Zhu Zhengxi, Anacker Jessica L, Ji Shengxiang, Hoye Thomas R, Macosko Christopher W, Prud'homme Robert K
Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, USA.
Langmuir. 2007 Oct 9;23(21):10499-504. doi: 10.1021/la701420z. Epub 2007 Sep 7.
Reactive impingement mixing was employed to produce polymer-protected nanoparticles. Amphiphilic block copolymer was formed in situ by reactive coupling of hydrophobic and hydrophilic blocks. Simultaneously, a hydrophobic compound and the copolymer coprecipitated to form nanoparticles in the range of 100 nm. Specifically, beta-carotene was stabilized by the amphiphilic diblock copolymer, formed from the reaction of an amino-terminated hydrophilic block, poly(ethylene glycol) (PEG-NH2), with an acid chloride-terminated hydrophobic block, either poly(epsilon-caprolactone) (PCL-COCl) or polystyrene (PS-COCl). Spherical particles were observed by scanning and cryogenic transmission electron microscopy. Process conditions, including feed concentration of beta-carotene and feed concentrations of polymeric stabilizers, had little or no effect on average particle sizes over the range studied. Further, for Reynolds numbers greater than 500 the feed flow rates also had no effect. The effect of glass transition temperature (Tg) of the hydrophobic polymer on morphology and particle formation mechanism is discussed.
采用反应性冲击混合法制备聚合物保护的纳米颗粒。通过疏水和亲水嵌段的反应性偶联原位形成两亲性嵌段共聚物。同时，一种疏水化合物与共聚物共沉淀形成100纳米范围内的纳米颗粒。具体而言，β-胡萝卜素由两亲性二嵌段共聚物稳定，该共聚物由氨基封端的亲水性嵌段聚乙二醇（PEG-NH2）与酰氯封端的疏水性嵌段聚己内酯（PCL-COCl）或聚苯乙烯（PS-COCl）反应形成。通过扫描和低温透射电子显微镜观察到球形颗粒。在所研究的范围内，包括β-胡萝卜素的进料浓度和聚合物稳定剂的进料浓度在内的工艺条件对平均粒径几乎没有影响。此外，对于雷诺数大于500的情况，进料流速也没有影响。讨论了疏水性聚合物的玻璃化转变温度（Tg）对形态和颗粒形成机制的影响。
