Ahmed IraqiDr Ahmed Iraqi

Reader in Polymer Chemistry

Room: C76

Tel: +44-(0)114-22-29566

Fax: +44-(0)114-22-29436

email:

 


 

Biographical Sketch

Dr. Iraqi obtained his BSc from the University of Fes (Morocco) in 1984. This was followed by an MSc in Chemistry from University Paul Sabatier in Toulouse in 1985 and a PhD from the same institution in 1988. Until 1996 he was a Postdoctoral Research Associate at the University of St Andrews, when he became a Lecturer at Lancaster University. In 2000 he was appointed Lecturer at the University of Sheffield, where he was promoted to Senior Lecturer in 2009 and Reader in 2013.

Research Keywords

Electroactive polymers, synthesis of novel polymers and functional materials, electroluminescence, solar cells, charge transporting materials, redox-active functionalised conjugated polymers.

Teaching Keywords

Polymer Chemistry; Organometallic Chemistry

Selected Publications:

Research Interests

Research in the area of organic conjugated polymers has developed rapidly over the last few years in view of their potential applications in electronic devices. Our research objectives are toward the design, synthesis and exploitation of the unique physical properties of these materials, in the fields of light emitting diodes, sloar cells and field effect transistors. Themes of the research programme include:

Design and development of conjugated polymers for application in displays: Considerable research efforts are devoted to develop new highly fluorescent blue light emitting polymers. Such materials are required for efficient emission in the blue part of the electromagnetic spectrum and also as energy-transfer donors and hosts for lower band gap fluorophores and phosphorescent dyes in an effort to enable the use of both singlet and triplet excitons in the radiative decay process. Polyfluorenes have attracted a lot of interest in this area and great advances have been achieved with these materials, however, polyfluorenes suffer from luck of stability of blue light emission in devices which compromises their use. We are interested in developing alternative materials for application in this area. Carbazole-based polymers such as poly(vinylcarbazole) (PVK) are widely used as hole-transporting materials, as well as wide band gap hosts to various fluorophores. However, PVK is a saturated main-chain polymer and alternative main-chain conjugated polymers are required. In our group we are developing a range of 2,7-linked and 3,6-linked carbazole main-chain conjugated polymers for application in this area. Special attention is given to 2,7-linked carbazole polymers and copolymers whose physical properties can be tailored by judicious choice of either the co-monomers used in these carbazole based materials or the nature of substituents at the 3,6-positions as well as the 9-positions of carbazole repeat units.

Design and development of conjugated polymers for application in solar cells: There is at the moment a great deal of research interest in the development of new sources of renewable energy. Photovoltaic (PV) cells offer an attractive alternative in this area; however, the cost of the current technology based on single or polycrystalline silicon PV cells is the primary limiting factor for this technology. Polymer solar cells based on blends of conjugated polymer donors and molecular acceptors (often referred to as bulk heterojunction solar cells) are attracting a great deal of interest. These systems have potential technological value due to their ease of fabrication and their relatively low production costs. Efficient harvesting of solar energy requires the development of polymers with high absorption coefficients and extended absorption spectra in order to enable photocurrent generation from lower-energy photons. This in turn will require low band gap polymers that absorb at wavelengths extending in the near-IR region of the electromagnetic spectrum. Our work in this area involves the development of new low band gap conjugated polymers that are able to absorb a wider portion of solar light than established polymers used in this area like poly(3-hexylthiophene)s. We are at present developing a range of low band gap donor/acceptor carbazole based conjugated copolymers for application in this area.

Other areas of investigation involve the synthesis and characterisation of a wide range of tractable functionalised regioregular polythiophenes by post-modification of preformed precursor polymers. Structurally homogeneous precursor polymers poly(3-(omega-bromoalkyl)thiophene)s are made with full regioregular control and further functionalised by covalent binding with desired functional groups. This synthetic approach allows obtainment of tractable redox active functionalised polythiophenes that are easily characterised by conventional analytical techniques as opposed to similar materials obtained using different polymerisation methods. The physical properties of these materials (photovoltaic and electrocatalytic activity) are being investigated.

Teaching Section

Inorganic Chemistry

Undergraduate Courses Taught

  • Chemistry and the world around us (Year 1)
    This segment discusses the underlying chemical processes that allow some molecules to emit light
  • Group Theory in Chemistry (Year 2)
    This segment introduces group theory in chemistry, and applies it to the analysis of molecular orbital diagrams and to determining the stretching vibrations in simple molecules.
  • Main Group Chemistry 2 (Year 2)
    This segment expands upon and introduces more of the wonderful and varied chemistry of the main group elements.
  • New Materials (Year 4)
    This course gives an overview of the design, preparation and uses of organic conjugated polymers and oligomers in the electronics industry and focusses on the factors governing their physical properties and their structure-property relationship in electronic device applications.

Postgraduate Courses Taught

  • CHM6204A: "Smart polymers and polymeric materials A"

Tutorial & Workshop Support

  • First Year General Tutorials.
  • Second Year Inorganic Chemistry Tutorials.
  • Third Year Literature Review.

Laboratory Teaching

  • Second Year Laboratory Demonstrating
  • Third Year Laboratory Projects
  • Fourth Year Research Project.

Journal articles

Conference proceedings papers

  • Iraqi A & Wataru I (2001) Preparation of poly(9-alkylcarbazole-3,6-diyl)s via palladium catalysed cross-coupling reactions. SYNTHETIC METALS, Vol. 119(1-3) (pp 159-160)
  • Iraqi A, Clark D, Jones R & Krier A (1999) Synthesis, characterisation and study of photoluminescent properties of head to tail poly(3-pentoxythiophene), poly(3-cyclohexylthiophene) and mixed alkoxy cyclohexyl 3-substituted polythiophenes. SYNTHETIC METALS, Vol. 102(1-3) (pp 1220-1221)
  • Schmit JPN, Davidson K & Iraqi A (1999) New synthetic routes to polyacenes. SYNTHETIC METALS, Vol. 101(1-3) (pp 100-101)
  • Crayston JA, Iraqi A, Morrison JJ & Walton JC (1997) Synthesis of thiophene substituted ruthenium and rhenium bipyridyl complexes.. SYNTHETIC METALS, Vol. 84(1-3) (pp 441-442)
  • Iraqi A, Irvin AM, Walton JC & Crayston JA (1997) Synthesis of methacrylate and silicone polymers with pendant thiophene groups. SYNTHETIC METALS, Vol. 84(1-3) (pp 377-378)
  • Iraqi A, Mlynski A, Heard A, Walton JC & Crayston JA (1997) Functionalization of poly(p-phenylenevinylene) polymers with pendant nitroxide groups. SYNTHETIC METALS, Vol. 84(1-3) (pp 333-334)
  • CRAYSTON JA, IRAQI A, MALLON P, WALTON JC & TUNSTALL DP (1993) POLYRADICALS - SYNTHETIC STRATEGIES AND CHARACTERIZATION. SYNTHETIC METALS, Vol. 55(2-3) (pp 867-872)
  • CRAYSTON JA, IRAQI A, MALLON P, WALTON JC & TUNSTALL DP (1993) POLYRADICALS - SYNTHETIC STRATEGIES AND CHARACTERIZATION. MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY SECTION A-MOLECULAR CRYSTALS AND LIQUID CRYSTALS, Vol. 234 (pp 771-775)

Patents

  • Iraqi A & Wataru I () Manufacture of 2,7-disubstituted carbazoles, their oligomers or polymers and use in electronic devices as semiconductor films.. Brit. UK Pat. Appl. (2003), GB 2383036 A 20030618 Appl. 01 Jan 1970.