Fabrication and characterization of electrospun Plantago major seed mucilage/PVA nanofibers

Electrospinning is a well-known technique for producing nanofibers using synthetic and natural polymers like mucilage. In this study, Plantago major Mucilage (PMM) was blended with polyvinyl alcohol (PVA) as a nontoxic adding agent, in order to produce electrospun nanofiber. Electrospinning parameters (voltage, tip-to-collector distance, feed rate, and PMM/PVA ratio) were optimized and solution properties were analyzed. The morphology of nanofibers was investigated using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray diffraction (XRD), and Brunauer–Emmett–Teller (BET). Mechanical strength of nanofibers was determined, and cell viability on nanofibers was discussed by MTT assay. The results of SEM indicated that the PMM/PVA (50/50) nanofibers obtained with average diameter of 250 nm. Viscosity, electrical conductivity, and surface tension of PMM/PVA solution were 550 Cp, 575 μS/cm, and 47.044 mN/m, respectively. FTIR and XRD results verified the exiting PMM in produced nanofibers and no chemical reaction between PMM and PVA. Improvement in mechanical strength and cell viability of nanofibers by adding PMM to PVA nanofibers indicated the potential application of PMM-based nanofibers for medical and food industries. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47852.     

聚乙烯醇纳米纤维膜的制备

采用静电纺丝方法制备了聚乙烯醇(PVA)纳米纤维,探讨了工艺参数对纳米纤维形貌的影响,并对PVA纳米纤维膜进行热处理,研究了热处理时间与温度对纳米纤维膜力学性能的影响。研究表明:PVA质量分数在6%~10%区间内变化时,可得到直径分布较为均匀的纳米纤维;在其它条件相同时,随纺丝电压的升高,PVA纳米纤维的不匀增大;接收距离的改变对PVA纳米纤维的直径变化影响不大;随PVA质量分数的增加,纳米纤维膜的断裂强度和断裂伸长率逐渐增大;在热处理时间相同时,PVA纳米纤维膜的断裂强度随温度的升高而增大;处理温度相同时,随处理时间的延长,PVA纳米纤维膜的断裂强度变化不大。     

PVA／MC纳米纤维膜的制备与吸水性、保水性研究

采用水热工艺和电纺方法制备了PVA／MC纳米纤维膜;对PVA／MC混和溶液的粘度、PVA／MC纳米纤维膜的结构、吸水性能和保水性能进行了研究。结果表明,随着MC含量的增加,PVA／MC混和溶液的粘度逐渐增大;FESEM表明,本身不能电纺的MC在与PVA混和则可以电纺制得PVA／MC纳米纤维膜,但随着MC含量的增加,混和溶液的粘度会逐渐增大而无法电纺;在不改变电压的情况下增大电纺的接受距离,所得PVA／MC纤维膜连续、直径均匀、表面光滑平整;吸水性能和保水性能研究表明,随着MC含量的增加,PVA／MC纳米纤维膜的吸水速率和保水性能逐渐提高。     

5-Fluorouracil-loaded poly(vinyl alcohol)/chitosan blend nanofibers: morphology,drug release and cell culture studies

Electrospun polymeric nanofibers as carriers for anticancer drugs have received a great deal of attention to treat tumor cells. This work was aimed to prepare an optimized nanofibrous sample based on poly(vinyl alcohol) (PVA)/chitosan (CS) blend, and then evaluate it containing 5-fluorouracil (5-FU) in terms of morphology, drug release, and cell culture. The electrospinning conditions to produce PVA/CS (50/50) blend nanofibers with an average diameter of approximately 150.8 nm were adjusted as follows: applied voltage 17 kV, needle tip to collector distance 60 cm, and flow rate 0.1 mL/h. The obtained results from Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) showed that there were no chemical interactions between the polymers and drug during the electrospinning process and the uniform morphology without beads. Moreover, to prolong 5-FU release from the blend nanofibers, three layered samples consisting of PVA/CS blend and poly (ε-caprolactone) (PCL) [PVA/CS-PCL 3-layers] were electrospun. On the other hand, by adding PCL in the PVA/CS blend nanofibers, the samples showed more hydrophobic property. Eventually, thiazolyl blue (MTT) assay along with NIH 3T3 cells culture proved that the sample could kill more than 80% of the cells. This formulation could be a promising candidate for cancer therapy potentially.

     

再生丝素蛋白/聚乙烯醇共混纳米纤维的静电纺丝研究

以静电纺丝方法制备再生丝素蛋白/聚乙烯醇共混纳米纤维。研究了共混配比、溶液浓度、添加剂含量及电纺电压、喷丝距离等因素对纤维成形及纤维有关性能的影响。研究表明:与聚乙烯醇共混后再生丝素纤维的柔韧性有一定改善,适当增加PVA在共混物中的含量、提高纺丝液浓度以及纺丝电压有利于改善共混溶液的可纺性。另外,加入丙三醇虽可使纤维直径的均匀性有所提高,但却不利于纤维成形。     

Influence of the processing parameters on needleless electrospinning from double ring slits spinneret using response surface methodology

Needleless electrospinning technology was an effective processing method which can fabricate large scale nanofibers. We first developed a novel double rings slit spinneret to overcome the shortcomings of current needleless electrospinning spinnerets. The solution of the flow rate was controlled accurately by peristaltic control pump. Response surface methodology was adopted to investigate the influence of the processing parameters on the morphology and diameter of nanofibers. The main spinning processing parameters comprised solution concentration, applied voltage, collection distance and solution flow rate. The analysis of variance was used to evaluate response surface reduced quadratic model for nanofiber diameter. The linear and quadratic coefficients were obtained. The morphology of nanofibers was observed by scanning electron microscopy. Effects of different processing parameters on the nanofiber mean diameter have been discussed. Predicated values have a good agreement with actual values for nanofiber diameter. Actual nanofiber diameter ranges from129.15 to 404.70 nm with different process parameters. Mechanical properties of nanofiber membrane have been investigated. High quality and high throughout nanofiber could be continuously produced. This novel needleless electrospinning spinneret has a great potential for large scale nanofibers production to promote electrospinning technology development. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46407.     

小麦蛋白/聚乙烯醇复合纳米纤维的制备及其表征

以小麦蛋白、聚乙烯醇(PVA)为原料,采用静电纺丝法制备小麦蛋白/PVA共混复合纳米纤维,重点研究纺丝液质量分数、电压、接收距离对纤维形态的影响,利用扫描电镜、傅里叶变换红外光谱、X-射线衍射光谱对纤维的形态与结构进行表征。结果表明:在纺丝液质量分数10%、小麦蛋白与PVA质量比8∶2、电压12 kV、接收距离10 cm的条件下,可以制备平均直径为280 nm左右的均一、表面光滑的纳米纤维。小麦蛋白与PVA复合后,分子间以氢键结合。     

Preparation of atactic poly(vinyl alcohol)/silver composite nanofibers by electrospinning and their characterization

Poly(vinyl alcohol) (PVA)/silver composite nanofibers were successfully prepared by the electrospinning method. Water‐based colloidal silver in a PVA solution was directly mixed without any chemical or structural modifications into PVA polymer fibers to form organic–inorganic composite nanofibers. The ratio of silver colloidal solution to PVA played an important role in the formation of the PVA/silver composite nanofibers. We prepared two different atactic PVA/silver nanocomposites with number‐average degrees of polymerization of 1700 and 4000 through electrospinning with various processing parameters, such as initial polymer concentration, amount of silver colloidal solution, applied voltage, and tip‐to‐collector distance. The PVA/silver composite nanofibers were characterized by field emission scanning electron microscopy and transmission electron microscopy (TEM). TEM images showed that silver nanoparticles with an average diameter of 30–50 nm were obtained and were well distributed in the PVA nanofibers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Facile preparation and characterization of poly(vinyl alcohol)/chitosan/graphene oxide biocomposite nanofibers

Poly(vinyl alcohol) (PVA)/chitosan (CS)/graphene oxide (GO) biocomposite nanofibers have been successfully prepared using aqueous solution by electrospinning. CS colloidal gel in 1% acetic acid can be changed to homogeneous solution by using electron beam irradiation (EBI). The uniform distributions of GO sheets in the nanofibers were investigated by field emission scanning electron microscopy (FESEM) and Raman spectroscopy. FESEM images illustrated that the spread single GO sheet embedding into nanofibers was formed via self-assembly of GO sheet and PVA/CS chains. And the average diameters of the biocomposite nanofibers decreased (200, 173, 160 and 123 nm) with increasing the contents of GO (0.05, 0.2, 0.4 and 0.6 wt%). Raman spectra verified the presence of GO in the biocomposite nanofibrous mats. The mechanical properties of as-prepared materials related with GO contents. It revealed that the highest tensile strength was 2.78 MPa, which was 25% higher than that of neat PVA/CS nanofibers. Antibacterial test demonstrated that the addition of GO to PVA/CS nanofiber had great ability to increase inhibition zone till 8.6 mm. Overall, these features of PVA/CS/GO nanofibers which were prepared by eco-friendly solvent can be a promising candidate material in tissue engineering, wound healing and drug delivery system.     

丝素蛋白-聚乙烯醇共混改性电纺膜的制备

采用静电纺丝技术,以特殊设计的金属丝螺旋盘绕滚筒作为接收装置,制备了具有一定取向的丝素蛋白(SF)-聚乙烯醇(PVA)共混纳米纤维材料。利用扫描电子显微镜(SEM)对纤维形貌进行观察,并通过Image-Pro Plus软件对纤维细度进行测试,探讨了SF与PVA的配比以及纺丝电压、接收距离等静电纺丝参数对所得纳米纤维形貌、细度及其分布的影响。结果表明:将质量浓度为25 kg/L的SF与质量分数为8%的PVA以质量比15∶3.2共混,并采用20 kV的纺丝电压和13 cm的接收距离静电纺时,所得纳米纤维的平均直径约为238 nm,且直径分布较为均匀。采用该法制得的纳米纤维材料具有一定的纤维取向,有利于细胞生长,可应用于生物医药领域。     

Determination of optimal production parameters for polyacrylonitrile nanofibers

The object of this work is to determine the most suitable values of process and solution parameters for electrospinning of polyacrylonitrile (PAN) nanofibers including solution concentration, applied voltage, and working distance between the needle tip and the collector plate. To investigate the effects of those parameters on the fiber morphology, nanofiber mat samples were produced by changing the value of parameters systematically. The scanning electron microscope images of these samples were analyzed to realize the effects of these parameters on the nanofiber morphology. Our results demonstrate that the diameter of the fibers increases with increasing concentration. However, the diameter reduces as the applied voltage and working distance between needle tip and the collector increase up to a certain value. In addition to this, viscosity and applied voltage have a strong effect on the uniformity and morphology of the nanofibers. Moreover, a relationship between spinning distance, voltage supplied, solution concentration, charge density, bead formation, and the diameter of the electrospun PAN nanofiber were established in the study. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Cross-linked electrospun polyvinyl alcohol/sodium caseinate nanofibers for antibacterial applications

In this study, the polyvinyl alcohol (PVA) and sodium caseinate (SC) nanofibers were produced by a single-fluid electrospinning method from their blends. Afterward, the cross-linking process with two different methods was applied to the PVA/SC (70/30, v/v) ratio, which was selected according to the surface and mechanical properties of the electrospun mat. In the first method, different ratios (15%, 20%, 25%, and 30%) of glutaraldehyde (GLA) cross-linking agents were added to the PVA/SC solution and then, PVA/SC/GLA nanofibers were obtained. In the second method (in-situ method), the nanofibers obtained from the PVA/SC solution were cross-linked by dipping into the cross-linking solution. After, PVA/SC/GLA/Zinc oxide nanoparticles (ZnO NP) mats were obtained by adding ZnO NP at different rates to the PVA/SC/GLA (7030-25GLA) solution, which was chosen according to the results of thermal, mechanical, and moisture test. In addition, performing tests, a cytotoxicity test for fibroblast cell line (L929), and in vitro antibacterial test for Escherichia coli and Staphylococcus aureus were also applied to them. Therefore, the usability of PVA/SC/GLA/ZnO NP nanofibers as an antibacterial effective wound dressing was investigated. Due to the high toxic effect of GLA, it was found that PVA/SC/ZnO cross-linked nanofibers are not suitable for wound dressing use. However, it was determined that the PVA/SC nanofiber cross-linked by the in-situ method had high cell viability according to the cytotoxicity test result and thus could be used as a fibroblast tissue scaffold.     

Effect of air blowing on the morphology and nanofiber properties of blowing‐assisted electrospun polycarbonates

Polycarbonate (PC) nanofibers are prepared using the air blowing‐assisted electrospinning process. The effects of air blowing pressure and PC solution concentration on the physical properties of fibers and the filtration performance of the nanofiber web are investigated. The air blowing‐assisted electrospinning process produces fewer beads and smaller nanofiber diameters compared with those obtained without air blowing. Uniform PC nanofibers with an average fiber diameter of about 0.170 μm are obtained using an applied voltage of 40 kV, an air blowing pressure of 0.3 MPa, a PC solution concentration of 16%, and a tip‐to‐collection‐screen distance (TCD) of 25 cm. The filtration efficiency improvement of the air blowing‐assisted electrospun web can be attributed to the narrow distribution of fiber diameter and small mean flow pore size of the electrospun web. Performance results show that the air blowing‐assisted electrospinning process can be applied to produce PC nanofiber mats with high‐quality filtration. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

静电纺间位芳纶纳米纤维的制备工艺参数

通过静电纺丝方法,将氯化锂/N,N–二甲基乙酰胺(Li Cl/DMAc)溶解间位芳纶(PMIA)制备了PMIA纳米纤维,探索了溶液浓度、接收距离、纺丝电压及接收速度等工艺参数对纤维形貌及其直径分布的影响。通过扫描电子显微镜观察了PMIA纳米纤维形貌及应用Image-J软件测量统计了PMIA纤维直径。结果表明,溶液浓度为8%~10%、纺丝电压为16~18 k V、接收距离为15~20 cm,接收速度60~80 r/min的范围内,间位芳纶纳米纤维成型良好,直径分布范围为100~120 nm;PMIA纳米纤维直径随着溶液浓度的减小、静电电压的增加而减小,随着接收速度的增加纤维取向增加。     

聚乙烯醇静电纺丝纳米纤维的制备及形貌研究

利用静电纺丝技术制备聚乙烯醇（PVA）纳米纤维材料,通过正交试验调节制备过程中纺丝电压、纺丝距离和纺丝溶液浓度等工艺参数,探究其对PVA纳米纤维直径大小、直径分布以及纤维形貌的影响。结果表明,影响纳米纤维形貌的主要因素排序是纺丝溶液浓度＞纺丝距离＞纺丝电压,并确定最优水平组合为纺丝电压为20 kV,PVA纺丝溶液浓度为6 %(质量分数,下同),纺丝距离为12 cm。     

Needleless electrospinning of nanofibers with a conical wire coil

In this article, we have demonstrated a novel needleless electrospinning of PVA nanofibers by using a conical metal wire‐coil as spinneret. Multiple polymer jets were observed to generate on the coil surface. Up to 70 kV electric voltage can be applied to this needleless electrospinning nozzle without causing “corona discharge.” Compared with conventional needle electrospinning, this needleless electrospinning system produced finer nanofibers on a much larger scale, and the fiber processing ability showed a much greater dependence on the applied voltage. Finite element calculation indicates that the electric field intensity profiles for the two systems are also quite different. This novel concept of using wire coil as the electrospinning nozzle will contribute to the further development of new large‐scale needleless electrospinning system for nanofiber production. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

聚乙烯醇及其共混液的电纺性研究

研究了聚乙烯醇(PVA)的浓度、纺丝电压和固化距离对PVA静电纺丝的影响。扫描电镜等结果显示:PVA的浓度(质量体积百分数)为5%￣8%、纺丝电压为6.6￣15kV和固化距离为5￣25cm时适合静电纺丝。PVA分别与海藻酸钠、可溶性淀粉和壳聚糖的混合溶液在一定浓度范围内可纺性好,可得到具有较好纤维形态的纤维。     

Photoluminescent electrospun polymeric nanofibers incorporating germanium nanocrystals

The photoluminescent germanium nanocrystals (Ge-NCs) were successfully incorporated into electrospun polymeric nanofiber matrix in order to develop photoluminescent nanofibrous composite web. In the first step, the synthesis of Ge-NCs was achieved by nanosecond pulsed laser ablation of bulk germanium wafer immersed in organic liquid. The size, the structural and the chemical characteristics of Ge-NCs investigated by TEM, XPS, XRD and Raman spectroscopy revealed that the Ge-NCs were highly pure and highly crystalline having spherical shape within 3–20 nm particle size distribution. In the second step, Ge-NCs were mixed with polyvinyl alcohol (PVA) polymer solution, and then, Ge-NC/PVA nanofibers were obtained via electrospinning technique. The electrospinning of Ge-NCs/PVA nanoweb composite structure was successful and bead-free Ge-NCs/PVA nanofibers having average fiber diameter of 185 ± 40 nm were obtained. The STEM analysis of the electrospun Ge-NCs/PVA nanofibers elucidated that the Ge-NCs were distributed homogeneously in the polymeric nanofiber matrix. The UV–Vis absorption and photoluminescence spectroscopy studies indicated the quantum confinement effect of Ge-NCs on the optical properties of the electrospun Ge-NCs/PVA nanoweb.     

Thermal and morphological properties of PVA/4‐vinylbenzene boronic acid hybrid nanofibrous

The aim of this study was to investigate the preparation and characterization of PVA and PVA/4‐VBBA (4‐Vinylbenzene boronic acid) hybrid electrospun nanofiber mat. PVA was mixed with cross‐linkable 4‐Vinylbenzene boronic acid (4‐VBBA), enabling the polymer to cross‐link upon UV irradiation. The photo‐cross‐linking reaction was characterized by a Fourier transform infrared spectroscopy. The structure and morphology of electrospun membranes were investigated by scanning electron microscopy (SEM). SEM images showed that the nanofiber diameter and the nanostructured morphology depended on solution viscosity, applied electric voltage(AV), tip to collector distance (TCD), and the amount of the 4‐VBBA. The thermal properties of PVA and PVA/4‐VBBA hybrid nanofibers were investigated by thermo gravimetric analysis. The photo‐crosslinked nanofibers were insoluble in water. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

The influence of solvent type and polymer concentration on the physical properties of solid state polymerized PA66 nanofiber yarn

We investigated the effects of two different solvent types and three solution concentrations on the electrospinning of solid state polymerized polyamide 66 (SSP PA66) nanofiber yarns. Nanofiber yarns were electrospun from SSP PA66 solutions in formic acid and formic acid/chloroform (3/1), using two oppositely metallic spinnerets system. Scanning electron microscopy (SEM) and X‐ray diffraction (XRD) were employed to characterize the morphology and properties of the nanofibrous yarns. Experimental results show that adding chloroform to formic acid as a binary solvent increases viscosity of polymer solution and the nanofibers diameter significantly. XRD patterns reveal that the presence of chloroform affects the crystallinity and the mechanical properties of the produced nanofibrous yarns. PA66 nanofiber yarn from 10 wt % formic acid/chloroform (3/1) solution was successfully electrospun with strength and modulus of 120.16 MPa and 1216.27 MPa respectively. It is also shown that the solution concentration has a significant effect on the modulus of the nanofibers yarns. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012