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Optical Studies of Conjugated Polymer Nanparticles Prepared by Various Emulsion Polymerisation Methods

المصدر: مجلة كلية التنمية البشرية
الناشر: جامعة أم درمان الإسلامية - كلية التنمية البشرية
المؤلف الرئيسي: Alzamanan, Seham (Author)
المجلد/العدد: ع7
محكمة: نعم
الدولة: السودان
التاريخ الميلادي: 2019
الشهر: يوليو
الصفحات: 1 - 18
رقم MD: 1253634
نوع المحتوى: بحوث ومقالات
اللغة: الإنجليزية
قواعد المعلومات: IslamicInfo, HumanIndex
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LEADER 03081nam a22002177a 4500
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041 |a eng 
044 |b السودان 
100 |a Alzamanan, Seham  |e Author  |9 668692 
245 |a Optical Studies of Conjugated Polymer Nanparticles Prepared by Various Emulsion Polymerisation Methods 
260 |b جامعة أم درمان الإسلامية - كلية التنمية البشرية  |c 2019  |g يوليو 
300 |a 1 - 18 
336 |a بحوث ومقالات  |b Article 
520 |b The Susuki-Miyaura cross coupling polymerisation approach to formation of emissive conjugated polymer nanoparticles was presented and the flexibility of the method for preparation of particles with different emission colours was demonstrated. The as-prepared nanoparticle dispersions were clear (not turbid) and the particle hydrodynamic diameters were small, < 60 nm. Zeta potentials of the particles were strongly negative, consistent with the presence of negative surface charge on the particles, possibly due to defect formation. Spectroscopic data revealed that the particle absorption/emission was characteristic of the parent polymer. Values of photoluminescence quantum yields and lifetimes of particle dispersions were determined. The estimated radiative decay rate constants were similar to those of fluorescence dyes (ca. 108 s-1) used in flow cytometry or fluorescence imaging, and higher than those of quantum dots. Photo stability studies carried out for aqueous nanoparticle dispersions indicated that some particle types exhibited mild photo brightening under continuous illumination with stability generally observed for all particles. These observations demonstrated that the particles were more stable than conventional molecular fluorophores. Single nanoparticle imaging studies confirmed that the particles were bright with good signal-to-background characteristics being observed for all particle types. Measurements of single particle photo bleaching trajectories indicated that the majority of particles exhibited largely continuous photo bleaching behavior consistent with the multichromophoric character expected for particles composed of aggregated conjugated polymer chains with comparatively large total numbers of emissive chromophores. A few particles exhibited fluorescence intermittency or emission blinking behavior during photo bleaching which was ascribed to reversible, time-varying fluctuations in the fraction of chromophores in the emitting ('on") state present within particles composed of relatively small total numbers of emissive chromophores. Single particle death numbers of ca. 
653 |a التجارب العملية  |a الكيمياء التحليلية  |a البوليمرات 
773 |4 العلوم الإنسانية ، متعددة التخصصات  |6 Humanities, Multidisciplinary  |c 011  |l 007  |m ع7  |o 1432  |s مجلة كلية التنمية البشرية  |t Journal of Faculty of Human Development  |v 000 
856 |u 1432-000-007-011.pdf 
930 |d y  |p y  |q n 
995 |a IslamicInfo 
995 |a HumanIndex 
999 |c 1253634  |d 1253634 

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