Infrared light induced deep ultraviolet internal light centers for novel cost-effective 3D printing

https://doi.org/10.1016/j.jallcom.2020.158053Get rights and content

Highlights

  • Deep ultraviolet (UV) up-conversion lasing is observed from NaYF4:Yb3+/Tm3+ microcrystals.

  • Internal deep UV light centers in the polymer matrix created by upconversion is utilized for 3D printing application.

  • This 3D printing method is able to print structures directly inside the polymer matrix rather than on the surface.

Abstract

We report a novel and cost-effective 3D printing technology by using NaYF4:Yb3+/Tm3+ up-conversion microcrystals to produce internal deep ultraviolet (UV) light centers as a light curing source in the polymer matrix by near infrared light excitation. Excellent up-conversion emission from NaYF4:Yb3+/Tm3+ microcrystals is demonstrated by using microcrystals as gain medium to realize up-conversion lasing emission centered at 291, 346 and 364 nm. This 3D printing technique, in which a low cost semiconductor laser is used, is potential to print large structures at high printing efficiency.

Introduction

Up-conversion luminescence is the process of converting long-wavelength (e.g., near-infrared (NIR) light) into short-wavelength (e.g., visible light and ultraviolet (UV) light) by absorbing multiple low-energy photons to emit higher-energy photons [1], [2], [3], [4]. There are numerous types of up-conversion luminescent materials in which the lanthanide rare earth ions (Ln3+) doped up-conversion luminescent materials have unique up-conversion luminescent characteristics due to their unique atomic structures among massive up-conversion luminescent materials. Previous publications revealed that lanthanide rare earth ions doped particles are non-cytotoxic to a broad range of cell lines [5], [6]. Therefore, the rare earth up-conversion luminescent materials have tremendous applications in solar cells [7], [8], biological imaging [9], [10], three-dimensional display [11], [12], biotherapy [13], [14], [15], anti-counterfeiting technology [16], [17], 3D printing [18], [19] and photocatalysis [20], [21], [22]. NIR light excitation is of great significance in the biomedical field compared to visible light or UV light excitation. This is because absorption and scattering of NIR light are considerably low and NIR light possesses less damage, low background noise and deeper penetration depth [23], [24].

These merits are also crucial to 3D printing. 3D printing technology is a rapid prototyping manufacturing technology. Numerous 3D printing technologies have been developed in wide range of applications. Polymer 3D printing is one of the technologies that use polymer as printing material. Polymer 3D printing technologies mainly include stereo lithography apparatus (SLA), fusion deposition molding, selective laser sintering, polyjet, multi-jet fusion and bio-printing etc [25], [26], [27], [28], [29], [30], [31], [32], [33]. The application of SLA technology which is excited by UV light source is limited due to low penetration depth of UV light. Therefore the SLA technology of two-photo polymerization (2PP) by using NIR laser as a light source has been extensively studied [34], [35], [36] due to excellent penetration of NIR light, as well as the capability to break through the limits of optical diffraction [34], [37], [38]. However, this 3D printing technology still faces some drawbacks: 1) 2PP 3D printing usually uses an extremely expensive high-power femtosecond laser as an excitation source to excite organic molecules to produce two-photon absorption; 2) two-photon absorption can only be produced in a small range (usually in the nanometers to micrometers range) at sufficient high instantaneous light intensity. This will lead to extremely low printing efficient when facing larger structures.

In order to overcome these defects, we developed a novel and cost-effective 3D printing technology by using NaYF4:Yb3+/Tm3+ up-conversion microcrystals to produce internal deep UV light centers as a light curing source in the polymer matrix by NIR light excitation. This approach has several advantages over SLA and 2PP polymer 3D printing technologies: First of all, compared with SLA technology (using UV laser as light source), NIR light, which has much deeper penetration, was used as an excitation light source. As a result, 3D structures can be printed deep in the polymer matrix rather than on the surface by using our developed approach. This may extend the application of polymer 3D printing. Secondly, compared with conventional two-photon absorption polymerization 3D printing technology (using expensive high-power femtosecond laser), semiconductor laser, which is much cheaper than high-power femtosecond laser, was used in this work. This may lower down the printing cost when compared with 2PP. At last, the printing speed of this approach is much higher than that of 2PP. In addition, excellent up-conversion emission characteristics of the as prepared microcrystals was demonstrated by realizing deep UV lasing by using NaYF4:Yb3+/Tm3+ microcrystals as gain medium. This work greatly expands the application of polymer 3D printing in numerous areas such as revise large and complex defects in dental treatment.

Section snippets

Experiment

Hydrothermal is a facile, low cost, energy saving and environment friendly fabrication method that have been widely used in transition metal based nanostructures fabrication [39], [40], [41]. NaYF4:20%Yb3+, x% Tm3+ microcrystals (x=0.5, 1, 1.5, 2, 2.5) were synthesized by using hydrothermal method [42]. In a typical procedure, Y(NO3)3·6H2O(1.5224 g), Yb(NO3)3·5H2O (0.449 g) and Tm(NO3)3·5H2O (0.0111 g) were added to a 50 ml beaker containing deionized water to form a 0.5 mol/L Ln(NO3)3(Ln=Y,

Results and discussion

SEM images of NaYF4:20%Yb3+, 1%Tm3+microcrystals are shown in Fig. 1(a). It is observed that NaYF4:Yb3+/Tm3+ microcrystals are nearly hexagonal pillars. Size distribution of NaYF4:20%Yb3+, 1%Tm3+ microcrystals are given in Fig. 1(b) and (c). It is shown that the length (width) of the NaYF4:Yb3+/Tm3+ microcrystals are distributed between 4 (1.5) μm and 7.5 (5.5) μm with average length about 6(3) μm. The microcrystal structures and phase purity which are shown in Fig. 1(d) were examined by XRD.

Conclusion

In summary, NaYF4:Yb3+/Tm3+ microcrystals were fabricated by using hydrothermal method. Excellent up-conversion luminescence properties of NaYF4:Yb3+/Tm3+ microcrystals have been demonstrated by using microcrystals as gain medium to realize up-conversion lasing emission centered at 291, 346 and 364 nm. A novel cost-effective up-conversion based 3D printing technology by using the as prepared NaYF4:Yb3+/Tm3+ up-conversion microcrystals to produce internal deep UV light centers as curing source

CRediT authorship contribution statement

Wenqing Liang: Investigation, Writing - original draft, review & editing. Di Xiao: Investigation, Writing - original draft, review & editing. Wenfei Zhang: Conceptualization, Methodology, Writing - review & editing, Funding acquisition. Yiqun Ni: Writing - review & editing. Honghao Wan: Writing - review & editing. Xuesong Xu: Writing - review & editing. Shaofeng Zhang: Writing - review & editing. Shuangchen Ruan: Funding acquisition.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work was supported by National Nature Science Foundation of China (61875127), Science and Technology Projects of Shenzhen (JCYJ20170818101651195).

References (47)

  • M. Haase et al.

    Upconverting nanoparticles

    Angew. Chem. Int. Ed. Engl.

    (2011)
  • F. Auzel

    Upconversion and anti-stokes processes with f and d ions in solids

    Chem. Rev.

    (2004)
  • D.R. Gamelin et al.

    Design of luminescent inorganic materials: new photophysical processes studied by optical spectroscopy

    Acc. Chem. Res.

    (2000)
  • F. Wang et al.

    Upconversion nanoparticles in biological labeling, imaging, and therapy

    Analyst

    (2010)
  • S. Fischer et al.

    Enhancement of silicon solar cell efficiency by upconversion: optical and electrical characterization

    J. Appl. Phys.

    (2010)
  • Z. Shi et al.

    Dual functional NaYF4:Yb3+, Er3+@NaYF4:Yb3+, Nd3+ core-shell nanoparticles for cell temperature sensing and imaging

    Nanotechnology

    (2018)
  • S. Ma et al.

    Three-dimensional angiography fused with CT/MRI for multimodal imaging of nanoparticles based on Ba4Yb3F17:Lu3+,Gd3+

    Nanoscale

    (2018)
  • S. Gai et al.

    Synthesis of magnetic, up-conversion luminescent, and mesoporous core-shell-structured nanocomposites as drug carriers

    Adv. Funct. Mater.

    (2010)
  • C. Yan et al.

    Lanthanide ion doped upconverting nanoparticles: synthesis, structure and properties

    Small

    (2016)
  • Z. Chen et al.

    Photon upconversion lithography: patterning of biomaterials using near-infrared light

    Adv. Mater.

    (2015)
  • X. Yin et al.

    Three primary color emissions from single multilayered nanocrystals

    Nanoscale

    (2018)
  • S. Xie et al.

    Design of novel lanthanide-doped core–shell nanocrystals with dual up-conversion and down-conversion luminescence for anti-counterfeiting printing

    Dalton Trans.

    (2019)
  • J. Méndez-Ramos et al.

    Infrared-light induced curing of photosensitive resins through photon up-conversion for novel cost-effective luminescent 3D-printing technology

    J. Mater. Chem. C

    (2016)
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    Both the authors contributed equally to this paper.

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