One-pot synthesis of micron-sized polybetaine particles; innovative use of supercritical carbon dioxide
One-pot synthesis of micron-sized polybetaine particles; innovative use of supercritical carbon dioxide
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DOI：
10.1039/c7py00455a
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发表时间：
2017-08
影响因子：
4.6
通讯作者：
Simon P. Bassett;N. Birkin;James Jennings;Emma Chapman;R. O’Reilly;S. Howdle;H. Willcock
中科院分区：
文献类型：
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作者：
Simon P. Bassett;N. Birkin;James Jennings;Emma Chapman;R. O’Reilly;S. Howdle;H. Willcock
聚甜菜碱表现出独特的性能，结合抗微生物和低蛋白质污染行为，以及生物相容性。迄今为止，已证明合成>50 nm的聚甜菜碱颗粒极具挑战性，标准乳液和分散技术不成功。在这里，我们提出了第一个报道的合成微米级的，离散的交联聚甜菜碱颗粒，使用在超临界CO2与甲醇作为共溶剂的聚合。只有当使用scCO2萃取原位有效去除甲醇时才产生离散颗粒。发现相对高的交联剂初始浓度（10wt%）导致最良好限定的颗粒，并且随着交联剂初始浓度的降低，颗粒完整性降低。在3.0 × 10−2 mol L−1和1.8 × 10−1 mol L−1之间的单体负载导致离散的微米尺寸的颗粒，随着单体负载的进一步增加，发生显著的聚集。通过SEM分析观察到优化的颗粒的球形形态和极低的尺寸分散性。该颗粒很容易再分散在水溶液中，光散射测量证实了它们的低尺寸分散性。
Polybetaines exhibit unique properties combining anti-polyelectrolyte and low protein fouling behaviour, as well as biocompatibility. To date, the synthesis of polybetaine particles >50 nm has proved to be extremely challenging with standard emulsion and dispersion techniques being unsuccessful. Here we present the first reported synthesis of micron-sized, discrete cross-linked polybetaine particles, using polymerisation in scCO2 with methanol as a co-solvent. Discrete particles are produced only when the methanol is efficiently removed in situ using scCO2 extraction. A relatively high crosslinking agent initial concentration (10 wt%) was found to result in the most well defined particles, and particle integrity reduced as the crosslinking agent initial concentration was decreased. A monomer loading of between 3.0 × 10−2 mol L−1 and 1.8 × 10−1 mol L−1 resulted in discrete micron sized particles, with significant agglomoration occuring as the monomer loading was increased further. A spherical morphology and extremely low size dispersity was observed by SEM analysis for the optimised particles. The particles were readily re-dispersed in aqueous solution and light scattering measurements confirmed their low size dispersity.