近年來，發光材料因其從生物感測器至發光二極體（LED）裝置的廣泛應用性而備受重視；而對於LED而言，某些如結構可拉伸的新穎特性更是給與了這領域龐大的發展潛力。但因需克服放光材料較剛性部分結構的困難性，部分以混摻軟性材料於放光材料的研究於拉伸性上仍表現了不是太好的結果。
在這項研究中，我們正嘗試直接從發光材料(磷參雜碳量子點)所合成而來的本質可拉伸、具交聯性且可放光之彈性體。我們利用位於碳量子點外的羥基進一步改質成一種可用於可逆加成-斷裂鏈轉移（RAFT）聚合的鏈轉移劑（大分子RAFT劑）；而在聚合物的部分，我們使用了一種典型彈性體材料-聚異戊二烯，其也同時為天然橡膠的主要成分。在藉由RAFT接枝聚異戊二烯於磷參雜量子點外後，我們利用聚異戊二烯上的雙鍵進一步在鐵氟龍模具上進行硫交聯，然後得到可放光的塊材彈性體。其中，之於分子量18,000的P-CQD-PI彈性體，我們製造出了足以拉長至約105%拉伸程度且達到楊氏模數0.88MPA的可放光獨立塊材彈性體。這證明了於碳量子點上利用其官能基作修飾的方式是可行的，且我們也能夠以其他具相同官能基的材料來嘗試。

Recently, luminescent materials are valued more for their wide variety of applications, ranging from biochemical sensor to light-emitting devices. And for light-emitting diode (LED), some novel characteristics like structural stretchability also give this field a big potential to develop. But for the difficulty to overcome the rigid moieties of luminescent materials, some studies that blended the flexible materials with luminescent ones showed the not good results for their stretchability.
In this study, we’re attempting to make an intrinsically stretchable, cross-linkable and luminescent elastomer, synthesized directly from the luminescent material, Phosphorous-doped carbon quantum dots (P-CQD). To combine the stretchability and luminescence, we utilize the hydroxyl group which is located outside of the P-CQD to further modify it into a kind of chain transfer agent (macro raft agent) that can be used for reversible addition−fragmentation chain transfer (RAFT) polymerization. For polymer part, we use polyisoprene, a typical elastomer material which is also a major ingredient of nature rubber. After grafted polyisoprene parts outside of the P-CQD by RAFT, we take advantage of the polyisoprene’s double bonds to do further sulfur vulcanization in Teflon mold and then get the bulk elastomer which can emit the fluorescence. Moreover, for P-CQD-PI (18K in molecular weight), we definitely fabricated the luminescent free-standing bulk elastomer enough to be stretched around 105% strain and can achieve the Young’s modulus of 0.88 MPA. It proved that the method of utilizing the functional group to modify is available for carbon quantum dots and we may attempt to use other kinds of materials with the same groups to do.

(1) Adrian, A.; Alfonso, S.; Jose´ M, C.; Rosario, P.; Alfredo, S. Fluorescent conjugated polymers for chemical and biochemical sensing. Trends Anal. Chem. 2011, 30, 9, 1513–1525.
(2) Baldo, M.; Thompson, M.; Forrest, S. High-efficiency fluorescent organic light-emitting devices using a phosphorescent sensitizer. Nature 2001, 403, 750–753.
(3) Nikolay, Z. The life and times of the LED – a 100-year historys. Nat. Photonics 2007, 1, 189–192.
(4) Wang, X.; Tian, H.; Mohammad, M.; Li, C.; Wu C.; Yang, Y.; Ren, T.L. A spectrally tunable all-graphene-based flexible field-effect light-emitting device. Nat. Commun. 2015, 6, 7767.
(5) Lian, F.; Wang, C.; Wu, Q.; Yang, M.; Wang, Z.; Zhang, C. In situ synthesis of stretchable and highly stable multi-color carbon-dots/polyurethane composite films for light-emitting devices. RSC Adv. 2020, 10, 1281–1286.
(6) Liang, J.; Li, L.; Niu, X.; Yu, Z.; Pei, Q. Elastomeric polymer light-emitting devices and displays. Nat. Photonics 2013, 7, 10, 817–824.
(7) R. B. S.G.; Shan, X.; Hoang, P.T.; Li, J.; Geske, T.; Cai, L.; Pei, Q.; Wang, C.; Yu, Z. Stretchable Light‐Emitting Diodes with Organometal‐Halide‐Perovskite–Polymer Composite Emitters. Adv. Mater. 2017, 29, 23, 1607053.
(8) Sekar R.B.; Periasamy A. Fluorescence resonance energy transfer (FRET) microscopy imaging of live cell protein localizations. J. Cell Biol. 2003, 160, 5, 629–633.
(9) Li, Y.; Young D.J.; Loh, X.J. Fluorescent gels: a review of synthesis, properties, applications and challenges. Mater. Chem. Front. 2019, 3, 1489–1502.
(10) Gaponik, N.; Rogach A.L. Thiol-capped CdTenanocrystals: progress and perspectives of the related research fields. Phys. Chem. Chem. Phys.. 2010, 12, 8685–8693.
(11) Mansur, H.S. Quantum dots and nanocomposites. Wiley Interdiscip. Rev. Nanomed. Nanobiotechnol. 2010, 2, 2, 113–129.
(12) Mo, Y.; Tang, Y.; Gao, F.; Yang, J.; Zhang, Y. Synthesis of Fluorescent CdS Quantum Dots of Tunable Light Emission with a New in Situ Produced Capping Agent. Ind. Eng. Chem. Res. 2012, 51, 17, 5995–6000.
(13) Xu, X.; Ray, R.; Gu, Y.; Ploehn, H. J.; Gearheart, L.; Raker, K.; Scrivens, W. A. Electrophoretic Analysis and Purification of Fluorescent Single-Walled Carbon Nanotube Fragments. J. Am. Chem. Soc. 2004, 126, 40, 12736–12737.
(14) Sun, Y.P.; Zhou, B.; Lin, Y.; Wang, W.; Shiral Fernando, K.A.; Pathak, P.; Meziani, M.J.; Harruff, B.A.; Wang, X.; Wang, H.; Luo, P.G.; Yang, H.; Kose, M.E.; Chen, B.; Veca, L.M.; Xie, S.Y. Quantum-sized carbon dots for bright and colorful photoluminescence. J. Am. Chem. Soc. 2006, 128, 24, 7756–7757.
(15) Demchenko, A.P.; Dekaliuk, M.O. Novel fluorescent carbonic nanomaterials for sensing and imaging. Methods Appl. Fluoresc. 2013, 1, 4, 042001.
(16) Sreenath, P.R.; Singh, S.; Satyanarayana, M.S.; Das, P.; Kumar, K.D. Carbon dot – Unique reinforcing filler for polymer with special reference to physico-mechanical properties. Polymer 2017, 112, 189–200.
(17) Li, J.; Guo, H.; Wei, A.; Jiang, J.; Ji, Y.; Qiang, H.; Jiang, Y.; Zhang, H.; Liu, H. Preparation and characterization of blue-emitting carbon quantum dots and their silicone rubber composites. Mater. Res. Express 2019, 6, 4, 045310.
(18) Au-Duong, A. N.; Wu, C. C.; Li, Y. T.; Huang, Y. S.; Cai, H. Y.; Jo Hai I; Cheng, Y. H.; Hu, C. C.; Lai, J. Y.; Kuo, C. C.; Chiu, Y. C. Synthetic Concept of Intrinsically Elastic Luminescent PolyfluoreneBased Copolymers via RAFT Polymerization. Macromolecules 2020, 53, 10, 4030–4037.
(19) Chiefari, J.; Chong, Y.K.; Ercole, F.; Krstina, J.; Jeffery, J.; Le, T.P.T.; Mayadunne, R.T.A.; Meijs, G.F.; Moad, C.L.; Moad, G.; Rizzardo, E.; Thang, S.H. Living Free-Radical Polymerization by Reversible Addition-Fragmentation Chain Transfer: The RAFT Process. Macromolecules 1998, 31, 5559–5562.
(20) Jitchum, V.; Perrier, S. Living Radical Polymerization of Isoprene via the RAFT Process. Macromolecules 2007, 40, 1408–1412.
(21) Perrier, S. 50th Anniversary Perspective: RAFT Polymerization-A User Guide Macromolecules 2017, 50, 19, 7433–7447.
(22) Wanga, W.; Yua, Y.; Wanga, P.; Wanga, Q.; Lib, Y.; Yuana, J.; Fana, X. Significant Controlled graft polymerization on the surface of filter paper via enzyme-initiated RAFT polymerization. Carbohydr. Polym. 2019, 207, 239–245.
(23) Sharmaa, S.; Mehtaa, S. K.; Ibahdonb, A. O.; Kansal, S. K. Fabrication of novel carbon quantum dots modified bismuth oxide (α-Bi2O3/C-dots): Material properties and catalytic applications. J. Colloid Interface Sci. 2019, 533, 227–237.
(24) Jiang, D. D.; Levchik, G. F.; Levchik, S. V.; Dick, C.; Liggat, J. J.; Snape, C. E.; Wilkie, C. A. Thermal degradation of Cross-Linked Polyisoprene and Polychloroprene. Polym. Degrad. Stabil. 2000, 68, 75–82.
(25) Carbonaro, C. M.; Corpino, R.; Salis, M.; Mocci, F.; Thakkar S. V.; Olla, C.; Ricci, P. C. On the Emission Properties of Carbon Dots: Reviewing Data and Discussing Models. C. 2019, 5, 60.
(26) Skrabania, K.; Miasnikova, A.; B.-K., A. M.; Zehm, D.; Laschewsky, A. Examining the UV-vis absorption of RAFT chain transfer agents and their use for polymer analysis. Polym. Chem. 2011, 2, 2074.
(27) Guo, R.; Li, T.; Shi, S. Aggregation-induced emission enhancement of carbon quantum dots and applications in light emitting devices. J. Mater. Chem. C 2019, 7, 5148–5154
(28) Gan, Z.; Xu, H.; Hao, Y. Mechanism for excitation-dependent photoluminescence from graphene quantum dots and other graphene oxide derivates: consensus, debates and challenges. Nanoscale 2016, 8, 7794–7807.
(29) Reckmeier, C. J.; Schneider, J.; Susha, A. S.; Rogach, A. L. Luminescent colloidal carbon dots: optical properties and effects of doping [Invited]. Opt. Express 2016, 24, A312-A340
(30) Zhang, S.; Ocheje, M.U.; Luo, S.; Ehlenberg, D.; Appleby, B.; Weller, D.; Zhou, D.; Rondeau-Gagné, S.; Gu, X. Probing the Viscoelastic Property of Pseudo Free-Standing Conjugated Polymeric Thin Films. Macromol. Rapid Communs. 2018, 39, 14, 180092