Dual nutraceutical nanohybrids of folic acid and calcium containing layered double hydroxides

• Published in: Journal of solid state chemistry 2016-01, Vol.233, p.125-132
• Main Authors: Kim, Tae-Hyun, Oh, Jae-Min
• Format: Article
• Language: English
• Subjects: CALCIUM; Calcium containing layered double hydroxide; CLATHRATES; EMISSION SPECTROSCOPY; Exfoliation-reassembly; FOLIC ACID; FOURIER TRANSFORMATION; HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY; HYBRIDIZATION; HYDROXIDES; INFRARED SPECTRA; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; INTERACTIONS; Intercalation; ION EXCHANGE; IONS; LAYERS; Nutraceutical nanohybrids; SCANNING ELECTRON MICROSCOPY; SOLIDS; THERMAL GRAVIMETRIC ANALYSIS; ULTRAVIOLET SPECTRA; VISIBLE SPECTRA; X RADIATION; X-RAY DIFFRACTION
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1016/j.jssc.2015.10.019

Dual nutraceutical nanohybrids consisting of organic nutrient, folic acid (FA), and mineral nutrient, calcium, were prepared based on layered double hydroxide (LDH) structure. Among various hybridization methods such as coprecipitation, ion exchange, solid phase reaction and exfoliation-reassembly, it was found that exfoliation-reassembly was the most effective in terms of intercalation of FA moiety between Ca-containing LDH layers. X-ray diffraction patterns and infrared spectra indicated that FA molecules were well stabilized in the interlayer space of LDHs through electrostatic interaction. From the atomic force and scanning electron microscopic studies, particle thickness of LDH was determined to be varied with tens, a few and again tens of nanometers in pristine, exfoliated and reassembled state, respectively, while preserving particle diameter. The result confirmed layer-by-layer hybrid structure of FA and LDHs was obtained by exfoliation-reassembly. Solid UV–vis spectra showed 2-dimensional molecular arrangement of FA moiety in hybrid, exhibiting slight red shift in n→π* and π→π* transition. The chemical formulae of FA intercalated Ca-containing LDH were determined to Ca1.30Al(OH)4.6FA0.74·3.33H2O and Ca1.53Fe(OH)5.06FA2.24·9.94H2O by inductively coupled plasma-atomic emission spectroscopy, high performance liquid chromatography and thermogravimetry, showing high nutraceutical content of FA and Ca. [Display omitted] •We successfully intercalated FA molecules into Ca-containing LDHs.•Exfoliation-reassembly was proven to be the most effective.•The interaction between LDH and FA were studied by FT-IR and UV–vis spectra.•Thermal stability of FA were enhanced by electrostatic interaction with LDH layers.