Integration of β-NaYF4 Upconversion Nanoparticles into Polymers for Polymer Optical Fiber Applications

Abstract

Producing active polymer optical fibers (POFs) is a key step towards new applications such as fluorescent fiber solar concentrators (FFSCs), sensors, contactless coupling devices, or fiber integrated light sources and lasers. Therefore, integration of fluorescent nanoparticles into the polymer matrix is necessary and becomes accessible via in situ polymerization. For optical applications, the polymer has to fulfill various requirements such as chemical and physical stability, optical transparency in the application-relevant spectral region as well as a good synthetic accessibility. A common material for these is poly(methyl methacrylate) (PMMA). The β-phase NaYF 4 :Yb 3+ ,Er 3+ upconversion nanoparticles (UCNP) were synthesized from the rare earth salts via thermal decomposition method in high-boiling point solvent 1-octadecene and capping agent oleic acid. Current results show hazy samples of the polymer with integrated nanoparticles made from monomer solution of methyl methacrylate. However, further optical tuning such as increasing the transparency of the bulk samples by changing the monomer solution to non-polar n-butyl methacrylate (nButMA) or cyclohexyl methacrylate (CHMA) or further optimization of the UCNP shell could lead to more suitable polymer bulk samples.

Upconversion Nanocrystal Doped Polymer Fiber Thermometer

“…In this section, we will provide a brief description of the manufacturing process of the NC doped POF. A detailed description can be found in [ 8 ]. In order to incorporate the NC in a polymer matrix, an in situ polymerisation process was chosen.…”

“…In a second step, the fiber was coated with acrylate and drawn through a nozzle, leading to fiber diameters of 1000 m. The cladding was cured with UV light afterwards. Further details on the manufacturing and preparation process for the POFs can be found in [ 8 , 14 , 15 , 16 ]. An exemplary illustration of different comonomer polymer preforms as well as emission from a doped fiber excited with 976 nm is shown in Figure 4 .…”

“… Characterization of the size distribution and the crystal phase of the manufactured NCs by using TEM and XRD, respectivly. Further details can be found in [ 8 ]. …”

“…NTs based on Er,Yb:YNaF are highly sensitive to temperature changes, exhibiting one of the best sensitivities of NTs with 1.2–1.4%/K. The doping of POFs with this NC is chemically feasible and has recently been demonstrated [ 8 ]. Setting aside the fiber design, polymer doped with NT could open up additional application areas in additive manufacturing, as flexible light guiding structures can be manufactured from polymer by 3-D printing [ 9 ] and hence be used in integrated photonics devices.…”

Looking at Sc(III) and Y(III) Lattices for Upconversion Nanoparticles Complemented by Eu(III) Down-Shifting Luminescence

“…Lanthanide-based upconversion luminescence (UCL) is a nonlinear optical process in which the emission of high-energy photons (UV or visible) occurs after a sequential absorption of two or more low-energy photons (NIR or IR). − After the experiments of Auzel, Ovsyankin, and Feofilov in the mid-1960s about this phenomenon, this research field has attracted increasing interest because of its potential for novel, unique applications in sensing, diagnostics, or medicinal treatments. , Lanthanide-doped upconversion nanoparticles (UCNPs) are unique UC materials by means of their electronic structure. Ln 3+ -based UCNPs exhibit unique spectroscopic features like narrow emission bands, long luminescence lifetimes, etc. ,, Moreover, compared to conventional fluorescent probes such as organic dyes or quantum dots, UCNPs show other advantages like high chemical stability, large anti-Stokes shift, no interference from autofluorescence of biological tissue, absence of blinking, no photobleaching, and distinctly reduced damage to biological samples due to excitation in the NIR region. ,,, With these outstanding properties, UCNPs found applications in numerous fields such as security encoding, bioimaging, drug delivery, energy transfer biosensing, single-molecule sensing, photodynamic therapy, super-resolution microscopy, optical communication, display technology, and solar cells. − ,− …”