聚乳酸/壳聚糖-海藻酸复合纳米纤维膜材料的结构与性能研究

通过聚乳酸与壳聚糖混合静电纺丝并用EDC/NHS对纤维在水溶液中与海藻酸接枝改性,制备了聚乳酸复合纳米纤维膜PLA/CS-Al。微观形貌分析表明PLA/CS-Al具有光滑平直的纤维形貌(直径为98. 7nm)。热重分析表明该方式引入壳聚糖和海藻酸会小幅度降低纤维膜材料的热稳定性。静态水接触角和蛋白质吸附测试显示PLA/CS-Al比纯PLA和PLA/CS纤维膜具有更强的亲水性,静态水接触角为82°。体外降解实验表明PLA/CS-Al具有比纯PLA纤维膜材料更好的降解速率,8周后的体外降解率达14. 35%。     

聚乳酸电纺纤维膜的油水分离性能

采用静电纺丝法,制备了聚乳酸(PLA)电纺纤维膜。通过扫描电子显微镜、接触角测试仪等表征了PLA电纺纤维膜的纤维结构和水接触角,并研究了其油水分离性能。结果表明PLA可纺性好,电纺纤维膜为由光滑的微纤维组成的三维多孔网络结构,纤维直径1～2μm,纤维膜孔径为3～10μm且分布较均匀。PLA电纺纤维膜的水接触角可达136°以上,具有良好的疏水性。PLA电纺纤维膜对油水混合物的分离效率可达98.3%以上,最大分离通量约15 000 L·m^-2·h^-1。     

高通量rGO微球@PVDF纳米纤维复合膜的制备及其油水分离性能研究

采用静电纺丝法制备了聚偏氟乙烯(PVDF)纳米纤维膜,并采用共混纺丝法和真空抽滤两种方式将还原氧化石墨烯微球(rGO)负载于其上,获得高通量rGO微球@PVDF纳米纤维复合油水分离膜。通过调整静电纺丝过程参数(如推注速率和电场强度等)和纺丝液配方,对PVDF纳米纤维膜结构进行优化,并采用不同的rGO微球负载量、负载方式、黏结剂含量来提高纳米纤维膜的表面粗糙度和疏水性。利用扫描电子显微镜和接触角测试对纤维膜的表面形貌和亲疏水性进行表征,并通过二氯甲烷-水体系进行油水分离实验,测试了不同配方下杂化膜的重力驱动油水分离性能。结果表明,当静电纺丝溶液中PVDF含量为14%时,以1 mL·h^-1的推注速率,在15 kV下制得的PVDF纳米纤维膜,并将1%PVDF溶液、3 mg rGO微球(与黏结剂中有效成分PVDF质量比为3∶1)和溶剂组成的铸膜液抽滤在膜表面,复合膜表面水接触角为130.9°,其油水分离过程中的有机溶剂透过通量可达5 641.3 L·h^-1·m^-2,水相的截留率为99.28%。     

壳聚糖/聚乙烯醇/壳寡糖抑菌纳米纤维膜的制备和性能研究

以壳聚糖（CS）为基材，使用静电纺丝的方法制备了搭载壳寡糖（CHOS）的CS/聚乙烯醇（PVA）/CHOS纳米纤维膜，并对纳米纤维膜的微观形貌、结构、抑菌性、亲水性以及溶解性能进行了研究。研究发现：CS/PVA/CHOS纳米纤维膜具备均匀密致的微观形貌；FT-IR测试表明，CHOS以物理混合的形式分散在CS/PVA/CHOS纳米纤维膜中；XRD测试表明，CHOS的加入改变了纳米纤维膜的结晶性，促进了各组分之间的相容性；水接触角测试表明纳米纤维膜具备良好的亲水性，在m（CS）：m（PVA）：m（CHOS）=20：80：10时，CS/PVA/CHOS纳米纤维膜的接触角相比于m（CS）：m（PVA）=20：80的CS/PVA纳米纤维膜由59.8°下降到37.5°；抑菌性能和溶解性能测试表明，m（CS）：m（PVA）：m（CHOS）=20：80：10时的CS/PVA/CHOS纳米纤维膜相比于未搭载CHOS的CS/PVA纳米纤维膜，抑菌性提升了38.9%，溶解率提升了38.6%。     

溶剂对电纺聚酯纳米纤维可纺性的影响

利用静电纺丝法制备聚酯(PET)纳米纤维,选择苯酚和四氯乙烷,三氟乙酸,三氟乙酸和二氯甲烷3种溶剂分别溶解PET切片进行静电纺丝,通过扫描电子显微镜(SEM)对纤维表面形态进行观察,结果表明:三氟乙酸和二氯甲烷混合溶剂溶解PET制备的电纺纤维较好。使用视频光学接触角测定仪测试PET电纺纤维膜与其流延膜的接触角,通过分析两者表面结构,证明PET电纺纤维膜能产生较强的疏水功能。     

聚乳酸/肉桂醛复合纳米纤维膜的制备及表征

采用水溶液饱和法制备了肉桂醛/β环糊精包合物,将其添加到聚乳酸（PLA）溶液中,利用静电纺丝技术制备PLA/肉桂醛复合纳米纤维膜。利用扫描电子显微镜(SEM)探讨了静电纺丝条件对PLA纳米纤维膜纤维直径及表面形貌的影响,通过傅里叶变换红外光谱(FTIR)对PLA/肉桂醛复合纳米纤维膜做了特征官能团分析,并对其热力学性能、力学性能及抗菌性能进行了表征。结果表明,制备的PLA/肉桂醛复合纳米纤维膜纤维形态良好,平均直径为175 nm,FT IR研究显示肉桂醛与PLA之间属于物理混合。该复合纳米纤维膜热分解温度265.52 ℃,拉伸强度为2.45 MPa,对大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌都具有抑菌性,其中对金黄色葡萄球菌的抑菌性最强。     

熔体微分电纺PLA/ATBC纳米纤维膜吸油性能

静电纺丝制备的纳米纤维孔隙率高、吸附能力强,可用于高效地处理化工行业油污染问题。聚乳酸（PLA）作为生物可降解材料,来源广泛且不会造成二次污染,具有广阔的应用前景。本文利用自制的熔体微分电纺装置,制备了PLA/乙酰基柠檬酸三丁酯（ATBC）纤维膜,探究了物料性质和增塑剂ATBC含量对PLA纤维形貌及吸油性能的影响,并获得了最佳的纺丝温度和ATBC含量。研究表明,在纺丝温度为240℃、ATBC质量分数为10%时制备的纤维直径为320nm。该纤维膜水接触角为145°,表现出良好的疏水性能,吸油倍率为138.4g/g,是市售PP无纺布吸油性能的4～5倍,保油倍率为85.8g/g。重复吸/放油5次循环后,纤维膜仍具有良好的强度而未发生断裂且可继续进行吸油,重复使用性能较好,可被应用于化工行业油污染处理。     

CS/PEO纳米纤维膜的制备及其用于圣女果保鲜的研究

以壳聚糖(CS)和聚氧化乙烯(PEO)为原料,通过静电纺丝制得CS/PEO纳米纤维膜,利用正交实验优化静电纺CS/PEO纳米纤维膜的制备工艺条件;研究了CS/PEO纳米纤维膜的结构和性能及其应用于圣女果的包装保鲜,并与CS/PEO流延膜(简称流延膜)、浸渍CS/PEO溶液的普通保鲜膜(简称涂膜)、基于普通保鲜膜的CS/PEO纳米纤维复合膜(简称复合膜)、普通保鲜膜的应用效果进行比较。结果表明:正交实验得到静电纺CS/PEO纳米纤维膜的最佳条件为CS与PEO质量比8:2,电压16 kV,接收距离10 cm,在此条件下制得的CS/PEO纳米纤维膜的拉伸强度为14.2 MPa,断裂伸长率为43.6%;CS/PEO纳米纤维膜、流延膜各组分之间存在强的相互作用并具有很好的相容性;使用最佳条件下制得的CS/PEO纳米纤维膜包裹圣女果,相对于用流延膜、涂膜、复合膜、普通保鲜膜、其他条件下制得的CS/PEO纳米纤维膜包裹圣女果,其保鲜效果最好,用其包裹圣女果12d后,圣女果失重率最小为6.3%,维生素C含量最高为289.2μg/g。     

溶液性质对电纺聚乳酸/茶多酚复合纳米纤维膜形貌的影响

为了研究静电纺丝溶液性质对聚乳酸(PLA)/茶多酚(TP)复合纳米纤维膜的形貌与直径的影响,本文借助扫描电子显微镜(SEM)观察不同纺丝溶液条件下纳米纤维膜的外观形貌并计算纤维直径。结果表明:当PLA溶质质量分数为10%时,纤维成纤性最好。而纺丝溶剂采用二氯甲烷(DCM)和N,N-二甲基甲酰胺(DMF)的混合溶剂时,纤维形貌改善明显。同时不同PLA/TP质量混比条件下的纤维直径在380~854nm之间。     

工艺参数对PLA/CA复合纳米纤维形貌与直径的影响

为探究工艺参数对聚乳酸(PLA)/乙酸纤维素(CA)复合纳米纤维膜的影响,通过改变溶液质量分数、PLA与CA质量比、纺丝电压、供液速度、收集距离和辊筒转速等工艺参数,优化试验条件,确定最佳工艺参数。采用场发射扫描电镜观察复合纳米纤维膜的形貌,并使用Nano Measurer 1.2软件对纤维直径分布情况进行分析统计。结果表明,在PLA质量分数为12%、PLA与CA质量比为8∶2、纺丝电压为18 k V、注射泵供液速度为0.6 mL/h、收集距离为18 cm、辊筒转速为600 r/min的条件下,制备的PLA/CA纳米纤维形貌良好、分布均匀,平均直径为310.8 nm。     

Treatment of ramie fiber with different techniques: the influence of diammonium phosphate on interfacial adhesion properties of ramie fiber-reinforced polylactic acid composite

Ramie fiber-reinforced polylactic acid (PLA) composites were successfully prepared by hot compression molding. Different treatment techniques were used to modify the surface of ramie fiber. The influence of diammonium phosphate (DAP) on the interfacial adhesion between ramie fiber and PLA composites was investigated by the contact angle measurements, FTIR and SEM analyses. The contact angle measurement results showed that alkali treatment combined with DAP was very efficient in decreasing the hydrophilicity of fibers. After treatment, the hydrophilicity of untreated ramie fiber from 5.9 ± 1.3 decreased to 2.0 ± 0.8 mJ/m². The wettability of alkali/silane/DAP-treated ramie fiber/PLA composite was higher (95.4° ± 1.3°) than that of pure ramie fiber/PLA composite (87.3° ± 1.9°). The FTIR results were consistent with the wetting measurements as the increment of hydrophilicity. Thermal analysis indicated that DAP-modified ramie fiber/PLA composites exhibited a lower thermal decomposition temperature, unique decomposition behavior and more residual char formation at decomposition temperature. The tensile, flexural and impact properties of DAP-modified ramie fiber composites were comparable to those of untreated ramie fiber composite. Moreover, proper alignment and uniform distribution of ramie fibers within the PLA matrix were found to be excellent. The morphological structures observed by SEM showed that well-modified ramie fibers enhanced the failure of the PLA composites in tensile, flexural and impact tests.     

Controlled release of ketoprofen from electrospun porous polylactic acid (PLA) nanofibers

Electrospun fibers can be promising drug carriers for future biomedical applications. In this work, electrospun PLA fibers were developed as a new system for the delivery of ketoprofen which is a non-steroidal anti-inflammatory drug. For effective control of drug release, porous PLA fiber was prepared by phase separation during electrospinning. The release of various contents of ketoprofen from the electrospun PLA fiber was investigated at body temperature (37 °C) and at room temperature (20 °C). The release rates of the ketoprofen drug from the PLA/ketoprofen fibers showed a relatively higher release rate at 37 °C than at 20 °C. As the ketoprofen content increased, the release effect (cumulative drug released) increased. Thermal characteristic of PLA/ketoprofen fiber was also analyzed.     

Preparation and characterization of polyketone (PK) fibrous membrane via electrospinning

In this study, the aliphatic polyketone (PK) fibrous membrane was successfully prepared from the solution by electrospinning process at room temperature. As solvents for PK polymer, the mixed solvents of trifluoroacetic acid (TFA) and dichloromethane (MC) were used. Electrospun PK fibrous membrane was characterized by scanning electron microscope (SEM), wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), Fourier transform infrared spectrophotometer (FT-IR), and Raman spectroscopy, and compared to the corresponding cast PK film. The crystal structures of electrospun PK fiber and solvent cast PK film were characterized by WAXD. The result indicated that the crystal structure of cast PK film was assigned to α-form, while the crystal structure of PK fibrous membrane corresponded to β-form, which was attributed to fast crystallization during electrospinning process. Accordingly, the crystallinity of electrospun PK fibrous membrane was lower than that of solvent cast PK film. To confirm further these crystalline structures, FT-IR and Raman spectroscopy were employed.     

Electrospun polylactic acid non-woven mats incorporating silver nanoparticles

This research is focused on the influence of silver nanoparticles (AgNPs) on the spinnability, morphology and wetting properties of electrospun polylactic acid (PLA) non-woven mats. PLA was electrospun from a chloroform solution (4.7 % g/g) and a filament and beads morphology was obtained, the filaments having an average diameter of 1.25 μm. Interestingly, water contact angle measurements showed a contact angle of θ = 81°, an improvement relative to as-cast film which exhibited a contact angle of θ = 54°. When AgNP, of ca. 12 nm size, were incorporated at 1 % g/g relative to PLA weight, to the 4.7 % PLA-chloroform solution, and electrospun, the filaments diameter was greatly reduced to an average of 0.65 μm, and the density of polymer beads was also reduced. It is believed that the electric conductivity of silver enhanced the spinnability of the polymer solution. Strikingly, water contact angle measurements showed that the PLA/AgNP mats exhibited an angle as high θ = 134°. Increasing the solution concentration to 6.7 % g/g still produced a beads-and-filament morphology, but with larger filament diameters, probably due to an increase in solution viscosity. When AgNP were added (again at 1 % g/g relative to PLA weight), the occurrence of beads diminished and the average filament diameter decreased confirming the enhancement in spinnability by the AgNPs. Moreover, contact angles remained above 110° suggesting that the overall morphology is key to PLA’s mats hydrophobic behavior and not only filament diameter. Finally, the non-woven mats were rather amorphous, as revealed by differential scanning calorimetry and X-ray scattering, due presumably to the quenching process associated with the electrospinning process.     

Electrospinning superhydrophobic–superoleophilic PVDF-SiO2 nanofibers membrane for oil–water separation

Oil–water separation has attracted research interest due to the damages of oily wastewater caused to the environment and human beings. Electrospun fiber membrane has high oil–water separation performance. A nanofibers membrane with multi-stage roughness was prepared by electrospinning using poly(vinylidene fluoride)(PVDF)-silica blend solution as raw material. The result shows that the water contact angle (WCA) of the nanofibers membrane was promoted from 138.5 ± 1° to 150.0 ± 1.5° when the SiO₂ content was increased from 0 to 3 wt%. The nanofibers membranes exhibited excellent separation efficiency (99 ± 0.1%) under gravity drive, with high separation flux of 1857 ± 101 L·m⁻²·h⁻¹. More importantly, the obtained PVDF-SiO₂ nanofibers membranes showed excellent multi-cycle performance and stable chemical resistance, which would make them great advantages for the practical application of oil–water separation.     

Preparation of a superamphiphobic surface on a common cast iron substrate

A superamphiphobic (super-repellent) surface with both water and rapeseed oil contact angle higher than 150° was prepared on a common cast iron substrate. The water and rapeseed oil contact angles were 158 ± 1.9° and 151 ± 1.7°, respectively. The sliding angles of water and rapeseed oil on the superamphiphobic surface were 2° and 16°, respectively. Scanning electron microscope images showed that many interesting microflower-like microstructures comprised many nanorods with the average diameter of about 200 nm, which were distributed on the superamphiphobic cast iron substrate. Each nanorod was composed of many smaller nanostructures and nano particles, which created interesting micro–nano binary structures similar to the surface microstructures of lotus leaves. When kept in an ambient environment for 6 months, no rust was observed on the superamphiphobic cast iron substrate surface, which showed excellent corrosion resistance.     

静电纺PLA/丝素-明胶复合纤维膜的性能研究

通过静电纺丝先制备聚乳酸(PLA)纤维膜,在PLA纤维膜上分别喷射不同比例的丝素-明胶纺丝液制得PLA/丝素-明胶复合纤维膜,对复合纤维膜的溶解性能、尺寸稳定性、力学性能及生物性能进行表征。结果表明:与丝素-明胶纤维膜相比,PLA/丝素-明胶复合纤维膜的溶失率明显下降,尺寸稳定性及柔软性得到改善,且经甲醇处理后,复合纤维膜的力学性能提高。将制备的复合纤维膜进行小鼠胚胎细胞(3T3)培养实验,3T3在PLA/丝素-明胶复合纤维膜上能更好地粘附、伸展和繁殖。