标题: 超分子型高分子应用于电纺奈米纤维
Supramolecular Polymers for Application in Electrospun Nanofibers
作者: 王业升
Wang, Yeh-Sheng
张丰志
孙建文
Chang, Feng-Chih
Sun, Kien-Wen
应用化学系硕博士班
关键字: 超分子聚合物;电纺丝;奈米纤维;氢键;Supramolecular polymer;Electrospinning;Nanofiber;Hydrogen bonding
公开日期: 2013
摘要: 本论文中以开发超分子型高分子材料应用于电纺奈米纤维,内容分为四大主题:
1. 尿嘧啶官能化高分子的仿生光交联奈米纤维
在本研究中,我们利用电纺技术制备具核硷基官能化及光致交联的poly[1-(4-vinylbenzyl uracil)](PVBU)奈米纤维。高分子量的PVBU(Mn >250 550 g/mol)具有高的热稳定性和足够的分子链缠结度,以利制备均匀且无珠状小球的纤维。这些尿嘧啶官能化的奈米纤维可透过照射254奈米波长的紫外光进一步光交联。在浸渍于溶剂N,N-dimethylacetamide后,原始PVBU纤维溶解,而交联的PVBU纤维保持其形状,因此,交联PVBU奈米纤维表现出良好的尺寸稳定性和提高的耐溶剂性。
2. 仿生超分子纤维对汞离子的吸附
以尿嘧啶官能化高分子poly[1-(4-vinylbenzyl uracil)](PVBU)为基础的新光交联型奈米纤维,利用静电纺丝技术制备出。PVBU奈米纤维藉由曝照于254奈米波长的紫外光可转换成共价网络键结的奈米纤维。PVBU奈米纤维能够区分并选择性地从含其它金属离子的水溶液之中除去汞离子(Hg2+)。该PVBU奈米纤维的最大汞离子的吸附量为543.9毫克/克,它比环状imide衍生物的吸附量显着更高。 由于汞离子吸附的增加使之侦测极限低于1ppm,这在汞离子侦测中很少能达到。此外,用1.0M HCl还原处理,PVBU纤维可以连续重复使用10个循环。这种新材料可同时侦测和分离汞离子在环境和工业领域中具有显着的潜力。这种新材料具有显着的潜力在同时侦测和分离汞离子于环境和工业领域之中。
3. 共轭型电纺奈米纤维的形貌与光学物理性质于氢键作用力下的影响
Poly(3-thiophene-triazole-diaminopyridin)( PTDAP )的发光奈米纤维经由混合具互补氢键键结点之主体高分子poly[1-(4-vinylbenzyl uracil)]( PVBU )以及对照的主体高分子聚苯乙烯( PS )成功地电纺制备出。从1-50 %(重量)混合比例电纺出的PTDAP / PVBU纤维其直径为300-1270奈米与PTDAP / PS纤维相比展现出均匀的形貌和萤光性。当PTDAP的混合比例增加,PTDAP/PS纤维中珠状结构的纤维和珠状小球增加,这表示和PVBU相比PTDAP与PS有较差的相容性而导致PTDAP的聚集,且在旋转涂布的薄膜也获得类似的结果。此外,在相同PTDAP的混合比例下PTDAP / PVBU纤维的放光波峰比PTDAP /PS纤维更加蓝移,这表示强的氢键作用有利于PTDAP与PVBU沿纤维轴延伸从而防止PTDAP的聚集,因此移到更高能量放射。
4. 多层奈米碳管分散于氢键系统中的电纺奈米复合纤维之制备与特性
含有共轭高分子poly(3-thiophene-triazole-diaminopyridin)( PTDAP )和多层奈米碳管(MWCNTs)的奈米复合纤维藉由与两个主体高分子,poly[1-(4-vinylbenzyl uracil)]( PVBU )具有氢键合性官能团和对照的聚苯乙烯(PS)电纺制备出并研究奈米碳管在纤维中的分散与聚集。导电度的结果显示PVBU / PTDAP / MWCNT纤维比PS / PTDAP / MWCNT纤维能形成低电阻的一个更好的电通路,这表示PVBU主体和PTDAP主体之间的氢键相互作用确实帮助多层碳奈米碳管在纤维中的分散。透射电子显微镜显示,多层奈米碳管在PVBU / PTDAP主体之中是高度沿纤维轴的方向。即使高浓度的多层奈米碳管在PVBU / PTDAP / MWCNT纤维中一样能分散很好,这可以归因于PTDAP能藉由π-π相互作用连结无官能化的多层奈米碳管表面,防止多层奈米碳管聚集,同时PVBU主体提供了与PTDAP的氢键作用力,分散了脱附的多层奈米碳管在电纺过程能整齐排列于高分子主体中。这项研究不仅改善了奈米碳管在电纺奈米纤维中的分散性,同时也示范藉由导入氢键作用力设计具有延展和高度对齐多层奈米碳管的复合奈米纤维之可能性。
In this study, we focus on four major subjects which based on supramolecular polymers for application in electrospun nanofibers.
1. Bioinspired Photo-Cross-Linked Nanofibers from Uracil-Functionalized Polymers
In this study, we used electrospinning to fabricate nucleobase functionalized and photo-cross-linkable poly[1-(4-vinylbenzyl uracil)] (PVBU) nanofibers. PVBU of high-molecular-weight (Mn > 250 550 g/mol) possessed a high thermal stability and sufficient chain entanglement to produce uniform fibers without forming beads. These uracil-functionalized nanofibers were further photo-cross-linked through exposure to UV light at a wavelength of 254 nm. After immersing in N,N-dimethylacetamide, the pristine PVBU fibers dissolved, while the cross-linked PVBU fibers maintained their shape; thus, the cross-linked PVBU nanofibers exhibited good dimensional stability and improved solvent resistance.
2. Bioinspired Supramolecular Fibers for Mercury Ion Adsorption
A novel photo-cross-linkable nanofiber based on a uracil-functionalized polymer, poly[1-(4-vinylbenzyl uracil)] (PVBU), was prepared using the electrospinning technique. This PVBU nanofiber can be converted into a covalent network nanofiber through exposure to UV light at a wavelength of 254 nm. This PVBU nanofiber is able to distinguish and selectively remove mercury ions (Hg2+) from other metal ions in aqueous solution. The maximum Hg2+ adsorption capacity of the PVBU nanofiber is 543.9 mg g-1, which is significantly higher than that of cyclic imide derivatives. The improved adsorption of Hg2+ allows a detection limit of less than 1 ppm, which has rarely been achieved for Hg2+ sensing. Furthermore, the PVBU fiber can be reused for 10 consecutive cycles using 1.0 M HCl treatment. This new material has significant potential for the simultaneous detection and separation of Hg2+ in environmental and industrial fields.

3. The Influence of Hydrogen Bonding Interaction on Morphology and Photophysical Properties of Conjugated Electrospun Nanofibers
Light-emitting nanofibers of poly(3-thiophene-triazole-diaminopyridin) (PTDAP) were successfully electrospun through binary blends of two matrix polymers from poly1-(4-vinylbenzyl uracil) (PVBU) which possessed complementary hydrogen bonding sites and compared polystyrene (PS). PTDAP/PVBU blend fibers with diameters of 300-1270 nm electrospun from 1-50 wt% blend ratios show the uniform morphologies and fluorescence in comparison with PTDAP/PS blend fibers. The increases of beaded structure fibers and beads in PTDAP/PS blend fibers as the increase of PTDAP blend ratio indicates that PTDAP has worse misibility with PS than PVBU inducing the aggregation of PTDAP and a similar result is obtained in the spin-coated films. In addition, the emission peaks of PTDAP/PVBU fibers were more blue-shifted than those of PTDAP/PS fibers at the same PTDAP blend ratio which indicates that the strong hydrogen bonding facilitates PTDAP more extending along the fiber axis with PVBU which prevents the aggregation of PTDAP thereby shifting the emission to higher energies.

4. Fabrication and Characterization of Multiwalled Carbon Nanotubes Dispersion to Hydrogen-Bonding System of Electrospun Composite Nanofibers
Composite nanofibers containing conjugated polymer, poly(3-thiophene-triazole-diaminopyridin) (PTDAP), and multiwalled carbon nanotubes (MWCNTs) were electrospun with two polymer matrices, poly1-(4-vinylbenzyl uracil) (PVBU) possessing hydrogen bonding functional group and compared polystyrene (PS) and study the dispersion and arrangement of nanotubes in the fibers. The conductivity result showed that PVBU/PTDAP/MWCNT fiber can form a better charged pathway of low resistance than PS/PTDAP/MWCNT fiber, indicating that the hydrogen bonding interaction between PVBU matrix and PTDAP did facilitate the dispersion of MWCNTs in the fibers. Transmission electron microscopy showed that the MWCNTs were highly oriented along the fiber axis in the PVBU/PTDAP matrix. MWCNTs are well dispersed in PVBU/PTDAP/MWCNT fiber even at high concentration which can be attributed that PTDAP can bind to the surface of non-functionalized MWCNTs through π–π interactions, preventing MWCNTs from aggregating, while PVBU matrix provide hydrogen-bonding forces with PTDAP, dispersing the de-bundled MWCNTs aligning in the polymer matrix during electrospinning process. This study not only improves the nanotube dispersion in the electrospun nanofibers but also demonstrates a possibility to design a composite nanofiber with extended and highly aligned MWCNTs by introducing hydrogen bonding forces.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079725830
http://hdl.handle.net/11536/74240
显示于类别:Thesis