高分子科学系列讲座第258-262讲, University of Melbourne, Australia

文章来源:    发布时间:2017-09-28

  报告一题目: Materials for Photon Harvesting and Concentration for Photovoltaics (NO. PSLAB259-PS2017-16) 

  : Prof. Ken Ghiggino  

  报告内容:In this presentation our recent progress in developing materials to improve the performance of luminescent solar concentrators (LSCs) and light energy up-conversion will be described. LSCs consist of high concentrations of fluorescent compounds incorporated in large area planar waveguides. The concentrated luminescence at the edge of LSCs can be captured to improve solar cell performance. However problems with existing fluorophores for LSCs include fluorescence quenching due to aggregation at the high concentrations required for maximizing light absorption, and self-absorption of the emission due to the small Stokes shifts. In our laboratories concentration quenching resistant fluorophores have been developed based on a molecular insulation approach. These include extended conjugated systems based on a tetraphenylethene motif and sterically insulated perylene diimide molecules that maintain high emission quantum yields in polymer matrices at concentrations exceeding 50mM. We have also employed an energy migration and trapping approach in mixed dye fluorophore systems to minimize emission reabsorption and provide LSC devices with superior performance.  The use of polymers with appended dyes for light energy upconversion will also be described. The potential impact of these materials in future solar energy conversion technologies will be presented. 

  报告人简介:Ken Ghiggino is the Masson Professor of Chemistry at The University of Melbourne. He is a BSc (Hons) and PhD graduate of the University of New South Wales. His research group has published over 230 papers with recent research on new semiconducting materials for organic solar cells, single molecule spectroscopy, and ultrafast spectroscopy of artificial photosynthetic systems. He is a Chief Investigator in the Australian Centre for Advanced Photovoltaics (ACAP) and the ARC Centre of Excellence in Exciton Science (ACEx). He is a fellow of the Royal Australian Chemical Institute (RACI) and the Royal Society of Chemistry (RSC) and a past president of the Asian Photochemistry Association.



  报告二题目: Time-Resolved and Fluorescence Anisotropy Imaging of Organic Photovoltaic Materials (NO. PSLAB260-PS2017-17) 

  : Prof. Trevor Smith 

  报告内容:Thin films of conjugated polymers, either neat or as blends of electron donor and acceptor materials, form the basis of solar harvesting and electroluminescence-based display technologies. The techniques used to cast the film can significantly influence its photophysical behaviour, and ultimately the efficiency of the device in its given application. The morphology of the cast film can be dependent on factors such as the solvent used, the drying rate, thermal or solvent vapour annealing and other external influences such as electric fields or shear. The degree of alignment of the polymer chains can also influence the photophysics of the polymer film, particularly through mediating or inhibiting excitation energy migration.  

  We will report on the use of time-resolved fluorescence imaging and fluorescence anisotropy mapping to investigate the degree of alignment and energy migration within light-emitting conjugated polymer films cast by different techniques and as a function of solvent. Films of MEH-PPV and P3HT/PCBM were cast using an evaporative self-assembly (“snakeskin”) method and off-centre spin-coating, and the photophysical behaviour of these films is shown to depend significantly on the casting technique, the solvent used and the position within the film. 

  报告人简介:Professor Trevor Smith received his PhD degree from the University of Melbourne in 1992. He held a post-doctoral position in the laboratories of Profs. David Phillips and Garry Rumbles at Imperial College, London before returning to the University of Melbourne where he has held positions including an Ernst & Grace Matthaei Research Fellowship and an ARC QEII Research Fellowship. He is a Chief Investigator in the ARC Centre of Excellence in Exciton Science, through which the research activities of his group focusses on developing and using time-resolved laser spectroscopy and optical microscopy techniques for studying advanced materials including semiconductor nanoparticles and polymers. 


  报告三题目: The Viscosity-Radius Relationship for Semi-Dilute Polymers (NO. PSLAB261-PS2017-18) 

  : Prof. Dave Dunstan 

  报告内容:Scaling arguments have been used to determine the dependence of the viscosity,, on temperature, T and separately, the dependence of the radius, R, on temperature for semi-dilute polymer solutions. The transitive equivalence postulate is then used to predict the viscosity-radius relationship to be  . The viscosity is shown to be a power law function of the radius, and to decrease with decreasing radius. Shear thinning is thus a result of a decreasing radius with increasing shear rate as   where n is the power law exponent. The thermal expansion coefficient determines the variation in the power law exponents for different polymer systems. 

  报告人简介:Professor Dunstan obtained his Ph. D. at Melbourne University under the supervision of Professor Lee White. He then undertook Post Doctoral work at Uppsala University (Sweden), The University of California, Santa Barbara. And Princeton University. He returned to Melbourne University to take up a Senior research position and was promoted to Professor in 2008. His research interests are in polymer physics and protein biophysics. 


  报告四题目: Synthesis of Small Molecule, and Pendant Polymer Chromophores for Light Harvesting, including Triplet Up-Conversion and Singlet Fission Materials  (NO. PSLAB262-PS2017-19) 

  : Prof. Jonathan White 

  报告内容:This presentation will describe the synthesis of well-defined oligomers of phenylene vinylene (PPV) ranging from trimers up to pentamers and some of their photophysical properties. These chromophores have also been included as pendants to a polymeric scaffold attached to CdSe Quantum dots to investigate electron transfer upon excitation of the QD. Synthesis of Zn Porphrins as small molecules and as pendants attachments on a polystytrene backbone for applications in Triplet up-conversion will also be described. Early results on the synthesis of Diketopyrrolopyrrole derivatives (DPP) for singlet up-conversion will be described. 

  报告人简介:Professor Jonathan White received his PhD degree from Canterbury University New Zealand under the supervision of Professor Michael Hartshorn in 1985. He then joined the University of Bristol working with Roger Alder and Guy Orpen. After a further appointments at the Australian National University he was appointed at The University of Melbourne where he is now Professor. His research activities range from X-ray crystallography and Structural Organic Chemistry, Radiopharmaceuticals, including radioprotectors and 18-F PET imaging agents to synthesis of photochromic materials to better understand the principles underlying the interaction of these materials with light. 

  单   : University of Melbourne, Australia 

  报告时间: 20170929日(星期五) 下午13:30开始 

  报告地点: 主楼四楼学术厅(410房间)