Antifouling composites with self-adaptive controlled release based on an active compound intercalated into layered double hydroxides

作者：Yang, Miaosen; Gu, Lianghua; Yang, Bin; Wang, Li; Sun, Zhiyong^*; Zheng, Jiyong; Zhang, Jinwei; Hou, Jian; Lin, Cunguo^*

来源：Applied Surface Science, 2017, 426: 185-193.

DOI：10.1016/j.apsusc.2017.07.207

• Layered double hydroxide
• Antifoulant
• Intercalation
• Self-adaptive controlled release
• Antifouling property

This paper reports a novel method to prepare the antifouling composites with properties of self-adaptive controlled release (defined as control the release rate autonomously and adaptively according to the change of environmental conditions) by intercalation of sodium paeonolsilate (PAS) into MgAl and ZnAl layered double hydroxide (LDH) with the molar ratio (M2+/M3+) of 2:1 and 3:1, respectively. The powder X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) confirm the intercalation of PAS into the galleries of LDH. The controlled release behavior triggered by temperature for the PAS-LDH composites has been investigated, and the results show that the release rate of all PAS-LDH composites increases as the increase of temperature. However, the MgAl-PAS-LDH composites (Mg2Al-PAS-LDH and Mg3Al-PAS-LDH) exhibit the increased release rate of 0.21 ppm/degrees C from 15 to 30 degrees C in 3.5% NaCl solution, more than three times of the ZnAl-PAS-LDH composites (0.06 ppm/degrees C), owing to the confined microenvironment influenced by metal types in LDH layers. In addition, a possible diffusion-controlled process with surface diffusion, bulk diffusion and heterogeneous flat surface diffusion has been revealed via fitting four kinetic equations. Moreover, to verify the practical application of the PAS-LDH composites, a model coating denoted as Mg2Al-PAS-LDH coating was fabricated. The release result displays that the release rate increases or decreases as temperature altered at 15 and 25 degrees C alternately, indicating its self-adaptive controlled release behavior with temperature. Moreover, the superior resistance to the settlement of Ulva spores at 15 and 25 degrees C was observed for the Mg2Al-PAS-LDH coating, as a result of the controllable release of antifoulant. Therefore, this work provides a facile and effective method for the fabrication of antifouling composites with self-adaptive controlled release behavior in response to temperature, which can be used to prolong the lifetime of antifouling coatings.

• 出版日期2017-12-31
• 单位中国船舶重工集团公司第七二五研究所