Efficient synthesis of hydroxyl functioned polyesters from natural polyols and sebacic acid

Amphiphilic hydroxyl functioned polyester（HFP） can be used as compatibilizers for blends of starch and resins.We developed a synthetic method for effective preparation of HFPs.Water was removed by high flow rate N_2 rather than high vacuum during polycondensation of sebacic acid with xylitol,sorbitol,or mannitol in the presence of dehydrative condensation catalyst and the product is with[η]of 27.2 mL/g,M_n of 1903,M_w of 167,693,T_g of -30.5℃,T_m of 44.0℃.Weight loss is 1.73%under 200℃. The integral distributions of molecular weight are 43.6 wt%and 63.8 wt%over 10,000 and 3000,respectively.The results indicated that higher molecular weight HFP was economically synthesized.

Metal-organic framework as a multi-component sensor for detection of Fe^(3+),ascorbic acid and acid phosphatase

In this research,a hydroxyl group functionalized metal-organic framework(MOF),UiO-66-(OH)_(2),was synthesized as a "on-off-on" fluore scent switching nanoprobe for highly sensitive and selective detection of Fe^(3+),ascorbic acid(AA) and acid phosphatase(ACP).UiO-66-(OH)_(2) emits yellow-green light under ultraviolet light,when Fe^(3+) was added,Fe^(3+) was chelated with hydroxyl group,the electrons in the excited state S_1 of the MOF transferred to the half-filled 3 d orbits of Fe^(3+),resulting in fluorescence quenching because of the nonradiative electron/hole recombination annihilation.AA could reduce Fe^(3+) to Fe^(2+),which can destroy the electron transfer between UiO-66-(OH)_(2) and Fe^(3+) after AA adding,resulted in nonoccurrence of the nonradiative electron transfer,leading to the recovery of UiO-66-(OH)_(2) fluorescence intensity.The probe can also be used to detect ACP based on the enzymolysis of 2-phospho-L-ascorbic acid(AAP) to produce AA.Benefitting from the hydroxyl group and the characteristics of UiO-66,including the high porosity and large surface area,the developed UiO-66-(OH)_(2) showed extensive advantages as a fluorescent probe for detection of multi-component,such as high sensitivity and selectivity,colorimetric detection,fast response kinetics and easy to operate,economical and secure.This is the first time to use active group functionalized MOFs as a multicomponent sensor for these three substances detection.