Electrospinning Preparation and Drug‐Delivery Properties of an Up‐conversion Luminescent Porous NaYF 4 :Yb 3+ , Er 3+ @Silica Fiber Nanocomposite

Up‐conversion (UC) luminescent porous silica fibers decorated with NaYF 4 :Yb 3+ , Er 3+ nanocrystals (NCs) (denoted as NaYF 4 :Yb 3+ , Er 3+ @silica fiber) are prepared by the electrospinning process using cationic surfactant P123 as a template. Monodisperse and hydrophobic oleic acid capped β‐NaYF 4 : Yb 3+ , Er 3+ NCs are prepared by thermal decomposition methodology. Then, these NCs are transferred into aqueous solution by employing cetyltrimethylammonium bromide (CTAB) as secondary surfactant. The water‐dispersible β‐NaYF 4 :Yb 3+ , Er 3+ NCs are dispersed into precursor electrospinning solution containing P123 and tetraethyl orthosilicate (TEOS), followed by preparation of precursor fibers via electrospinning. Finally, porous α‐NaYF 4 :Yb 3+ , Er 3+ @silica fiber nanocomposites are obtained after annealing the precursor fibers containing β‐NaYF 4 :Yb 3+ , Er 3+ at 550 °C. The as‐prepared α‐NaYF 4 :Yb 3+ , Er 3+ @silica fiber possesses porous structure and UC luminescence properties simultaneously. Furthermore, the obtained nanocomposites can be used as a drug delivery host carrier and drug storage/release properties are investigated, using ibuprofen (IBU) as a model drug. The results indicate that the IBU–loaded α‐NaYF 4 :Yb 3+ , Er 3+ @silica fiber nanocomposites show UC emission of Er 3+ under 980 nm NIR laser excitation and a controlled release property for IBU. Meanwhile, the UC emission intensity of IBU–α‐NaYF 4 :Yb 3+ , Er 3+ @silica fiber system varies with the released amount of IBU.