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Electrospun Semi-Alicyclic Polyimide Nanofibrous Membrane: High-Reflectance and High-Whiteness with Superior Thermal and Ultraviolet Radiation Stability for Potential Applications in High-Power UV-LEDs
- Source :
- Nanomaterials, Nanomaterials, Vol 11, Iss 1977, p 1977 (2021), Volume 11, Issue 8
- Publication Year :
- 2021
- Publisher :
- MDPI AG, 2021.
-
Abstract
- Polymeric nanofibrous membranes (NFMs) with both high whiteness and high thermal and ultraviolet (UV) stability are highly desired as reflectors for ultraviolet light-emitting diodes (UV-LEDs) devices. In the current work, a semi-alicyclic and fluoro-containing polyimide (PI) NFM with potential application in such kinds of circumstances was successfully fabricated from the organo-soluble PI resin solution via a one-step electrospinning procedure. In order to achieve the target, a semi-alicyclic PI resin was first designed and synthesized from an alicyclic dianhydride, 3,4-dicarboxy-1,2,3,4,5,6,7,8-decahydro-1-naphthalenesuccinic dianhydride (or hydrogenated tetralin dianhydride, HTDA), and a fluoro-containing diamine, 2,2-bis[4-(4-amino-phenoxy)phenyl]hexafluoropropane (BDAF), via an imidization procedure. The derived PI (HTDA-BDAF) resin possessed a number-average molecular weight (Mn) higher than 33,000 g/mol and was highly soluble in polar aprotic solvents, such as N,N-dimethylacetamide (DMAc). The electrospinning solution was prepared by dissolving the PI resin in DMAc at a solid content of 25–35 wt%. For comparison, the conventional high-whiteness polystyrene (PS) NFM was prepared according to a similar electrospinning procedure. The thermal and UV stability of the derived PI and PS NFMs were investigated by exposure under the UV-LED (wavelength: 365 nm) irradiation. Various thermal evaluation results indicated that the developed PI (HTDA-BDAF) NFM could maintain both the high reflectance and high whiteness at elevated temperatures. For example, after thermal treatment at 200 °C for 1 h in air, the PI (HTDA-BDAF) NFM exhibited a reflectance at a wavelength of 457 nm (R457) of 89.0%, which was comparable to that of the pristine PI NMF (R457 = 90.2%). The PI (HTDA-BDAF) NFM exhibited a whiteness index (WI) of 90.88, which was also close to that of the pristine sample (WI = 91.22). However, for the PS NFM counterpart, the R457 value decreased from the pristine 88.4% to 18.1% after thermal treatment at 150 °C for 1 h, and the sample became transparent. The PI NFM maintained good optical and mechanical properties during the high dose (2670 J/cm2) of UV exposure, while the properties of the PS NFM apparently deteriorated under the same UV aging.
- Subjects :
- Materials science
General Chemical Engineering
nanofibrous membrane
02 engineering and technology
Thermal treatment
010402 general chemistry
medicine.disease_cause
polyimide
01 natural sciences
Article
chemistry.chemical_compound
Alicyclic compound
Diamine
reflectivity
medicine
General Materials Science
QD1-999
electrospinning
chemistry.chemical_classification
021001 nanoscience & nanotechnology
Electrospinning
0104 chemical sciences
Chemistry
Membrane
chemistry
Polystyrene
UV-LED
0210 nano-technology
Ultraviolet
Polyimide
Nuclear chemistry
Subjects
Details
- ISSN :
- 20794991
- Volume :
- 11
- Database :
- OpenAIRE
- Journal :
- Nanomaterials
- Accession number :
- edsair.doi.dedup.....ee0719e7a120e0b9a08ceb76aa7e50e0
- Full Text :
- https://doi.org/10.3390/nano11081977