应用化学

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一种基于立构复合及自组装方法构筑的耐受性疏水表面

吴单,王婷兰,王婧琳,姚远(),唐颂超()   

  1. 华东理工大学材料科学与工程学院 上海 200237
  • 收稿日期:2019-02-23 出版日期:2019-06-01
  • 通讯作者: 姚远,唐颂超
  • 基金资助:
    国家自然科学基金(51573088)和上海市重大项目(18JC1410802)资助项目

A Durable Hydrophobic Surface Fabricated Through Stereocomplexation and Self-assembly

WU Dan,WANG Tinglan,WANG Jinglin,YAO Yuan(),TANG Songchao()   

  1. School of Materials Science and Engineering,East China University of Science and Technology,Shanghai 200237,China
  • Received:2019-02-23 Published:2019-06-01
  • Contact: YAO Yuan,TANG Songchao
  • Supported by:
    Supported by the National Natural Science Foundation of China(No.51573088), the Major Projects in Shanghai(No.18JC1410802)

摘要:

利用丙交酯开环聚合法制备了聚(D-乳酸)-聚二甲基硅氧烷-聚(D-乳酸)(PDLA-b-PDMS-b-PDLA)三嵌段聚合物,将其溶液涂覆至充斥着非溶剂蒸汽的聚(L-乳酸)(PLLA)表面,PDLA-b-PDMS-b-PDLA在缓慢沉积的过程中与PLLA发生立构复合及自组装,得到由立构复合的亚微米颗粒组装体形成的聚乳酸表面疏水层。 研究了聚合物溶液的质量浓度、组装温度以及溶剂对聚乳酸表面的微观形貌和疏水性能产生的影响。 结果表明,随着PDLA-b-PDMS-b-PDLA聚合物溶液质量浓度的增加,可以实现聚乳酸表面Wenzel-Cassie-Wenzel的疏水行为转变;在0 ℃下,可得到最大疏水角151°的疏水层;选择对聚合物溶解性、挥发速度不同的溶剂,得到的表面微观形貌和疏水性也不同。 由于聚乳酸制品表面的PLLA链段与亚微米颗粒中的PDLA链段也能够立构复合,因此该表面疏水层对刀刮、胶带剥离和手指擦拭测试均表现出良好的耐受性。

关键词: 聚乳酸, 立构复合, 自组装, 疏水表面

Abstract:

Triblock copolymer, poly(D-lactide)-b-polydimethylsiloxane-b-poly(D-lactide)(PDLA-b-PDMS-b-PDLA), was synthesized by ring-opening polymerization of D-lactide, and then its solution was coated onto the surface of poly(L-lactide)(PLLA) in a vail filled with non-solvent vapor. During the slow deposition process, PDMS with low surface energy was introduced to the PLLA surface. Meanwhile, PDLA segments stereocomplexed with the PLLA segments on the surface. A hydrophobic layer composed of stereocomposite submicron particles was formed on the surface of PLLA through the stereocomplexation between PLLA and PDLA-b-PDMS-b-PDLA and the self-assembly of PDLA-b-PDMS-b-PDLA. The influences of polymer solution concentration, assembly temperature and solvent on the surface morphology and the hydrophobicity of PLLA surface were further studied. With the increase of the concentration of PDLA-b-PDMS-b-PDLA, the hydrophobic behavior of the surface showed a transformation from Wenzel to Cassie status, and then returned to Wenzel status. When the assembly temperature was 0 ℃ and a 2 g/L PDLA-b-PDMS-b-PDLA/CH2Cl2 solution was deposited on the PLLA surface, the contact angle was 151°. When the assembly temperature raised to 30 ℃, the surface contact angle was 144° and the rolling angle was 5°. The obtained surface morphology and hydrophobicity were also varied with solvents with different solubility and volatilization rate. In addition, the hydrophobic surface of PLLA products can be achieved by means of stereocomplexation and self-assembly. By varying the concentration of PDLA-b-PDMS-b-PDLA solutions, the surface of PLLA products would eventually assembles into a “pearl necklace” shaped bicontinuous network structure. Because the surface of PLLA and the submicron particles were all connected with stereocomplexed PLLA/PDLA chains, the hydrophobic layer exhibited good durability against knife-scratch, tape-peel and finger-wipe tests. After the knife-scratch test and the tape peel test, the contact angle of the surface of the PLLA products was only slightly reduced, and the micro-spherical appearance of the PLLA surface existed after test.

Key words: poly(L-lactide), stereocomplex, self-assembly, hydrophobic surface