Download or read book Investigating the Photophysics of Conjugated Polymer Chemosensors in the Solid State written by Justin Che and published by . This book was released on 2009 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigating the Photophysics of Fluorescent Conjugated Polymer Chemosensors in the Solid State written by Sherryllene Sandrena Pinnock and published by . This book was released on 2011 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigating the Photophysics of Fluorescent Conjugated Metallopolymer Chemosensors for Iron in Solid State Thin Films written by Sarah Dill and published by . This book was released on 2013 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigating the Photochemistry and Photophysics of Conjugated Polymers by Single Molecule Spectroscopy written by Dehong Hu and published by . This book was released on 1999 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design Synthesis and Photophysics of Fluorescence turn on Conjugated Polymer Chemosensors written by Li-juan Fan and published by . This book was released on 2006 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Stabilizaiton and Photophysics of Unconventional Conjugated Polymers written by Kara Martin and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Conjugated polymers offer a unique opportunity to develop high performing, flexible, lightweight, and large area electronic devices. With advances in conjugated polymer understanding and synthesis, the use of polymers as active layer materials in electronic applications, rather than just substrate materials, has become more promising. However, defects in morphological stability, as well as imperfect electronic understanding, are still present, limiting the use of these materials in commercializable electronics. Fundamental understanding of structure-property relationships can allow for facile synthetic solutions to major drawbacks of conjugated polymer integration in standard device architectures. Chapter 1 presents background research on the history of conjugated polymer development and the electronic device architectures these materials are typically incorporated in. Chapter 2 presents the use of thiol-ene chemistry to stabilize poly(3-alkylthiophene) films through a grafting-to procedure. This offers a simple way to produce highly oriented, insoluble, semi-conducting films through facile synthetic tuning of the polymers end-groups and side chains. In Chapter 3, the photophysics of carborane containing poly(dihexylfluorene) polymers is discussed. These unique class of materials experience drastic solvatochromism making them highly coveted for simple sensing applications. Through extensive spectroscopic investigations, a complete understanding of the excited-state dynamics is presented. Chapter 4 extends on Chapter 3 by demonstrating a straightforward method to synthesize carborane containing poly(dihexylfluorene)s with emissive properties that change with fluorene conjugation length, allowing for emission color tuning of the polymer solid and solution states. Lastly, Chapter 5 presents the synthesis of novel poly(bisthienyl carborane) and poly(bisthienyl carborane-alt-thiophene) is presented. This is the first example of a soluble conjugated polymer implementing a strong donor aromatic group and a strong acceptor carborane junction in the repeat unit. The fascinating excited-state characteristics are determined through femtosecond and nanosecond spectroscopy, showing the polymer can promote triplet formation on the carborane unit, making it useful for triplet sensitization applications. The work presented in this thesis shows that straightforward synthetic techniques can be used to highly affect the properties of common conjugated polymers, making them more robust or beneficial for electronic applications. Side-chain and backbone engineering is a necessary technique for furthering the development of useful and applicable "plastic" electronics.
Download or read book Design Synthesis and Photophysics of Dipyrrolequinoxaline Receptor Loaded Fluorescent Conjugated Polymer Chemosensors written by Catherine N. Malele and published by . This book was released on 2009 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Synthesis and Photophysical Analysis of Structurally Modified Fluorescent Conjugated Polymer Chemosensor Backbones written by Zachary Louis Logozio and published by . This book was released on 2010 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemistry and Photophysics of Polymeric Materials written by Norman S. Allen and published by John Wiley & Sons. This book was released on 2010-03-18 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents the state of the technology, from fundamentals to new materials and applications Today's electronic devices, computers, solar cells, printing, imaging, copying, and recording technology, to name a few, all owe a debt to our growing understanding of the photophysics and photochemistry of polymeric materials. This book draws together, analyzes, and presents our current understanding of polymer photochemistry and photophysics. In addition to exploring materials, mechanisms, processes, and properties, the handbook also highlights the latest applications in the field and points to new developments on the horizon. Photochemistry and Photophysics of Polymer Materials is divided into seventeen chapters, including: Optical and luminescent properties and applications of metal complex-based polymers Photoinitiators for free radical polymerization reactions Photovoltaic polymer materials Photoimaging and lithographic processes in polymers Photostabilization of polymer materials Photodegradation processes in polymeric materials Each chapter, written by one or more leading experts and pioneers in the field, incorporates all the latest findings and developments as well as the authors' own personal insights and perspectives. References guide readers to the literature for further investigation of individual topics. Together, the contributions represent a series of major developments in the polymer world in which light and its energy have been put to valuable use. Not only does this reference capture our current state of knowledge, but it also provides the foundation for new research and the development of new materials and new applications.
Download or read book Investigation of Photophysical and Photochemical Processes in Conjugated Polymer Nanoparticles by Single Particle and Ensemble Spectroscopy written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigation of photophysical and photochemical processes in conjugated polymer nanoparticles by single particle and ensemble spectroscopy.
Download or read book Long lived Photophysics of Conjugated Polymers written by Christine Marie Liberatore Cuppoletti and published by . This book was released on 2002 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photophysics and Photochemistry of Conjugated Polymer Nanoparticles written by Scott N. Clafton and published by . This book was released on 2014 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt: Nanoparticles prepared by the reprecipitation of conjugated polymers are an exciting development in the field of biological imaging and fluorescence sensing. The colloidal stability of these hydrophobic polymers in aqueous suspension was found to originate from the surface charge density of ~15 mC/m2, which is in part attributed to negatively charged functional groups produced by polymer oxidation. The suitability of these nanoparticles in traditional conjugated polymer applications, such as polymer photovoltaics, was also investigated using femtosecond fluorescence upconversion and transient absorption spectroscopies. Polarisation resolved studies of energy transfer in highly compact nanoparticles and extended polymer conformations showed the nanoparticles exclusively undergo intermolecular energy transfer. These observations were supported by energy transfer simulations on polymer structures obtained from coarse-grained molecular dynamics simulations. Next, the recombination of polarons in composite rr-P3HT/PCBM nanoparticles, dominated by geminate recombination below 10 wt% PCBM, was demonstrated using a one dimensional diffusion model. This model also yielded the P3HT domain size of ~5 nm, which confirms these nanoparticles can serve as a model system for probing charge generation and recombination processes in device-like environments. Finally, the power dependent exciton decay in highly ordered nanowires yielded an exciton diffusion length of 11 ± 3 nm, which is toward the upper limit of diffusion lengths reported for annealed P3HT films. This data indicates the gentle solution based crystallisation of nanowires is a promising route for enhancing the performance of bulk heterojunction devices.
Download or read book Excited State Properties of Organic and Organometallic Oligomers Polymers and Materials and Their Solid State Applications written by Randi Sue Price and published by . This book was released on 2013 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this research is to study the excited state dynamics of conjugated molecules, oligomers and polymers in the solid state and compare these photophysical properties to those found in solution. To study the triplet excited state dynamics of films a new nanosecond transient absorption instrumentation was developed. This instrument can detect transient absorption with ... A as low as of 10-3. Using this newly available instrumentation, it is possible to measure the triplet excited state dynamics so as to gain insight into several solid-state applications of photoactive molecules, oligomers, and polymers. A series of p-phenylene vinylene platinum acetylide complexes are studied for optical power limiting applications, and they are incorporated into poly(methyl methacrylate) (PMMA) monoliths. The photophysical properties of the monoliths and Triplet-triplet annihilation in conjugated co-polymers containing phenylene and p-phenylene vinylene platinum acetylide units is observed and compared against representative "monomer" complexes using transient absorption spectroscopy as a function of increasing laser fluence of the excitation pulse. The interaction between conjugated polymer, MEH-PPV, and a trimeric perfluoro-ortho-phenylene mercury complex, Hg3 is investigated in solution and in films. Finally cationic oligomers are intercalated into a clay host, and the photophysical properties of the clay-oligomer hybrid are investigated in disperse solutions and in films.
Download or read book An Investigation of the Photophysical Properties of Some Conjugated Polymers written by D. A. Ross and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Enhanced Photophysics of Conjugated Polymers written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The addition of oppositely charged surfactant to fluorescent ionic conjugated polymer forms a polymer-surfactant complex that exhibits at least one improved photophysical property. The conjugated polymer is a fluorescent ionic polymer that typically has at least one ionic side chain or moiety that interacts with the specific surfactant selected. The photophysical property improvements may include increased fluorescence quantum efficiency, wavelength-independent emission and absorption spectra, and more stable fluorescence decay kinetics. The complexation typically occurs in a solution of a polar solvent in which the polymer and surfactant are soluble, but it may also occur in a mixture of solvents. The solution is commonly prepared with a surfactant molecule:monomer repeat unit of polymer ratio ranging from about 1:100 to about 1:1. A polymer-surfactant complex precipitate is formed as the ratio approaches 1:1. This precipitate is recoverable and usable in many forms.
Download or read book Investigation of the Photophysical Properties of conjugated pi conjugated Polymers written by Richard Hildner and published by . This book was released on 2008 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Resolving Puzzles in Conjugated Polymer Photophysics written by Chakraborty Rajarshi and published by . This book was released on 2017 with total page 129 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Conjugated polymers are active candidates of research for their potential applications in organic electronic devices. This thesis contains experimental results of the photophysical behaviour of Poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) in the nanoseconds timescale. It is generally accepted that quantum yield of films are less than their solution counterparts and has a non-exponential "temporal tail" in the decay dynamics. This thesis reports the spectroscopy, excitation wavelength dependence, temperature dependence and electric field quenching of the temporal tail of the photoluminescence in MEH-PPV on a nanosecond timescale. We try to understand if a correlation exists between the "temporal tail" and quantum yield in films. We conclude that the tail represents emission from H-like aggregated regions in the polymer. Using a simple model of the photophysics, we estimate the formation yield of the aggregates responsible for the tail emission and conclude that they cannot account for the large reduction in fluorescence observed in densely packed films relative to that in solution. If recombination of injected charges in an OLED follows quantum spin statistics and all recombination forms the lowest excited states in a spin manifold, then the ratio of formed singlet to triplet exciton would be 1:3 setting an efficiency limit of 25% to the EL emission. However, in conjugated polymers, various studies have reported the formation ratio of singlet to triplet excitons to be greater than 1:3. These results have ambiguity due to issues of magnetoresistance, TTA, charge trapping, outcoupling etc. We try to reexamine the singlet-triplet branching ratio in Poly[(9,9-di-n-octylfluorenyl-2,7-diyl)-alt- (benzo [2,1,3] thiadiazol-4,8-diyl) (F8BT) along with MEH-PPV with the hope of circumventing these problems. This approach involves simultaneous detection of singlet and triplet state luminescence and then estimate the recombination branching ratios directly from the change in singlet and triplet signals produced by applying magnetic fields. The role of PP in F8BT films are addressed based on studying the effect of external magnetic field on the DF and triplet signals of gold nanoparticle doped films. This work is unique and important because it includes a delay dependent magnetic field effect study of the DF suggesting that spin randomization of charge pairs is a fast process that occurs on the several hundred nanoseconds time scale. The magnetic field effect on the fluorescence persists to tens of microseconds and we argue that this apparent inconsistency implies the existence of an intermediate state in the recombination process that has implications for measurements and theoretical treatments of the singlet recombination fraction in electroluminescent conjugated polymers."--Pages ix-x.
