Dendrimer与表面活性剂相互作用的研究进展

聚酰胺-胺(PAMAM)是目前最具应用前景的树枝状大分子(Dendrimer),它与表面活性剂相互作用后能够形成聚集体,这种聚集体能有效地改变体系的微观环境和物理化学性质。本文综述了小分子表面活性剂与Dendrimer相互作用研究方面所取得的进展,重点讨论了阴离子表面活性剂和阳离子表面活性剂与Dendrimer混合体系中溶液的疏水环境、浊度以及形成聚集体中值粒径等物理化学性质的变化,在此基础上,讨论了Dendrimer与小分子表面活性剂相互作用在机理方面所取得的研究进展,为进一步扩大Dendrimer的应用领域提供参考。     

Simulation‐Assisted Evaluation of Acetylene Effect on Macromolecular Crosslinking Rate under Polyethylene Irradiation

Gel content data on acetylene accelerated radiation crosslinking (R.A. Jones, J. Polym. Sci., Part B: Polym. Phys. 1994 , 32, 2049) have been used to illustrate a new method to determine macromolecular crosslinking and scission yields. The sol‐gel analysis data have been plotted as log(sol) versus log(dose) resulting in quite linear plots having different slopes. The linear approximations with the least squares method resulted in gel‐points with a high accuracy. Computer simulations have shown the plot slope to be dependent on relative rate of competitive macromolecular scission. The scission/crosslink ratios have been found from the plot slopes using simulation software GelSim6. As a result acetylene gas has been found to be accelerating both crosslinking and scission rates: 60 times and 130 times, respectively. Obviously, the radiation yield of radicals is increased due to acetylene inhibiting the recombination of primarily induced radicals in a cage.

Gel content vs. irradiation dose data plotted as log(sol) versus log(dose). Numbers near the curves indicate concentrations of acetylene gas (mmol · kg⁻¹).