Gul Merve, Fontana-Escartín Adrian, Arnau Marc, Sans Jordi, Lanzalaco Sonia, Armelin Elaine, Chiesa Enrica, Genta Ida, Pérez-Madrigal Maria M, Alemán Carlos
IMEM-BRT Group, Departament d'Enginyeria Química, EEBE, Universitat Politécnica de Catalunya, C/Eduard Maristany, 10-14, 08019 Barcelona, Spain.
Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, 08930 Barcelona, Spain.
ACS Appl Polym Mater. 2024 Dec 10;6(24):15070-15081. doi: 10.1021/acsapm.4c02610. eCollection 2024 Dec 27.
The transition from insulator to electro-responsive has been successfully achieved by earlier studies for some inorganic materials by applying external stimuli that modify their 3D and/or electronic structures. In the case of insulating polymers, this transition is frequently accomplished by mixing them with other electroactive materials, even though a few physical treatments that induce suitable chemical modifications have also been reported. In this work, a smart approach based on the application of an electro-thermal reorientation process followed by a charged gas activation treatment has been developed for transforming insulating 3D printed polymers into electro-responsive materials. First, the developed procedure has been exhaustively investigated for 3D printed poly(lactic acid) (PLA) and subsequently has been extended to 3D printed polypropylene (PP) and poly(ethylene terephthalate glycol) (PETG) specimens. FTIR and Raman spectroscopies, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle measurements confirmed that, while the electro-thermal reorientation mainly promotes the crystallinity of the samples, the charged gas activation oxidizes the C-O bonds at the surface and consequently modifies the surface morphology and wettability. Furthermore, cyclic voltammetry assays demonstrated that treated PLA, PP, and PETG are electro-responsive, even though the electrochemical activity was much higher for oxygen-containing polymers (PLA and PETG) than for the oxygen-free one (PP). Finally, as a proof of concept, treated 3D printed PLA specimens have been used as electrochemical sensors to detect dopamine (DA), an important neurotransmitter, in a concentration interval ranging from 50 to 1000 μM. The peak associated with the oxidation from DA to dopaminoquinone and the linearity of the calibration plot, which was constructed using the anodic peak current, proved that treated PLA is not only electro-responsive but also able to electrocatalyze the oxidation of DA.
通过施加外部刺激来改变其三维结构和/或电子结构，早期的一些研究已成功实现了某些无机材料从绝缘体到电响应体的转变。对于绝缘聚合物而言，这种转变通常是通过将它们与其他电活性材料混合来实现的，不过也有报道称一些能引发适当化学改性的物理处理方法。在这项工作中，已开发出一种基于电热重新取向过程并随后进行带电气体活化处理的智能方法，用于将绝缘的3D打印聚合物转变为电响应材料。首先，已对3D打印的聚乳酸（PLA）详尽研究了所开发的程序，随后该程序已扩展至3D打印的聚丙烯（PP）和聚对苯二甲酸乙二醇酯（PETG）样品。傅里叶变换红外光谱（FTIR）和拉曼光谱、X射线衍射、X射线光电子能谱、扫描电子显微镜以及水接触角测量结果证实，虽然电热重新取向主要促进了样品的结晶度，但带电气体活化会氧化表面的C - O键，从而改变表面形态和润湿性。此外，循环伏安法分析表明，经处理的PLA、PP和PETG具有电响应性，尽管含氧化合物（PLA和PETG）的电化学活性比无氧聚合物（PP）高得多。最后，作为概念验证，经处理的3D打印PLA样品已被用作电化学传感器，用于检测浓度范围为50至1000μM的重要神经递质多巴胺（DA）。与DA氧化为多巴胺醌相关的峰以及使用阳极峰电流构建的校准曲线的线性，证明经处理的PLA不仅具有电响应性，而且能够电催化DA的氧化。
