Sharifi Javid, Rizvi Ghaus, Fayazfar Haniyeh Ramona
Eco-Friendly Circular Advanced Materials and Additive Manufacturing (ECAM) Lab, Department of Mechanical and Manufacturing Engineering, Ontario Tech University, Oshawa, ON L1G 0C5, Canada.
Department of Mechanical and Manufacturing Engineering, Ontario Tech University, Oshawa, ON L1G 0C5, Canada.
Materials (Basel). 2024 Nov 25;17(23):5782. doi: 10.3390/ma17235782.
The current study explores, for the first time, an eco-friendly solution casting method using a green solvent, ethyl acetate, to prepare feedstock/filaments from polylactic acid (PLA) biopolymer reinforced with carbon nanotubes (CNTs), followed by 3D printing and surface activation for biosensing applications. Comprehensive measurements of thermal, electrical, rheological, microstructural, and mechanical properties of developed feedstock and 3D-printed parts were performed and analyzed. Herein, adding 2 wt.% CNTs to the PLA matrix marked the electrical percolation, achieving conductivity of 8.3 × 10 S.m, thanks to the uniform distribution of CNTs within the PLA matrix facilitated by the solution casting method. Rheological assessments paralleled these findings; the addition of 2 wt.% CNTs transitioned the nanocomposite from liquid-like to a solid-like behavior with a percolated network structure, significantly elevating rheological properties compared to the composite with 1 wt.% CNTs. Mechanical evaluations of the printed samples revealed improvement in tensile strength and modulus compared to virgin PLA by a uniform distribution of 2 wt.% CNTs into PLA, with an increase of 14.5% and 10.3%, respectively. To further enhance the electrical conductivity and sensing capabilities of the developed samples, an electrochemical surface activation treatment was applied to as-printed nanocomposite samples. The field-emission scanning electron microscopy (FE-SEM) analysis confirmed that this surface activation effectively exposed the CNTs to the surface of 3D-printed parts by removing a thin layer of polymer from the surface, thereby optimizing the composite's electroconductivity performance. The findings of this study underscore the potential of the proposed eco-friendly method in developing advanced 3D-printed bio-nanocomposites based on carbon nanotubes and biopolymers, using a green solution casting and cost-effective material extrusion 3D-printing method, for electrochemical-sensing applications.
本研究首次探索了一种环保的溶液浇铸方法，该方法使用绿色溶剂乙酸乙酯，以由碳纳米管（CNT）增强的聚乳酸（PLA）生物聚合物制备原料/长丝，随后进行3D打印和表面活化以用于生物传感应用。对所开发的原料和3D打印部件的热、电、流变、微观结构和机械性能进行了全面测量和分析。在此，向PLA基体中添加2 wt.%的CNT标志着发生了电渗滤，实现了8.3×10 S.m的电导率，这得益于溶液浇铸方法促进了CNT在PLA基体内的均匀分布。流变学评估与这些发现一致；添加2 wt.%的CNT使纳米复合材料从类液体行为转变为具有渗滤网络结构的类固体行为，与含有1 wt.% CNT的复合材料相比，显著提高了流变性能。对打印样品的机械评估表明，通过将2 wt.%的CNT均匀分布到PLA中，与纯PLA相比，拉伸强度和模量有所提高，分别增加了14.5%和10.3%。为了进一步提高所开发样品的电导率和传感能力，对打印后的纳米复合材料样品进行了电化学表面活化处理。场发射扫描电子显微镜（FE-SEM）分析证实，这种表面活化通过从表面去除一层薄聚合物有效地使CNT暴露在3D打印部件的表面，从而优化了复合材料的导电性能。本研究结果强调了所提出的环保方法在基于碳纳米管和生物聚合物开发先进的3D打印生物纳米复合材料方面的潜力，该方法采用绿色溶液浇铸和具有成本效益的材料挤出3D打印方法，用于电化学传感应用。
