Surface Adsorption in PEG/Hydroxyapatite and PEG/Dickite Composite Phase Change Materials

Abstract

The traditional view is that the pore structure of substrate determines the encapsulation ratio. The work proposed that surface adsorption was also a cause in this method. Polyethylene glycol/hydroxyapatite (PEG/HAP) and polyethylene glycol/dickite (PEG/D) were prepared by encapsulating polyethylene glycol (PEG) with hydroxyapatite (HAP) and dickite as substrates. The pore structures of HAP and dickite were characterized by BET and mercury intrusion porosimetry, respectively. Through SEM, XPS, FT-IR, and XRD, the process of PEG being encapsulated by the two materials was studied. The leakage cycle test was performed on PEG/HAP. The experiments proved that HAP adsorbed PEG through the surface and the surface adsorption played an essential role in the direct impregnation process. According to the distribution of PEG among HAP particles and the adsorption mechanism of HAP, a model was created to describe the encapsulation ratio in the direct impregnation process. The maximum encapsulation ratio of PEG/HAP calculated by this model is 75.98%, which is close to the actual value (74.66%).

Ag-Doped Metal–Organic Frameworks’ Heterostructure for Sonodynamic Therapy of Deep-Seated Cancer and Bacterial Infection

“…58 These results demonstrated the structural/ functional invariability of MIL after the in situ reduction of Ag NPs and the successful construction of the MIL@Ag heterostructure. To enhance the stability and biocompatibility, PEG-2000 was modified on the surface of the MIL@Ag heterostructure through the interaction of the ethers and hydroxyl groups on PEG-2000 and the amino groups on the surface of MIL@Ag, 59 and the DLS analysis, zeta potential, and FT-IR spectrum proved that the PEG-2000 was successfully functionalized to the MIL@Ag heterostructure (Figures 1D, S3, and S5B).…”