Microwave Physics and Dielectrics Department, Physics Research Institute, National Research Centre, Giza, Egypt.
Solid State Physics Department, Physics Research Institute, National Research Centre, Giza, Egypt.
Sci Rep. 2024 Jul 28;14(1):17343. doi: 10.1038/s41598-024-67423-w.
In recent years, academic and industrial research has focused on using agro-waste for energy and new material production to promote sustainable development and lessen environmental issues. In this study, new nanocomposites based on polyvinyl alcohol (PVA)-Starch using two affordable agricultural wastes, Citrus limon peels (LP) and Citrullus colocynthis (Cc) shells and seeds powders with different concentrations (2, 5, 10, and 15 wt%) as bio-fillers were prepared. The nanocomposites were characterized by Dielectric Spectroscopy, Fourier-Transform Infrared (FTIR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and water swelling ratio. The antimicrobial properties of the nanocomposites against Escherichia coli, Staphylococcus aureus, and Candida albicans were examined to investigate the possibility of using such composites in biomedical applications. Additionally, the biocompatibility of the composites on human normal fibroblast cell lines (HFB4) was tested using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The results demonstrate that the filler type and concentration strongly affect the film's properties. The permittivity ε', dielectric loss ε″ and conductivity σ increased by increasing filler content but still in the insulators range that recommend such composites to be used in the insulation purposes. Both bio fillers control the water uptake, and the samples filled with LP were more water resistant. The polyvinyl alcohol/starch incorporated with 5 wt% LP and Cc have antimicrobial effects against all the tested microorganisms. Increasing the filler content has a negative impact on cell viability.
近年来，学术和工业研究集中于利用农业废弃物生产能源和新材料，以促进可持续发展并减少环境问题。在这项研究中，使用两种经济实惠的农业废弃物——柠檬皮（LP）和西瓜皮和种子粉末，制备了基于聚乙烯醇（PVA）-淀粉的新型纳米复合材料，浓度分别为 2、5、10 和 15wt%。纳米复合材料的特性通过介电谱、傅里叶变换红外（FTIR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和水膨胀率进行了表征。测试了纳米复合材料对大肠杆菌、金黄色葡萄球菌和白色念珠菌的抗菌性能，以研究将此类复合材料用于生物医学应用的可能性。此外，还使用 MTT（3-[4,5-二甲基噻唑-2-基]-2,5-二苯基四氮唑溴化物）测定法测试了复合材料对人正常成纤维细胞系（HFB4）的生物相容性。结果表明，填充剂类型和浓度强烈影响薄膜的性能。介电常数 ε'、介电损耗 ε″和电导率 σ随填充剂含量的增加而增加，但仍处于绝缘体范围内，建议此类复合材料用于绝缘目的。两种生物填料均控制水的吸收，填充 LP 的样品更能抵抗水的渗透。聚乙烯醇/淀粉中添加 5wt%LP 和 Cc 对所有测试的微生物均具有抗菌作用。增加填充剂含量会对细胞活力产生负面影响。
