Investigation on surface activity of cyclodextrins grafting cellulose beads through phenolphthalein probe molecule

Abstract

aThe binding constants (K a ) of phenolphthalein/β-cyclodextrin, phenolphthalein/(2-hydroxypropyl)-β-cyclodextrin, and phenolphthalein/(2,6-dimethyl)-β-cyclodextrin complexes were measured by ultraviolet-visible spectrophotometer. By regression of van't Hoff plot, thermodynamic parameters ( H • and S • ) of these complexes' formation were obtained. Based on these parameters, steric hindrance influence, spontaneous and enthalpically driven process for the interaction of phenolphthalein with cyclodextrins were further proved, and phenolphthalein, as a probe molecule, was used to determinate cyclodextrins' content due to less than 0.6% relative standard deviation of these quantifications and recoveries with the range of 90 ∼ 103%. Using microfiltration technique, the detection phenolphthalein probe technique was applied on the determination of surface activity of cyclodextrins grafting cellulose beads by different polycarboxylic acids, and the results exhibit the real encapsulation activity of the cyclodextrins containing these spherical functional biomaterials.

Synthesis and investigation of a self-assembled hydrogel based on hydroxyethyl cellulose and itsin vitroibuprofen drug release characteristics

“…47,48 For determination, 0.02 g of dried b-CDP/IBU was dissolved in 5 mL of 10 À3 mol L À1 phenolphthalein in a 50 mL comparison tube and then 15 mL of a Na 2 CO 3 -NaHCO 3 buffer solution (pH ¼ 10.5) was added. The mixed solution was kept in the dark and stirred for 12 h for complete inclusion equilibrium.…”

Preparation, characterization and photocatalytic study of wood-flour/β-cyclodextrin/TiO2 hybrid composite

“…In details, b-CD/TiO 2 composite was synthesized by the addition of TiO 2 (2.0 g) and b-CD (1.8 g) into 100 mL of distilled water, followed by irradiating by a 250-W high-pressure mercury lamp for 30 min (Montalti et al 2006). The precipitation was centrifuged and washed with 100 mL of distilled water for 2-3 times until the b-CD could not be detected by phenolphthalein probe technology (Mäkelä et al 1987;Wang et al 2011). Then the products were dried in a vacuum oven at 50°C for 12 h. WF/TiO 2 : The suspension containing WF and TiO 2 in a molar ratio of 1:1 was irradiated by a 250-W high-pressure mercury lamp for 60 min, centrifuged, washed and dried in a vacuum oven at 50°C for 12 h.…”

Research on Photocatalytic Degradation of Methyl Orange by a β-Cyclodextrin/Titanium Dioxide Composite

“…The precipitation was centrifuged and washed with 100 mL of distilled water for 2-3 times until the β-CD could not be detected by phenolphthalein probe technology. [27,28] Then the product was dried in a vacuum oven at 50 ℃ for 12 h and the weight of product was recorded. The product was ground and well homogenized in the ball mill (100 mesh) before using.…”

“…Also, our previous work of phenolphthalein probe technology was applied here. [28,29] The absorbance of the calibration solutions of CDs was measured at the wavelength of 553 nm at room temperature. The contents of β-CD (cCD) could be calculated by Eq.…”

“…[28,32] The purple phenolphthalein solution (pH=10.5) faded by mixing the β-CD/TiO2 powder in dark. The solution was kept overnight to balance.…”