定向导水纸尿裤面层材料的制备及其性能

以聚乳酸(polylactic acid,PLA)非织造布为基布,采用多巴胺亲水改性和静电喷雾技术制备定向导水纸尿裤面层材料.结合扫描电子显微镜和傅里叶变换红外光谱对纸尿裤面层材料的结构和形貌进行表征,并测试材料的水接触角、芯吸高度、耐水压和液态水分管理能力,以研究多巴胺亲水改性和静电喷雾时间对材料定向导水性能的影响....     

Controllable Fabrication of Spider-Web-Like Structured Anaphe Panda Regenerated Silk Nanofibers/Nets via Electrospinning/Netting

An Anaphe panda silk nanofibers / nets( NFN) membrane with attractive structures consisting of common electrospun nanofibers and two-dimensional( 2D) spider-web-like structured nano-nets were successfully fabricated via electrospinning / netting technology. The unique structures of NFN membranes such as extremely small diameter( 20 nm),high porosity,large specific surface area. and biocompatibility make this Anaphe panda silk NFN membrane a promising candidate for biomedical applications. In the present study, field emission scanning electron microscopy( FESEM) was used to investigate the influence of polymer solution and humidity on nano-nets coverage and morphology. The FE-SEM images revealed that nano-net coverage area increased with increase in concentration of solution while lowering the humidity increased the nano-nets formation. Moreover,the mechanical properties of the membrane were also tested and the result showed that the silk NFN membrane displayed a breaking stress of 3. 7 MPa and breaking strain of 13. 8%. For further structural elucidation, Fourier transform infrared spectroscopy( FT-IR) was used to analyze the structural conformation changes from random coil to β-sheet in the NFN membrane which was an important factor effecting the usability of membrane. Thus,the results above confirmed the feasibility of Anaphe panda NFN structures applicability in cell tissue culture and other biomedical applications.     

钙对NaCl胁迫下百合花粉萌发、脯氨酸含量和SOD活性的影响

以百合花粉为实验材料,采用花粉液体培养法探讨了植物信号物质钙在NaCl抑制百合花粉萌发中的作用.结果表明:NaCl对百合花粉萌发有抑制作用,抑制程度随培养基中NaCl浓度的增大而加强,甚至完全抑制花粉萌发,NaCl显著抑制百合花粉萌发的浓度为25 mmol/L,此时花粉萌发率下降到32.3%,仅为对照的52.5%.Ca(NO3)2能够部分缓解NaCl对百合花粉萌发的抑制作用,其缓解作用的浓度为1.5~3mmol/L,其中以2 mmol/L对NaCl胁迫的缓解效果最佳,花粉萌发率达到最大,为50.7%.超过此浓度范围后,缓解作用下降,甚至出现抑制作用.NaCl胁迫条件下,外源钙显著降低盐胁迫下萌发花粉的脯氨酸含量而增加SOD活性.     

PAN/CNT复合纳米纤维膜的制备及其红外辐射特性

采用静电纺丝技术制备了聚丙烯腈/碳纳米管(PAN/CNT)复合纳米纤维膜,利用扫描电子显微镜、透射电子显微镜、傅里叶变换红外光谱仪和拉曼光谱仪对CNT质量分数不同的PAN/CNT复合纳米纤维膜进行了表征和分析,并利用紫外可见近红外光谱仪和配备有积分球的傅里叶变换红外光谱仪对PAN/CNT复合纳米纤维膜在可见光和红外光段的辐射特性进行了测试和考察。结果表明:静电纺丝技术可制备CNT分布均匀的PAN/CNT复合纳米纤维膜;相较于纯PAN纳米纤维膜,PAN/CNT复合纳米纤维膜的可见光谱和红外光谱吸收率显著增强,且随着CNT质量分数的增加,复合纳米纤维膜的红外光谱吸收率呈增大趋势。研究结果为PAN/CNT复合纳米纤维膜在太阳能光热转化和中红外辐射领域的进一步应用提供了理论依据。     

烷烃修饰SiO_2纳米颗粒油/水界面吸附特性的分子动力学模拟

采用分子动力学方法对比研究烷烃修饰前后SiO2纳米颗粒在油/水界面的吸附组装行为,分析其密度分布、界面层厚度、界面张力等参量。结果表明:烷烃修饰后纳米颗粒疏水性增强,能自发地快速向油/水界面扩散运移,并在界面形成致密的组装单层膜;烷烃修饰纳米颗粒在油/水界面的吸附能够有效降低界面张力,提高水相对油相的携带能力。