Microporous polyolefin strands as controlled-release devices for mosquito repellents
Microporous polyolefin strands as controlled-release devices for mosquito repellents
复制标题
DOI：
10.1016/j.cej.2018.11.237
复制
发表时间：
2019-03-15
影响因子：
15.1
通讯作者：
Loots, Mattheus T.
中科院分区：
文献类型：
--
作者：
Mapossa, Antonio B.;Sibanda, Mthokozisi M.;Loots, Mattheus T.
非洲疟疾的主要传播媒介，即非洲按蚊。arabiensis、阿拉伯隐翅虫An.冈比亚有限公司和一个.被人类的脚臭所吸引，它们往往会咬受害者的脚踝。因此，价格实惠的驱蚊聚合物脚手镯具有持久的保护作用，可以减少感染性下肢咬伤，从而有助于降低疟疾的总体传播率。本研究探讨了将驱避剂掺入廉价的热塑性聚合物，即聚（乙烯-共-乙酸乙烯酯）（伊娃）和线性低密度聚乙烯（LLDPE），以增加驱避活性的持续时间的可能性。挥发性驱避剂需要释放到周围空气中才能有效，即它们不断流失到大气中。这意味着手镯还应该充当相对大量的活性化合物的储存器。为此，通过双螺杆挤出复合制备了含有驱蚊剂的聚合物股线。通过在冰浴中快速骤冷离开挤出机的均质聚合物排斥性熔融混合物来实现共连续相结构。相分离通过将液体排斥剂捕获在微孔聚合物基质中的亚稳分解发生。覆盖挤出的聚合物股线的皮肤状膜控制释放速率。含有至多30重量%的避蚊胺或伊卡里丁的链即使在50 ℃下老化12周后也能提供有效的防蚊虫叮咬保护。
The main vectors of malaria in Africa, i.e. An. arabiensis, An. gambiae s.s. and An. funestus, are attracted by human foot odour and they tend to bite victims in the ankle area. Hence, affordable mosquito-repellent polymer-foot bracelets with long lasting protection could reduce infective lower limb bites and therefore help to reduce the overall malaria transmission rate. This study investigated the possibility of increasing the duration of repellence activity by incorporating repellents into inexpensive thermoplastic polymers, namely poly(ethylene-co-vinyl acetate) (EVA) and linear low-density polyethylene (LLDPE). Volatile repellents need to be released into the surrounding air to be effective, i.e. they are continuously lost to the atmosphere. This means that the bracelet should also act as a reservoir for relatively large quantities of the active compound. Towards this goal, polymer strands containing mosquito repellent were prepared by twin-screw extrusion compounding. A co-continuous phase structure was achieved by rapid quenching in an ice bath of the homogeneous polymer-repellent melt mixture exiting the extruder. Phase separation occurred through spinodal decomposition that trapped the liquid repellent in the microporous polymer matrix. A skin-like membrane that covered the extruded polymer strands controlled the release rate. Strands that contained up to 30 wt-% of either DEET or Icaridin provided effective protection against mosquito bites even after 12 weeks of ageing at 50 degrees C.