含Rhodamine B之白光螢光材料：製備與其應用性質研究

Rhodamine B-containing white-light fluorescent materials:preparation and their applications

許智淵(Chih-Yuan Hsu)

指導教授 ： 劉英麟

中原大學/工學院/化學工程研究所/博士(2012年)

https://doi.org/10.6840/cycu201200541

摘要

在此研究中，使用Rhodamine B（RhB）染料成功地製備出一系列白光螢光材料。第一部分是合成出螢光二氧化矽奈米球，並將其添加至高分子中，得到光致發光型高分子薄膜與奈米纖維。依照RhB分子與二氧化矽之間的相互作用力，可分為共價鍵結與物理吸附2種。在365 nm波長激發下，RhB包覆二氧化矽奈米球可放射出白光，與RhB原本所發出的黃光不同。RhB吸附二氧化矽奈米球表面則具有環境應答的能力。在溶液中，吸附型的螢光奈米球可進行脫附，在脫附的同時，發光顏色會從白光變為黃光。此外，共價鍵結型的螢光奈米球可做為高分子添加劑使用，並利用塗布法製備出光致發光型poly(methyl methacrylate)（PMMA）薄膜與電紡絲法得到螢光PMMA奈米纖維。

第二部分內容為使用紫外光驅動RhB分子聚集，形成有機螢光奈米球。在RhB分子發生聚集後，以365 nm波長激發，RhB的發光行為會從原本的黃光轉變成白光。而此種利用紫外光驅動RhB分子聚集是一種可逆的反應，也就是當停止紫外光照射時，RhB分子便會解離，回復成小分子的狀態。因此證實了紫外光驅動法可用在製備白光螢光材料上。

第三部分則是以原子轉移自由基聚合法合成具有RhB分子的兩性螢光高分子poly(poly(ethylene glycol) methacrylate)-b-poly(glycidyl methacrylate)，並以gel permeation chromatography (GPC)、Fourier transform infrared spectroscopy (FT-IR)、proton nuclear magnetic resonance spectroscopy (1H-NMR)鑑定高分子結構。所合成出的兩性螢光高分子可在有機溶劑和水中進行自組裝。在自組裝的過程中，由於RhB分子間的強烈作用力，而形成核－殼型微胞。自組裝後的高分子微胞會因為形態不同而有黃、藍、白三種不同光色，且有螢光增強現象。最後並將製備出的高分子微胞應用在細胞的標定上。

第四部分則包括合成具有白光放射性質的RhB-terminated poly(N-isopropylacrylamide)與其自組裝結構。經由溫度驅動方式可使得高分子自組裝成環狀結構，而RhB分子除具有螢光性質外，也對高分子的自組裝產生很大的影響力。另外高分子也與β-cyclodextrin（β-CD）二聚體形成超分子聚合物，同樣可在有機溶劑內形成環形結構。因此證明經由簡易的溫度驅動過程，便可成功製成高分子環形微胞。

關鍵字

白光放射 ； 螢光材料

並列摘要

Rhodamine B (RhB)-containing materials with white-light photo- luminescence (PL) were prepared in this work. In the first part, white-light PL silica nanoparticles were synthesized and used as applications of preparation of PL polymer films and nanofibers. RhB physically adsorbs or chemically bonds to silica nanoparticle (SNP) surfaces, resulting in PL SNPs. The RhB-modified SNPs exhibit white-light PL emissions under an excitation at 365 nm, which is different from the inherent yellow light emission of RhB. The SNPs with physically-adsorbed RhB show stimuli-responsive properties. In solutions, the RhB molecules which physically adsorb to SNPs release from SNPs, consequently turning the PL emission from white-light to yellow. On the other hand, the SNPs having covalently-bonded RhB molecules are effective additives for preparation of white-light PL polymer composites. Both PL poly(methyl methacrylate) (PMMA) films (from casting process) and nanofibers (from electrospinning process) showing white-light PL emission have been prepared.

In the second part of this work, RhB aggregation into nanoparticles was performed through UV-light illumination. Along with this aggre- gation, the PL behaviors (under excitation at 365 nm) of RhB also changes, from a yellow light (RhB molecules) to a white-light (RhB nanoparticles) emission. The formation of RhB nanoparticles and the changes in the PL emissions are reversible. As a result, a novel approach to generate organic fluorescent nanoparticles and to prepare white- light-emitting fluorescent materials has been demonstrated.

The third part is preparation of RhB-anchored amphiphilic poly(poly(ethylene glycol) methacrylate)-b-poly(glycidyl methacrylate) block copolymer (polyPEGMA-b-PGMA/RhB) by a sequential atom transfer radical polymerization (ATRP) and post-functionalization of RhB. The chemical structure of polyPEGMA-b-PGMA/RhB is characterized with gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FT-IR), and 1H nuclear magnetic resonance spectroscopy (1H-NMR). PolyPEGMA-b-PGMA/RhB has shown self-assembly behaviors in tetrahydrofuran (THF) and aqueous solutions. The RhB aggregation induced with the inter-molecular interaction of RhB result in the various core-shell structures of the assembled nanoparticles. The PL properties of the polyPEGMA-b-PGMA/RhB nanoparticles are structure- dependent and exhibit yellow-light, blue-light, and white-light emissions. The fluorescent organic nanoparticles of polyPEGMA-b-PGMA/RhB were used as a bio-dye for cell labelling.

In the last part of this work, polymeric toroid from homopolymer has been demonstrated. Toroids of RhB end-capped poly(N-isopropyl- acrylamide) (polyNIPAAm-RhB and RhB-polyNIPAAm-RhB) have been obtained with a temperature-driven self-assembly process. The RhB molecules at the chain ends of polyNIPAAm provide PL properties to the polymeric toroids of RhB-terminated polyNIPAAm. Otherwise, The RhB moieties of polymer chain end play a critical role in toroidal self- assembly. RhB-terminated polyNIPAAm was also used to prepare supramolecular polymers with β-cyclodextrin (β-CD) dimer. As-prepared polymeric toroids from supramolecular polymers displayed highly uniform shape and size. Nevertheless, this strategy, temperature-driven self-assembly process, opens a new window to developing toroid-shaped polymers.

並列關鍵字

Rhodamine B ； white-light-emitting ； fluorescent material

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