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The isothermal cold crystallization kinetics of polylactide (PLA)/nucleating agents (CaCO 3 , TiO 2 , and BaSO 4 , content from 0.5-2.0 wt %) was investigated by differential scanning calorimetry in the temperature range of 120-1248C. With blending nucleating agents, the crystallinity of PLA had a maximum crystallinity of 14.9%. Crystallization rate decreased with increasing crystallization temperature in the researched content range. The crystallization rate followed the Avrami equation with the exponent n around 4.5. From Lauritzen-Hoffman equation, the nucleation parameter K g was estimated. And from the value of K g , regime II crystallization behavior can be concluded. Then the lateral and fold surface free energy were calculated from K g .

As quite generally stated in the literature, low-molecular-weight (MW) poly(ethylene glycol) (PEG) (M n less than 2K) and α-cyclodextrin (α-CD) can lead to only crystalline precipitates (not hydrogels). However, in this study we found that: (1) adamantane monoend-functionalized low-MW PEG (Ada-PEG, M n= 1.1 or 2K) and α-CD lead to hydrogels but not to crystalline precipitates and (2) β-cyclodextrin (β-CD) surface-functionalized silica nanoparticles (β-CD−SiO2) can be well dispersed in low-MW Ada-PEG and α-CD aqueous mixtures, resulting in hybrid hydrogels. The hydrophobic aggregation of Ada-PEG in case 1 and the further functionalization of β-CD−SiO2 with PEG chains due to the inclusion complexation between β-CD and the Ada group attached to PEG in case 2 were found to play a key role as a supra-crosslink that promoted the gelation of the inclusion complexes of α-CD and the low-MW Ada-PEG. The resultant native and hybrid hydrogels retained the basic characteristics of the supramolecular physical hydrogels, especially the shear-thinning property. The mechanical strength and the viscosity of the hybrid hydrogel were greatly improved in comparison with those of the corresponding native hydrogels.