Kimiaei Erfan, Farooq Muhammad, Szymoniak Paulina, Ahmadi Shayan, Babaeipour Sahar, Schönhals Andreas, Österberg Monika
Department of Bioproducts and Biosystems, School of Chemical Engineering, Aalto University, PO Box 16300, FIN-00076 Aalto, Espoo, Finland.
Bundesanstalt für Materialforschung und-prüfung (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
J Colloid Interface Sci. 2025 Feb;679(Pt B):263-275. doi: 10.1016/j.jcis.2024.10.083. Epub 2024 Oct 18.
Advancing nanocomposites requires a deep understanding and careful design of nanoscale interfaces, as interfacial interactions and adhesion significantly influence the physical and mechanical properties of these materials. This study demonstrates the effectiveness of lignin nanoparticles (LNPs) as interfacial compatibilizer between hydrophilic cellulose nanofibrils (CNF) and a hydrophobic polyester, polycaprolactone (PCL). In this context, we conducted a detailed analysis of surface-to-bulk interactions in both wet and dry conditions using advanced techniques such as quartz crystal microbalance with dissipation (QCM-D), atomic force microscopy (AFM), water contact angle (WCA) measurements, broadband dielectric spectroscopy (BDS), and inverse gas chromatography (IGC). QCM-D was employed to quantify the adsorption behavior of LNPs on CNF and PCL surfaces, demonstrating LNPs' capability to interact with both hydrophilic and hydrophobic phases, thereby enhancing composite material properties. LNPs showed extensive adsorption on a CNF model film (1186 ± 178 ng.cm) and a lower but still significant adsorption on a PCL model film (270 ± 64 ng.cm). In contrast, CNF adsorption on a PCL model film was the lowest, with a sensed mass of only 136 ± 35 ng.cm. These findings were further supported by comparing the morphology and wettability of the films before and after adsorption, using AFM and WCA analyses. Then, to gain insights into the molecular-level interactions and molecular mobility within the composite in dry state, BDS was employed. The BDS results showed that LNPs improved the dispersion of PCL within the CNF network. To further investigate the impact of LNPs on the composites' interfacial properties, IGC was employed. This analysis showed that the composite films containing LNPs exhibited lower surface energy compared to those composed of only CNF and PCL. The presence of LNPs likely reduced the availability of surface hydroxyl groups, thus modifying the physicochemical properties of the interface. These changes were particularly evident in the heterogeneity of the surface energy profile, indicating that LNPs significantly altered the interfacial characteristics of the composite materials. Overall, these findings emphasize the necessity to control the interfaces between components for next-generation nanocomposite materials across diverse applications.
推进纳米复合材料的发展需要对纳米级界面有深入的理解和精心的设计，因为界面相互作用和粘附力会显著影响这些材料的物理和机械性能。本研究证明了木质素纳米颗粒（LNPs）作为亲水性纤维素纳米纤维（CNF）和疏水性聚酯聚己内酯（PCL）之间界面增容剂的有效性。在此背景下，我们使用了诸如带耗散的石英晶体微天平（QCM-D）、原子力显微镜（AFM）、水接触角（WCA）测量、宽带介电谱（BDS）和反相气相色谱（IGC）等先进技术，对湿态和干态下的表面到本体的相互作用进行了详细分析。QCM-D用于量化LNPs在CNF和PCL表面的吸附行为，证明了LNPs与亲水性和疏水性相相互作用的能力，从而增强了复合材料的性能。LNPs在CNF模型膜上有大量吸附（1186±178 ng·cm），在PCL模型膜上的吸附量较低但仍很显著（270±64 ng·cm）。相比之下，CNF在PCL模型膜上的吸附量最低，检测到的质量仅为136±35 ng·cm。通过使用AFM和WCA分析比较吸附前后膜的形态和润湿性，进一步支持了这些发现。然后，为了深入了解干燥状态下复合材料内部分子水平的相互作用和分子流动性，采用了BDS。BDS结果表明，LNPs改善了PCL在CNF网络中的分散性。为了进一步研究LNPs对复合材料界面性能的影响，采用了IGC。该分析表明，与仅由CNF和PCL组成的复合膜相比，含有LNPs的复合膜表现出更低的表面能。LNPs的存在可能降低了表面羟基的可用性，从而改变了界面的物理化学性质。这些变化在表面能分布的不均匀性中尤为明显，表明LNPs显著改变了复合材料的界面特性。总体而言，这些发现强调了在各种应用中控制下一代纳米复合材料各组分之间界面的必要性。
