Surfactant-assisted regulation of polydivinylbenzene nanofibers morphology

In this study, we described a simple surfactant-assisted approach for synthesizing polydivinylbenzene (PDVB) nanofibers with different morphologies and dimensions. By adding different amounts of specific surfactant (1,2-epoxyalkane, fatty acids, and fatty alcohols) during the polymerization of divinylbenzene (DVB), the shape or size of PDVB nanofibers can be changed, for example the diameter has been reduced to 50–100 nm and helical nanofibers has been obtained. This kind of PDVB nanofibers have widespread potential application in nanomaterials and nanofibers with different requirements.     

Electrospinning Janus Nanofibrous Membrane for Unidirectional Liquid Penetration and Its Applications

Janus membrane with opposite wettability on its two sides has witnessed an explosion of interest in the field of liquid spontaneous and directional transport for their promising prospect. The advances in fabrication technology and natural bionics have brought remarkable progress for the development of Janus mate-rials. Among the exciting progress, the micro/nanofabrication technique of electrospinning shows advantages in constructing thin porous fibrous membrane materials with controllable surface wettabi-lity and hierarchical structures. Here, a brief review of bioinspired Janus membrane for unidirectional liquid penetration fabricated by electrospinning is presented, and the underlying scientific mechanism is discussed with an emphasis on the materials design involving asymmetric surface wettability and micro-topology structure. An overview of recent emerging applications is also reviewed, with special attentions to liquid separation, water collection, distillation, and smart textile, etc. As researchers keep to develop more efficient strategies on designing new Janus membrane with higher performances, it has become increasingly important to understand the mechanism of liquid moving dynamics at the asymmetric interface in order to better recognize the scientific limitations currently hindering the field development. At last, the challenges currently faced and possible strategies on developing new Janus membranes for optimization and engineering in the future are proposed.     

Promotion of Neurite Outgrowth and Extension Using Injectable Welded Nanofibers

We report a general strategy to develop injectable welded nanofibers to facilitate the outgrowth and extension of neurites. In this case, nonwoven mats of uniaxially aligned poly(caprolactone)(PCL) nanofibers were firstly cut into several small pieces with fixed fiber lengths of 25, 50 and 100 μm, respectively, using a cryotome. A tissuelyser was employed to homogenize and disperse the short nanofibers to a homogeneous suspension. By tuning treatment duration from 100 s to 400 s, the temperature of the suspension was brought close to the melting point of PCL. As such, the short nanofibers were welded at their cross points while the fibers far away from the cross points remain the original structures. We showed that the viability of neuroblastoma SH-SY5Y cells and their neurite outgrowth and extension were enhanced with the use of such welded short nanofibers. Taken together, this study provides a simple way to generate injectable welded nanofibers, holding potential in affecting neurite outgrowth and extension for nerve repair, in particular, in the central nervous system.     

PVA/GA/β-CD纳米纤维的制备及染料吸附性能

利用静电纺丝技术,以六氟异丙醇(HFIP)和水为溶剂,制备了环糊精(β-CD)含量为70%(质量分数)的聚乙烯醇(PVA)/β-CD纳米纤维,并经戊二醛(GA)交联处理得到了可用于染料吸附的PVA/GA/β-CD纳米纤维.通过红外光谱和扫描电子显微镜研究了交联反应前后纳米纤维组成和形貌的变化;考察了PVA/GA/β-CD纳米纤维对7种水溶性染料的吸附性能.结果表明,PVA/GA/β-CD纳米纤维对孔雀石绿、甲基紫和刚果红的吸附效果较好,最大吸附量分别为124.71,121.14和127.39 mg/g,4次吸附-解吸附循环后,染料去除率仍保持80%左右,在染料废水处理中具有良好的应用前景.     

原位红外光谱法研究电纺聚酰胺酸纳米纤维膜热亚胺化过程

以均苯二酐和二苯醚二胺为原料合成聚酰胺酸溶液,通过静电纺丝法制得聚酰胺酸纳米纤维膜.利用原位红外技术研究亚胺化进程,并以优化的条件制得聚酰亚胺纳米纤维膜.研究结果表明,当升温速率为2℃/min时,在350℃可实现100%亚胺化;升温速率过快,纳米纤维膜的亚胺化程度较低;采用快速-慢速相结合的升温方法,则可以有效地提高亚胺化效率.     

以四肽自组装体为模板制备手性3-氨基苯酚甲醛树脂纳米纤维

采用经典的固相合成法制备了一对烷基取代丙氨酸四肽衍生物对映体,研究了其在不同溶剂中的成胶行为,并以其在甲醇中形成的超分子自组装体为模板,利用溶胶-凝胶法制备了单手螺旋3-氨基苯酚甲醛树脂纳米纤维.利用扫描电子显微镜和透射电子显微镜观察超分子自组装体及3-氨基苯酚甲醛树脂的螺旋形貌,并利用圆二色谱研究其光学性质.研究发现,3-氨基苯酚甲醛树脂纳米纤维既具有纳米尺度的手性,又具有分子尺度的手性.手性从小分子形成的自组装体传递到高分子树脂中.     

同轴静电纺丝法在纳米中空Ti02纤维中填充Ag的应用

以聚乙烯吡咯烷酮(PVP)溶胶,钛酸四正丁酯和PVP溶胶,银颗粒为前驱体,以共轴静电纺丝法制备了银填充的TiO2中空纳米纤维.将双组分纤维在200℃下热处理去除乙醇与表面吸附水后,继而在空气气氛中焙烧至600℃.可以得到在内表面上沉积银颗粒的TiO2纳米管,银颗粒的直径为5-40 nm,TiO2纳米管的外径150-300 nm.管臂厚10-20 nm.用红外吸收光谱(IR)、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等测试手段对超细纤维进行了表征.中空纤维的直径和管壁可以通过改变电纺参数来调节.与Ag-TiO2纳米纤维、TiO2纳米中空纤维、TiO2纳米纤维及TiO2纳米粉体相比较,Ag颗粒填充的TiO2纳米中空纤维在光分解亚甲基蓝上表现出了更好的光催化性能.     

Fabrication of Poly（4-vinylpyridine） Nanofiber and Fluorescent Poly（4-vinylpyridine）/Porphyrin Nanofiber by Electrospinning

Poly（4-vinylpyridine）（P4-VP） nanofiber and fluoresent poly（4-vinylpyridine）/porphyrin（P4-VP/TPPA） nanofiber were respectively prepared by electrospinning. The effect of the concentration of P4-VP/dimethylformamide （DMF） electrospinning solutions on the morphology of P4-VP nanofiber was investigated and it was found that the average diameter of the nanofiber of P4-VP/DMF increased with the increase of the concentration of the spinning solution. After the addition of TPPA to the P4-VP/DMF spinning solution, the diameter of P4-VP/TPPA nanofiber became even due to the increase of the conductivity of the P4-VP/DMF-TPPA solution. The photoluminescent（PL） spectral analysis indicates that the emission peak position of P4-VP/TPPA nanofiber is almost the same as that of pure TPPA at about 650 nm without peak shift, and when it was stored for 20 days, the emission peak of P4-VP/TPPA nanofiber is also at 650 nm, indicating that the fluorescent property of P4-VP/TPPA nanofiber is stable. Fourier-transform iufrared（FTIR） spectrum confirms the chemical composition of the resulting P4-VP/TPPA composite nanofiber.     

Electrospun aligned nanofibers: A review

Electrospinning (e-spinning) is famous for the construction and production of ultrafine and continuous micro-/nanofibers. Then, the alignment of electrospun (e-spun) nanofibers becomes one of the most valuable research topics. Because aligned fibers have more advantages over random fibers, such as better mechanical properties, faster charge transport, more regular spatial structure, etc. This review summarizes various electrospinning techniques of fabricating aligned e-spun nanofibers, such as early conventional methods, near-field e-spinning, and three-dimensional (3D) printing e-spinning. Among them, four auxiliary preparation methods (e.g., auxiliary solid template, auxiliary liquid, auxiliary electromagnetic field and auxiliary airflow), two collection modes (static and dynamic collection), and the controllability of near-field e-spinning and 3D printing e-spinning are highlighted. The representative applications depending on aligned nanofibers are classified and briefly introduced, emphasizing in the fields of 1D applications (e.g., field-effect transistor, nanochannel and guidance carrier), 2D applications (e.g., platform for gas detection, filter, and electrode materials storage), and 3D applications (e.g., bioengineering, supercapacitor, and nanogenerator). At last, the challenges and prospects are addressed.     

聚对二甲苯纳米纤维阵列的CVD液晶模板法制备及降解性能

聚对二甲苯(PPX)具有优异的生物相容性和化学稳定性, 将其构建成仿细胞外基质结构的可降解纳米纤维在生物工程领域具有重要意义. 本文采用化学气相沉积(CVD)法, 以向列型热致液晶E7为模板, 以4-羟甲基-对二甲苯二聚体(PCP-CH₂OH)为聚-(4-羟甲基-对二甲苯)(PPX-CH₂OH)的前驱体, 通过在其分子链上引入 5,6-苯并-2-亚甲基-1,3-二氧杂环庚烷(BMDO)链段制备BMDO/PPX-CH₂OH共聚物纳米纤维阵列, 探讨了共聚物纳米纤维阵列形貌的影响因素, 分析得到了制备共聚物纳米纤维阵列的最佳反应条件, 并研究了BMDO/PPX-CH₂OH共聚物纳米纤维阵列的生物降解性能. 研究表明, 在液晶模板作用下, 通过CVD法成功地使PCP-CH₂OH与BMDO共聚, 并得到了BMDO/PPX-CH₂OH共聚物纳米纤维阵列; 其形貌主要受样品台的温度和沉积速率的影响, 而单体质量比影响较小; 经优化后CVD最佳条件为: 样品台温度-10 ℃, 沉积速率约为0.01 nm/s, 单体质量比为10∶1; 共聚物在37 ℃的0.1 mol/L Na₂CO₃/0.1 mol/L NaHCO₃的缓冲溶液体系下可有效降解, 当降解时间超过23 d后, 纳米纤维阵列中的酯基可完全分解; 当降解时间超过30 d时, 纳米纤维阵列基本降解完全, 总体呈碎片状.