1
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Zhang Q, Luo G, Hu R, Yang G, Chen J, Yu T, Zeng Y, Li Y. Crystalline hydrogen-bonded organic framework for air-tolerant triplet-triplet annihilation upconversion. Chem Commun (Camb) 2024; 60:4475-4478. [PMID: 38563956 DOI: 10.1039/d4cc00742e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
A hydrogen-bonded organic framework (HOF) consisting of a 9,10-diphenylanthracene carboxylic derivative, DPACOOH, was developed for solid state triplet-triplet annihilation upconversion (TTA-UC). The HOF sample shows a 70% increase in upconversion quantum yield and a lower threshold value of 126.0 mW cm-2 compared to those of the disordered powder sample, due to a 43% longer triplet diffusion length in HOF than that in the powder sample.
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Affiliation(s)
- Qiaoyu Zhang
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Guiwen Luo
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Rui Hu
- Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
| | - Guoqiang Yang
- Key Laboratory of Photochemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Jinping Chen
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Tianjun Yu
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
| | - Yi Zeng
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yi Li
- Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China
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2
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O’Dea C, Isokuortti J, Comer EE, Roberts ST, Page ZA. Triplet Upconversion under Ambient Conditions Enables Digital Light Processing 3D Printing. ACS CENTRAL SCIENCE 2024; 10:272-282. [PMID: 38435512 PMCID: PMC10906251 DOI: 10.1021/acscentsci.3c01263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 03/05/2024]
Abstract
The rapid photochemical conversion of materials from liquid to solid (i.e., curing) has enabled the fabrication of modern plastics used in microelectronics, dentistry, and medicine. However, industrialized photocurables remain restricted to unimolecular bond homolysis reactions (Type I photoinitiations) that are driven by high-energy UV light. This narrow mechanistic scope both challenges the production of high-resolution objects and restricts the materials that can be produced using emergent manufacturing technologies (e.g., 3D printing). Herein we develop a photosystem based on triplet-triplet annihilation upconversion (TTA-UC) that efficiently drives a Type I photocuring process using green light at low power density (<10 mW/cm2) and in the presence of ambient oxygen. This system also exhibits a superlinear dependence of its cure depth on the light exposure intensity, which enhances spatial resolution. This enables for the first-time integration of TTA-UC in an inexpensive, rapid, and high-resolution manufacturing process, digital light processing (DLP) 3D printing. Moreover, relative to traditional Type I and Type II (photoredox) strategies, the present TTA-UC photoinitiation method results in improved cure depth confinement and resin shelf stability. This report provides a user-friendly avenue to utilize TTA-UC in ambient photochemical processes and paves the way toward fabrication of next-generation plastics with improved geometric precision and functionality.
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Affiliation(s)
- Connor
J. O’Dea
- Department of Chemistry, The
University of Texas at Austin, Austin, Texas 78712 ,United States
| | - Jussi Isokuortti
- Department of Chemistry, The
University of Texas at Austin, Austin, Texas 78712 ,United States
| | - Emma E. Comer
- Department of Chemistry, The
University of Texas at Austin, Austin, Texas 78712 ,United States
| | - Sean T. Roberts
- Department of Chemistry, The
University of Texas at Austin, Austin, Texas 78712 ,United States
| | - Zachariah A. Page
- Department of Chemistry, The
University of Texas at Austin, Austin, Texas 78712 ,United States
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3
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Zhou Q, Wirtz BM, Schloemer TH, Burroughs MC, Hu M, Narayanan P, Lyu J, Gallegos AO, Layton C, Mai DJ, Congreve DN. Spatially Controlled UV Light Generation at Depth using Upconversion Micelles. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2301563. [PMID: 37548335 DOI: 10.1002/adma.202301563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 07/26/2023] [Indexed: 08/08/2023]
Abstract
UV light can trigger a plethora of useful photochemical reactions for diverse applications, including photocatalysis, photopolymerization, and drug delivery. These applications typically require penetration of high-energy photons deep into materials, yet delivering these photons beyond the surface is extremely challenging due to absorption and scattering effects. Triplet-triplet annihilation upconversion (TTA-UC) shows great promise to circumvent this issue by generating high-energy photons from incident lower-energy photons. However, molecules that facilitate TTA-UC usually have poor water solubility, limiting their deployment in aqueous environments. To address this challenge, a nanoencapsulation method is leveraged to fabricate water-compatible UC micelles, enabling on-demand UV photon generation deep into materials. Two iridium-based complexes are presented for use as TTA-UC sensitizers with increased solubilities that facilitate the formation of highly emissive UV-upconverting micelles. Furthermore, this encapsulation method is shown to be generalizable to nineteen UV-emitting UC systems, accessing a range of upconverted UV emission profiles with wavelengths as low as 350 nm. As a proof-of-principle demonstration of precision photochemistry at depth, UV-emitting UC micelles are used to photolyze a fluorophore at a focal point nearly a centimeter beyond the surface, revealing opportunities for spatially controlled manipulation deep into UV-responsive materials.
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Affiliation(s)
- Qi Zhou
- Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Brendan M Wirtz
- Department of Chemical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Tracy H Schloemer
- Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Michael C Burroughs
- Department of Chemical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Manchen Hu
- Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Pournima Narayanan
- Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA
- Department of Chemistry, Stanford University, Stanford, 94305, CA, USA
| | - Junrui Lyu
- Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Arynn O Gallegos
- Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Colette Layton
- Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Danielle J Mai
- Department of Chemical Engineering, Stanford University, Stanford, 94305, CA, USA
| | - Daniel N Congreve
- Department of Electrical Engineering, Stanford University, Stanford, 94305, CA, USA
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4
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Schloemer TH, Sanders SN, Narayanan P, Zhou Q, Hu M, Congreve DN. Controlling the durability and optical properties of triplet-triplet annihilation upconversion nanocapsules. NANOSCALE 2023; 15:6880-6889. [PMID: 37000152 DOI: 10.1039/d3nr00067b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Deep penetration of high energy photons by direct irradiation is often not feasible due to absorption and scattering losses, which are generally exacerbated as photon energy increases. Precise generation of high energy photons beneath a surface can circumvent these losses and significantly transform optically controlled processes like photocatalysis or 3D printing. Using triplet-triplet annihilation upconversion (TTA-UC), a nonlinear process, we can locally convert two transmissive low energy photons into one high energy photon. We recently demonstrated the use of nanocapsules for high energy photon generation at depth, with durability within a variety of chemical environments due to the formation of a dense, protective silica shell that prevents content leakage and nanocapsule aggregation. Here, we show the importance of the feed concentrations of the tetraethylorthosilicate (TEOS) monomer and the methoxy poly(ethyleneglycol) silane (PEG-silane) ligand used to synthesize these nanocapsules using spectroscopic and microscopy characterizations. At optimal TEOS and PEG-silane concentrations, minimal nanocapsule leakage can be obtained which maximizes UC photoluminescence. We also spectroscopically study the origin of inefficient upconversion from UCNCs made using sub-optimal conditions to probe how TEOS and PEG-silane concentrations impact the equilibrium between productive shell growth and side product formation, like amorphous silica. Furthermore, this optimized fabrication protocol can be applied to encapsulate multiple TTA-UC systems and other emissive dyes to generate anti-Stokes or Stokes shifted emission, respectively. These results show that simple synthetic controls can be tuned to obtain robust, well-dispersed, bright upconverting nanoparticles for subsequent integration in optically controlled technologies.
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Affiliation(s)
- Tracy H Schloemer
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
| | - Samuel N Sanders
- Rowland Institute at Harvard University, Cambridge, MA 02142, USA
| | - Pournima Narayanan
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Qi Zhou
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
| | - Manchen Hu
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
| | - Daniel N Congreve
- Department of Electrical Engineering, Stanford University, Stanford, CA 94305, USA.
- Rowland Institute at Harvard University, Cambridge, MA 02142, USA
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5
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Schloemer T, Narayanan P, Zhou Q, Belliveau E, Seitz M, Congreve DN. Nanoengineering Triplet-Triplet Annihilation Upconversion: From Materials to Real-World Applications. ACS NANO 2023; 17:3259-3288. [PMID: 36800310 DOI: 10.1021/acsnano.3c00543] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Using light to control matter has captured the imagination of scientists for generations, as there is an abundance of photons at our disposal. Yet delivering photons beyond the surface to many photoresponsive systems has proven challenging, particularly at scale, due to light attenuation via absorption and scattering losses. Triplet-triplet annihilation upconversion (TTA-UC), a process which allows for low energy photons to be converted to high energy photons, is poised to overcome these challenges by allowing for precise spatial generation of high energy photons due to its nonlinear nature. With a wide range of sensitizer and annihilator motifs available for TTA-UC, many researchers seek to integrate these materials in solution or solid-state applications. In this Review, we discuss nanoengineering deployment strategies and highlight their uses in recent state-of-the-art examples of TTA-UC integrated in both solution and solid-state applications. Considering both implementation tactics and application-specific requirements, we identify critical needs to push TTA-UC-based applications from an academic curiosity to a scalable technology.
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Affiliation(s)
- Tracy Schloemer
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Pournima Narayanan
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
- Department of Chemistry, Stanford University, Stanford, California 94305, United States
| | - Qi Zhou
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Emma Belliveau
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Michael Seitz
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
| | - Daniel N Congreve
- Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States
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6
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Zeng L, Huang L, Han J, Han G. Enhancing Triplet-Triplet Annihilation Upconversion: From Molecular Design to Present Applications. Acc Chem Res 2022; 55:2604-2615. [PMID: 36074952 DOI: 10.1021/acs.accounts.2c00307] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Photon upconversion, the process of converting low-energy photons into high-energy ones, has been widely applied for solar energy conversion, photoredox catalysis, and various biological applications such as background-free bioimaging, cancer therapy, and optogenetics. Upconversion materials that are based on triplet-triplet annihilation (TTA) are of particular interest due to their low excitation power requirements (e.g., ambient sunlight) and easily tunable excitation and emission wavelengths. Despite advances that have been made with respect to TTA upconversion (TTA-UC) in the past decade, several challenges remain for near-infrared light-activatable triplet-triplet annihilation upconversion (NIR TTA-UC). These challenges include low upconversion quantum yield, small anti-Stokes shift, and incompatibility with oxygen, the latter of which seriously limits the practical applications of NIR TTA-UC.This Account will summarize the recent research endeavors to address the above-mentioned challenges and the recent new applications. The first part of this Account highlights recent strategies of molecular design to modulate the excited states of photosensitizers and annihilators, two key factors to determine TTA-UC performance. Novel molecular engineering strategies such as the resonance energy transfer method, dimerization of dye units, and the helix twist molecular structure have been proposed to tune the excited states of photosensitizers. The obtained photosensitizers exhibited enhanced absorption of deep tissue penetrable near-infrared (NIR) light, produced a triplet excited state with elevated energy level and prolonged lifetime, and promoted intersystem crossing, leading to an upgraded TTA-UC system with significantly expanded anti-Stokes shift. With respect to the annihilator, the perylene derivatives were systematically explored, and their attached aromatic groups were found to be the key to adjusting the energy levels of both the triplet and singlet excited states. The resultant optimal TTA-UC system exhibits the highest recorded efficiency among NIR TTA-UC systems.Moreover, to resolve the oxygen-induced TTA-UC quenching, enzymatic reactions were recently introduced. More specifically, the glucose oxidase-catalyzed glucose oxidation reaction showed the ability to rapidly consume oxygen to turn on the TTA-UC luminescence in an aqueous solution. The resultant TTA-UC nanoparticle was able to detect glucose and an enzyme related to glucose metabolism in a highly specific, sensitive, and background-free manner. Further, the upconverted singlet excited state of the annihilator was directly utilized as the catalyst or the excited substrate. For example, the modification of annihilators and drug molecules with photolabile linkages can realize the long wavelength light-induced photolysis. Compared to direct short-wavelength-driven photolysis, this sensitized TTA photolysis (TTAP) exhibits superior reaction yield and lower photodamage, which are important in the release of drugs for tumor treatment in vivo. Moreover, the improved upconversion efficiency can enable the successful coupling of NIR TTA-UC with a visible light absorbing photocatalyst for NIR-driven photoredox catalysis. Compared to direct visible-light photocatalysis, TTA-UC mediated NIR photoredox catalysis showed superior product yield especially in large scale reaction systems owing to the deep penetration power of NIR light. More interestingly, among a few promising technology applications, three-dimensional (3D) printing based on photopolymerization can operate with faster speed and energy-input several orders of magnitude lower when the two-photon polymerization is replaced with TTA-UC mediated polymerization. We believe this Account will spur interest in the further development and application of TTA-UC in the areas of energy, chemistry, material science, and biology.
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Affiliation(s)
- Le Zeng
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
| | - Ling Huang
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States.,Tianjin Key Laboratory of Biosensing and Molecular Recognition, Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071, P. R. China.,Haihe Laboratory of Sustainable Chemical Transformations, Tianjin 300192, P. R. China
| | - Jinfeng Han
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
| | - Gang Han
- Department of Biochemistry and Molecular Biotechnology, University of Massachusetts Chan Medical School, Worcester, Massachusetts 01605, United States
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7
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Three-dimensional direct-writing via photopolymerization based on triplet—triplet annihilation. Sci China Chem 2022. [DOI: 10.1007/s11426-022-1380-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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8
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Fu Q, Rui J, Fang J, Ni Y, Fang L, Lu C, Xu Z. Triplet‐triplet Annihilation Up‐conversion Luminescent Assisted Free‐radical Reactions of Polymers Using Visible Light. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Qiang Fu
- State Key Laboratory of Materials‐Oriented Chemical Engineering College of Materials Science and Engineering Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) Nanjing Tech University Nanjing 210009 P.R. China
| | - Jiaqiang Rui
- State Key Laboratory of Materials‐Oriented Chemical Engineering College of Materials Science and Engineering Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) Nanjing Tech University Nanjing 210009 P.R. China
| | - Jiaojiao Fang
- State Key Laboratory of Materials‐Oriented Chemical Engineering College of Materials Science and Engineering Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) Nanjing Tech University Nanjing 210009 P.R. China
| | - Yaru Ni
- State Key Laboratory of Materials‐Oriented Chemical Engineering College of Materials Science and Engineering Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) Nanjing Tech University Nanjing 210009 P.R. China
| | - Liang Fang
- State Key Laboratory of Materials‐Oriented Chemical Engineering College of Materials Science and Engineering Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) Nanjing Tech University Nanjing 210009 P.R. China
| | - Chunhua Lu
- State Key Laboratory of Materials‐Oriented Chemical Engineering College of Materials Science and Engineering Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) Nanjing Tech University Nanjing 210009 P.R. China
| | - Zhongzi Xu
- State Key Laboratory of Materials‐Oriented Chemical Engineering College of Materials Science and Engineering Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu Collaborative Innovation Center for Advanced Inorganic Function Composites Nanjing Tech University Nanjing 210009 P. R. China
- Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM) Nanjing Tech University Nanjing 210009 P.R. China
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9
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Sanders SN, Schloemer TH, Gangishetty MK, Anderson D, Seitz M, Gallegos AO, Stokes RC, Congreve DN. Triplet fusion upconversion nanocapsules for volumetric 3D printing. Nature 2022; 604:474-478. [PMID: 35444324 DOI: 10.1038/s41586-022-04485-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 01/28/2022] [Indexed: 12/19/2022]
Abstract
Three-dimensional (3D) printing has exploded in interest as new technologies have opened up a multitude of applications1-6, with stereolithography a particularly successful approach4,7-9. However, owing to the linear absorption of light, this technique requires photopolymerization to occur at the surface of the printing volume, imparting fundamental limitations on resin choice and shape gamut. One promising way to circumvent this interfacial paradigm is to move beyond linear processes, with many groups using two-photon absorption to print in a truly volumetric fashion3,7-9. Using two-photon absorption, many groups and companies have been able to create remarkable nanoscale structures4,5, but the laser power required to drive this process has limited print size and speed, preventing widespread application beyond the nanoscale. Here we use triplet fusion upconversion10-13 to print volumetrically with less than 4 milliwatt continuous-wave excitation. Upconversion is introduced to the resin by means of encapsulation with a silica shell and solubilizing ligands. We further introduce an excitonic strategy to systematically control the upconversion threshold to support either monovoxel or parallelized printing schemes, printing at power densities several orders of magnitude lower than the power densities required for two-photon-based 3D printing.
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Affiliation(s)
| | - Tracy H Schloemer
- Rowland Institute at Harvard University, Cambridge, MA, USA.,Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | | | | | - Michael Seitz
- Rowland Institute at Harvard University, Cambridge, MA, USA.,Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | - Arynn O Gallegos
- Department of Electrical Engineering, Stanford University, Stanford, CA, USA
| | | | - Daniel N Congreve
- Rowland Institute at Harvard University, Cambridge, MA, USA. .,Department of Electrical Engineering, Stanford University, Stanford, CA, USA.
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10
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Imperiale CJ, Green PB, Hasham M, Wilson MWB. Ultra-small PbS nanocrystals as sensitizers for red-to-blue triplet-fusion upconversion. Chem Sci 2021; 12:14111-14120. [PMID: 34760195 PMCID: PMC8565365 DOI: 10.1039/d1sc04330g] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 09/28/2021] [Indexed: 11/21/2022] Open
Abstract
Photon upconversion is a strategy to generate high-energy excitations from low-energy photon input, enabling advanced architectures for imaging and photochemistry. Here, we show that ultra-small PbS nanocrystals can sensitize red-to-blue triplet-fusion upconversion with a large anti-Stokes shift (ΔE = 1.04 eV), and achieve max-efficiency upconversion at near-solar fluences (I th = 220 mW cm-2) despite endothermic triplet sensitization. This system facilitates the photo-initiated polymerization of methyl methacrylate using only long-wavelength light (λ exc: 637 nm); a demonstration of nanocrystal-sensitized upconversion photochemistry. Time-resolved spectroscopy and kinetic modelling clarify key loss channels, highlighting the benefit of long-lifetime nanocrystal sensitizers, but revealing that many (48%) excitons that reach triplet-extracting carboxyphenylanthracene ligands decay before they can transfer to free-floating acceptors-emphasizing the need to address the reduced lifetimes that we determine for molecular triplets near the nanocrystal surface. Finally, we find that the inferred thermodynamics of triplet sensitization from these ultra-small PbS quantum dots are surprisingly favourable-completing an advantageous suite of properties for upconversion photochemistry-and do not vary significantly across the ensemble, which indicates minimal effects from nanocrystal heterogeneity. Together, our demonstration and study of red-to-blue upconversion using ultra-small PbS nanocrystals in a quasi-equilibrium, mildly endothermic sensitization scheme offer design rules to advance implementations of triplet fusion, especially where large anti-Stokes wavelength shifts are sought.
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Affiliation(s)
| | - Philippe B Green
- University of Toronto, Department of Chemistry Toronto ON M5S 3H6 Canada
| | - Minhal Hasham
- University of Toronto, Department of Chemistry Toronto ON M5S 3H6 Canada
| | - Mark W B Wilson
- University of Toronto, Department of Chemistry Toronto ON M5S 3H6 Canada
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11
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Sun J, Li W, Hou Y, Zhang X, Gao Z, Wang B, Zhao J. a-PET and Weakened Triplet-Triplet Annihilation Self-Quenching Effects in Benzo-21-Crown-7-Functionalized Diiodo-BODIPY. ACS OMEGA 2021; 6:28356-28365. [PMID: 34723032 PMCID: PMC8552471 DOI: 10.1021/acsomega.1c04540] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/01/2021] [Indexed: 06/13/2023]
Abstract
Weakening the triplet-triplet annihilation (TTA) self-quenching effect induced by sensitizers remains a tremendous challenge due to the very few investigations carried out on them. Herein, benzo-21-crown-7 (B21C7)-functionalized 2,6-diiodo-1,3,5,7-tetramethyl-8-phenyl-4,4-difluoroboradiazaindacene (DIBDP) was synthesized to investigate the influences of huge bulks and electron-rich cavities of B21C7 moieties on the fluorescence emission and triplet-state lifetimes of DIBDP moieties. Density functional theory (DFT)/time-dependent DFT (TDDFT) computable results preliminarily predicted that B21C7 moieties had influences on the fluorescence emissions of DIBDP moieties but not on their localization of triplet states of B21C7-functionalized DIBDP (B21C7-DIBDP). The UV-vis absorption spectra, fluorescence emission spectra, and cyclic voltammograms verified that there was an electron-transfer process from the B21C7 moiety to the DIBDP moiety in B21C7-DIBDP. However, the calculated results of ΔG CS and E CS values and nanosecond time-resolved transient absorption spectra demonstrated that the electron-transfer process from the B21C7 moiety to the DIBDP moiety in B21C7-DIBDP had direct influences on the fluorescence emission of DIBDP moieties but not on the triplet states of DIBDP moieties. The experimental values of triplet-state lifetimes of B21C7-DIBDP were obviously longer than those of DIBDP at a high concentration (1.0 × 10-5 M); however, the fitted values of intrinsic triplet-state lifetimes of B21C7-DIBDP were slightly greater than those of DIBDP in the same solvent. These results demonstrated that the steric hindrance of B21C7 moieties could weaken the TTA self-quenching effect of DIBDP moieties at a high concentration and the a-PET effect induced a proportion of the produced singlet states of DIBDP moieties and could not emit fluorescence in the form of radiation transition but they could be transformed into triplet states through intersystem crossing (ISC) processes due to the iodine atoms in the DIBDP moiety. The stronger a-PET effects in polar solvents induced smaller fluorescence quantum yields so that more singlet states of DIBDP moieties were transformed into triplet states to weaken the TTA self-quenching effects.
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Affiliation(s)
- Jifu Sun
- College
of Chemical and Biological Engineering, Shandong University of Science and Technology, J2-424, 579 Qianwangang Road, Qingdao 266590, P. R. China
| | - Weixu Li
- College
of Chemical and Biological Engineering, Shandong University of Science and Technology, J2-424, 579 Qianwangang Road, Qingdao 266590, P. R. China
| | - Yuqi Hou
- State
Key Laboratory of Fine Chemicals, Dalian
University of Technology, 2 Ling-Gong Road, Dalian 116024, P. R. China
| | - Xue Zhang
- State
Key Laboratory of Fine Chemicals, Dalian
University of Technology, 2 Ling-Gong Road, Dalian 116024, P. R. China
| | - Zhongzheng Gao
- College
of Chemical and Biological Engineering, Shandong University of Science and Technology, J2-424, 579 Qianwangang Road, Qingdao 266590, P. R. China
| | - Bo Wang
- College
of Chemical and Biological Engineering, Shandong University of Science and Technology, J2-424, 579 Qianwangang Road, Qingdao 266590, P. R. China
| | - Jianzhang Zhao
- State
Key Laboratory of Fine Chemicals, Dalian
University of Technology, 2 Ling-Gong Road, Dalian 116024, P. R. China
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Hussain M, El-Zohry AM, Hou Y, Toffoletti A, Zhao J, Barbon A, Mohammed OF. Spin-Orbit Charge-Transfer Intersystem Crossing of Compact Naphthalenediimide-Carbazole Electron-Donor-Acceptor Triads. J Phys Chem B 2021; 125:10813-10831. [PMID: 34542290 DOI: 10.1021/acs.jpcb.1c06498] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Compact electron donor-acceptor triads based on carbazole (Cz) and naphthalenediimide (NDI) were prepared to study the spin-orbit charge-transfer intersystem crossing (SOCT-ISC). By variation of the molecular conformation and electron-donating ability of the carbazole moieties, the electronic coupling between the two units was tuned, and as a result charge-transfer (CT) absorption bands with different magnitudes were observed (ε = 4000-18 000 M-1 cm-1). Interestingly, the triads with NDI attached at the 3-C position or with a phenyl spacer at the N position of the Cz moiety, thermally activated delayed fluorescence (TADF) was observed. Femtosecond transient absorption (fs-TA) spectroscopy indicated fast electron transfer (0.8-1.5 ps) from the Cz to NDI unit, followed by population of the triplet state (150-600 ps). Long-lived triplet states (up to τT = 45-50 μs) were observed for the triads. The solvent-polarity-dependent singlet-oxygen quantum yield (ΦΔ) is 0-26%. Time-resolved electron paramagnetic resonance (TREPR) spectral study of TADF molecules indicated the presence of the 3CT state for NDI-Cz-Ph (zero-field-splitting parameter D = 21 G) and an 3LE state for NDI-Ph-Cz (D = 586 G). The triads were used as triplet photosensitizers in triplet-triplet annihilation upconversion by excitation into the CT absorption band; the upconversion quantum yield was ΦUC = 8.2%, and there was a large anti-Stokes shift of 0.55 eV. Spatially confined photoexcitation is achieved with the upconversion using focusing laser beam excitation, and not the normally used collimated laser beam, i.e., the upconversion was only observed at the focal point of the laser beam. Photo-driven intermolecular electron transfer was demonstrated with reversible formation of the NDI-• radical anion in the presence of the sacrificial electron donor triethanolamine.
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Affiliation(s)
- Mushraf Hussain
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, P. R. China.,NUIST Reading Academy, Nanjing University of Information Science and Technology, Nanjing 210044, Jiangsu, P. R. China
| | - Ahmed M El-Zohry
- KAUST Solar Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia.,Department of Physics - AlbaNova Universitetscentrum, Stockholm University, SE-10691 Stockholm, Sweden
| | - Yuqi Hou
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, P. R. China
| | - Antonio Toffoletti
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Via Marzolo, 1, 35131 Padova, Italy
| | - Jianzhang Zhao
- State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, P. R. China
| | - Antonio Barbon
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, Via Marzolo, 1, 35131 Padova, Italy
| | - Omar F Mohammed
- KAUST Solar Center, Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
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