomer, i.e. 2,3,6,7‐tetra(2,2′‐bithiophene)‐1,4,5,8‐naphthalenetetracarboxylic‐N,N′‐di(2‐methylallyl)‐bisimide (ALN8T), was synthesized via the miniemulsion polymerization. Before applying for malaria antigen detection, the blue NP was conjugated with human polyclonal malaria IgG antibody (Ab) specific to Plasmodium falciparum. For the conjugation, three methods, i.e. physical adsorption, covalent coupling and affinity binding via streptavidin (SA) and biotin interaction, were employed. The optimum ratio of Ab to NPs used in each immobilization procedure and the latex agglutination test based on the reaction between Ab conjugated NPs and malaria patient plasma were investigated. All Ab–latex conjugates provided the high sensitivity for the detection of P. falciparum malaria plasma. The highest specificity to P. falciparum was obtained from using Ab–NPs conjugated via the SA–biotin interaction.

Thermal Behavior and Photovoltaic Performance of Fullerene Grafted Dehydrochlorinated Poly(Vinyl Chloride) in Bulk Heterojunction Solar Cells

This study describes the development of an alternative conducting polymer for organic photovoltaic cell application. Chemical structure of poly(vinyl chloride) (PVC) was modified by two reactions, dehydrochlorination followed by fullerenation. The aim of this work was to explore the feasibility of using this chemically modified PVC (C60-g-DHPVC) as an electron acceptor phase in ITO/PEDOT:PSS/P3HT:acceptor/TiOx/Al bulk heterojunction (BHJ) solar cell. From the result, it was found that the power conversion efficiency of the BHJ cell employing PCBM as an electron acceptor alone increased from 0.5% to the maximum value of 1.34%, after the addition of C60-g-DHPVC. GRAPHICAL ABSTRACT

Kinetic Studies of Atom Transfer Radical Polymerisations of Styrene and Chloromethylstyrene with Poly(3-hexyl thiophene) Macroinitiator

Poly(3-hexyl thiophene)-b-poly(styrene-co-chloromethylstyrene) copolymers, to be used as a prepolymer for preparing donor-acceptor block copolymers for organic solar cells, have been synthesised by reacting P3HT macroinitiators with styrene and chloromethylstyrene via three types of atom transfer radical polymerisation (ATRP) systems, which are (1) a normal ATRP, (2) activators generated by electron transfer (AGET), and (3) a simultaneous reverse and normal initiation (SR&NI). The kinetics of these ATRP systems were studied as a function of monomers to the macroinitiator molar ratio. It was found that all of the three types of ATRP systems led to first order kinetics with respect to monomers. The highest rate constant (k) of 3.4 × 10−3 s−1 was obtained from the SR&NI ATRP system. The molecular weights of the product determined by the GPC were lower than were the theoretical values. The result was discussed in light of the chain transfer reaction to the poly(chloromethylstyrene) repeating units. Morphology of the synthesized block copolymers, examined by an atomic force microscopy (AFM), were also compared and discussed.

Heavy metal detection by electrochemical electronic tongue with poly(thiophene)-metal oxide nanoparticle composite electrodes

Rapid monitoring methods of heavy metals in water are in great demand for industrial environmental managements. This work aims to develop a heavy metal sensing device based on an electrochemical electronic tongue using a hybrid composite of metal oxide nanoparticles and conductive polymer as the working electrodes. The electrodes were prepared by drop-casting colloidal mixtures of Regioregular poly(3-hexylthiophene) (P3HT) and metal oxide nanoparticles (ZnO or TiO2) in chloroform onto a fluorine-doped tin oxide (FTO) glass. Optical microscopy measurements reveal some microstructural organization of the metal oxide-P3HT composite films on the electrodes, in comparison to a smooth P3HT film. Cyclic voltammetry (CV) measurements using bare FTO, P3HT, P3HT/ZnO and P3HT/TiO2 electrodes were performed on aqueous solutions of various metal acetates at the concentration of 0.01M. The Principal Component Analysis (PCA) was applied to the CV results to obtain the classification of the data from the various metal salt solutions. The PCA score plot exhibits a clear separation of the data groups of different heavy metals, with the highest distinction between zinc and lead. The PCA loading plot confirms that the different electrochemical nature of the various electrodes is responsible for such distinctive classification. Further work is to examine the capability of the electrochemical electronic tongues for semi-quantitative analyses of the metal salt concentration.