Alotaibi Rajeh, Alawad Majed O, Khalil Khaled D, Al-Rafai Hana, Bashal Ali H, Alotaibi Abdullah A, Zaidi B
Department of Chemistry, College of Science, King Saud University, P.O Box 145111, Riyadh, Saudi Arabia.
Center of Excellence for Nanomaterials for Clean Energy Applications, King Abdulaziz City for Science and Technology (KACST), Riyadh 12354, Saudi Arabia.
Int J Biol Macromol. 2025 May;305(Pt 1):141132. doi: 10.1016/j.ijbiomac.2025.141132. Epub 2025 Feb 16.
A composite of carboxymethyl cellulose (CMC) and cerium oxide (CeO₂) nanoparticles was synthesized using the solution cast method with CeO₂ concentrations of 5 %, 10 %, and 15 %. Surface topography, dispersion, and elemental composition were analyzed via SEM and EDX, while impedance spectroscopy was performed at temperatures of 298-373 K over a frequency range of 50 Hz-1.2 MHz. The study revealed that temperature and CeO₂ concentration significantly influence the composite properties. D.C. conductance increased with temperature and CeO₂ content, rising from 2.8 × 10 S for pure CMC to 58.2 × 10 S at 15 % CeO₂. Activation energy decreased from 220.05 meV (pure CMC) to 69.54 meV (15 % CeO₂). At 10 % CeO₂, the conduction mechanism was identified as non-overlapping small polaron due to homogenous dispersion. Higher CeO₂ concentrations led to nanoparticle aggregation, affecting the dielectric constant and increasing interface-induced polarization. Dielectric loss anomalies and modulus spectra changes at high CeO₂ content were linked to disrupted CMC molecular structure. Ionic conduction dominated below 348 K. Computational studies (DFT and MD simulations) confirmed increased binding energy between components, from 420.3 eV (5 % CeO₂) to 1226.3 eV (15 % CeO₂), highlighting temperature and concentration effects on interactions.
采用溶液浇铸法合成了羧甲基纤维素（CMC）与氧化铈（CeO₂）纳米颗粒的复合材料，其中CeO₂的浓度分别为5%、10%和15%。通过扫描电子显微镜（SEM）和能谱仪（EDX）分析了表面形貌、分散情况和元素组成，同时在298 - 373 K的温度范围内、50 Hz - 1.2 MHz的频率范围内进行了阻抗谱测量。研究表明，温度和CeO₂浓度对复合材料性能有显著影响。直流电导随温度和CeO₂含量的增加而增加，从纯CMC的2.8×10⁻⁶ S增加到15% CeO₂时的58.2×10⁻⁶ S。活化能从220.05 meV（纯CMC）降至69.54 meV（15% CeO₂）。在10% CeO₂时，由于均匀分散，导电机制被确定为非重叠小极化子。较高的CeO₂浓度导致纳米颗粒聚集，影响介电常数并增加界面诱导极化。高CeO₂含量下的介电损耗异常和模量谱变化与CMC分子结构破坏有关。在348 K以下，离子传导占主导。计算研究（密度泛函理论和分子动力学模拟）证实了各组分之间的结合能增加，从420.3 eV（5% CeO₂）增加到1226.3 eV（15% CeO₂），突出了温度和浓度对相互作用的影响。
