Simulation of Jet Motion during Electrospinning Process through Coupled Multiphysics Method

Yuansheng Zheng,Yongchun Zeng,Xuan Dong 한국섬유공학회 2019 Fibers and polymers Vol.20 No.1

A multiphysics model, used for predicting jet velocity by solving incompressible Navier-Stokes equations coupled with electric volume force, has been developed to simulate the three-dimensional polymer jet produced during electrospinning process. By varying the parameter values in the model, the effects of parameters, including flow rate and viscosity of polymer solution, spinneret diameter, and applied voltage on jet velocity are discussed. This model is validated by comparing with experimental results.

Effect of Bacterial Wilt on Fungal Community Composition in Rhizosphere Soil of Tobaccos in Tropical Yunnan

Yuanxian Zheng,Jiming Wang,Wenlong Zhao,Xianjie Cai,Yinlian Xu,Xiaolong Chen,Min Yang,Feiyan Huang,Lei Yu,Yuansheng He 한국식물병리학회 2022 Plant Pathology Journal Vol.38 No.3

Bacterial wilt, which is a major soil-borne disease with widespread occurrence, poses a severe danger in the field of tobacco production. However, there is very limited knowledge on bacterial wilt-induced microecological changes in the tobacco root system and on the interaction between Ralstonia solanacearum and fungal communities in the rhizosphere soil. Thus, in this study, changes in fungal communities in the rhizosphere soil of tobaccos with bacterial wilt were studied by 18S rRNA gene sequencing. The community composition of fungi in bacterial wilt-infected soil and healthy soil in two tobacco areas (Gengma and Boshang, Lincang City, Yunnan Province, China) was studied through the paired comparison method in July 2019. The results showed that there were significant differences in fungal community composition between the rhizosphere soil of diseased plants and healthy plants. The changes in the composition and diversity of fungal communities in the rhizosphere soil of tobaccos are vital characteristics of tobaccos with bacterial wilt, and the imbalance in the rhizosphere microecosystem of tobacco plants may further aggravate the disease.

Effects of Temperature on Melt Electrospinning: Experiment and Simulation Study

Xiaoqi Mu,Yuansheng Zheng,Xueqin Li,Binjie Xin,Lantian Lin 한국섬유공학회 2021 Fibers and polymers Vol.22 No.4

In this study, the jet formation progress, jet motion, resultant fiber diameter, fiber mat morphology, inner structuresand mechanical properties of the fibers prepared at different heating temperatures via melt electrospinning system werestudied, in a comprehensive and systematic manner. The temperature distribution of the melt electrospinning configurationwas simulated, in order to provide a good deal of insight into the experimental results. High-speed photography was adoptedto capture the images of jet formation process and jet motion during melt electrospinning. The experimental results showedthat higher heating temperature at the spinneret results in shorter jet formation time, smaller fiber diameter, more disorderedfiber mat, lower degree of crystallinity and strength. The simulation works was carried out, aimed at facilitating to deeplyunderstand the experimental results.

Fabrication and Characterization of Graphene Enriched Polysulfon Amide Nanocomposites by Electrospinning System

Na Meng,Yuansheng Zheng,Binjie Xin 한국섬유공학회 2018 Fibers and polymers Vol.19 No.2

In this paper, we report on the fabrication and characterization of poly(sulfone amide)/graphene (PSA/G) nonwoven based nanocomposite mat assembled via electrospinning technique. Different types of nanocomposite mats were electrospun by varying the weight percentage of graphene in the polymer solution. The surface morphologies, chemical structural, thermal, and electrical properties of the nanocomposites were evaluated systematically. The morphology of the PSA/G nanocomposites exhibited that mesh-like ultrafine nanofibers were densely aligned. Thermal stability and electrical properties of the PSA/G composites could be improved obviously with the addition of graphene. And the thickness uniformity of the nanocomposite mat was improved by using an electrospinning system. Our experimental results suggested that the PSA/G nanocomposites have potential to serve in many different applications, especially in the area of electronic components.

The Effects of Electric Field on Jet Behavior and Fiber Properties in Melt Electrospinning

Xueqin Li,Yuansheng Zheng,Xiaoqi Mu,Binjie Xin,Lantian Lin 한국섬유공학회 2020 Fibers and polymers Vol.21 No.5

The electric field and temperature are the two important factors that influence the diameter and properties of fiberin the melt electrospinning process. It is commonly known that the polymer jet behavior is governed by the electric fieldwithin spinning area. In present work, a comprehensively-designed and properly-conducted analysis was carried out toinvestigate into the effects of electric field on the jet behaviors, diameters, crystalline structure and mechanical properties ofthe resultant fibers. An auxiliary electrode was invited to enhance the electric field strength. The high-speed photography wasadopted to capture the jet motion, and also, the numerical simulation was used to understand the electric field distribution. Bymaking use of the whipping amplitude and whipping frequency, the characteristics of jet behavior were described. It wasfound that by applying an auxiliary electrode, the average fiber diameter reduced from 61.01 μm to 9.06 μm, and thecrystallinity and strength of the fiber was improved with the help of the higher electric filed intensity. In addition, the moreuniform electric field would produce finer and more uniform fiber because of the more stable jet motion.

Effects of Electric Filed on Electrospray Process: Experimental and Simulation Study

Xuan Dong,Yuansheng Zheng,Binjie Xin,Huaiyuan Liu,Lantian Lin 한국섬유공학회 2020 Fibers and polymers Vol.21 No.11

At present, there exists a widely-held view that electric field plays an extremely important role in the electrosprayprocess. Aimed at investigating into the effects of electric field distribution and intensity on the electrospray process andresultant microsphere diameter, a variety of necessary and relevant tests were performed in this study by inviting an auxiliaryelectrode ring. The three-dimensional electric fields of the electrospray system were simulated, in addition, high-speedphotography was adopted to recognize the electrospray modes. The results of a series of electrospray experiments demonstratedthat not only electrospray mode but also resultant microsphere diameters are influenced, to a considerable degree, by the electricfield. Such simulation results were verified by above-mentioned experiments that from higher electric field intensity comessmaller microsphere diameter, due to the fission caused by the surface charge, and besides, more uniform electric fielddistribution produces more uniform microsphere diameter.

Effect of Electric Field Induced by Collector Shape on the Electrospun Jet Motion and Fiber Structure Evolution

Jiawen Shao,Yuansheng Zheng,Md All Amin Newton,Yong Li,Binjie Xin 한국섬유공학회 2023 Fibers and polymers Vol.24 No.10

The formation process of beaded structure electrospun fibers in three cases: spherical collector, bowl-shaped collector, and fold-shaped collector, and the influence of electric field on jet motion and the structural evolution of fiber morphology were investigated systematically in this work. In this study, the electric field simulation was performed with the simulation software; The high-speed camera recorded the jet motion, which was characterized using parameters such as the straight jet length, envelope angle,whipping amplitude, and jet velocity. The SEM technique was employed to measure the collected fiber felt. It is found that the different collector systems will have different electric field distributions in the jet area, thus affecting its jet motion and resultant fiber morphology. Observed results showed that the electrospinning system of the spherical collector produced a stronger electric field on the collector surface, which can fully stretch the fibers and beads, producing a smaller bead structure and fewer beads. When the fold-shaped collector was adopted, its surface electric field intensity decreased, resulting in a change in the jet whip, showing a larger envelope angle and whipping amplitude, and the jet velocity decreased slightly, generating a coarser beaded fiber. The surface electric field intensity decreased again when a bowl-shaped collector was employed, the whipping area of the jet was widened, and the speed of the jet decreased again, resulting in the fiber diameter and the bead diameter increasing. The results indicate that the jet motion can be controlled by changing the collector shape to control the electric field intensity distribution, and the desired fibers with different properties are obtained.ent properties are obtained.

Effect of Electric Field on the Directly Electrospun Nanofiber Yarns: Simulation and Experimental Study

Shixin Jin,Binjie Xin,Yuansheng Zheng,Shuhua Liu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.1

Electric field plays a key role in electrospinning process for nanofiber and nanofiber yarn producing. The electric field distribution of the yarn manufacturing system is simulated by using finite element method analysis. The effects of electric field distribution and intensity were studied to analyze the influence of the electric field on the electrospun nanofiber yarn surface morphology, mechanical, thermal and water absorption properties. The results show that the morphology anddiameters of nanofiber and yarn were obviously affected by the electric field with changing the needle distance and applied voltage, which further influence the mechanical performance of the yarn. The needle distance does not much affect the thermal property of the PSA electrospun yarn, whereas the yarn obtains better thermal resistance properties at voltage of 25 kV. The nanoyarn electrospun and assembled under higher applied voltage is proved to have a better wicking property in our research.

Melt-Electrospun Polyvinylbutyral Bonded Polypropylene Composite Fibrous Mat: Spinning Process, Structure and Mechanical Property Study

Jinhao Xu,Fuli Zhang,Binjie Xin,Yuansheng Zheng,Chun Wang,Shixin Jin 한국섬유공학회 2020 Fibers and polymers Vol.21 No.7

In this study, a novel polyvinylbutyral (PVB) bonded polypropylene (PP) composite fibrous mat was fabricated viamelt-electrospinning. In order to enhance the structure stability and mechanical properties of pristine PP fibrous mat system,preparation and characterization of the composite fibrous material by mixing different percentages of PVB and PP wasdesigned. The PVB can form bonding point between the PP fibers, which can ease the slip phenomenon between strainedfibers. The structure, morphology, tensile and tearing stress were measured systematically. The resultants exhibited that thetensile stress and tearing strength of composite fibrous mats were increased from 30.13 to 43.73 kPa and from 0.07 to 0.5 N,respectively. Meanwhile, the straight jet length and whipping range of each electrospun jets were analyzed via the imagescaptured by a high-speed photography system during the spinning process. The experimental resultants depicted thatcomposite system can lead to longer straight jet length and smaller whipping range.

Preparation of Waterproof and Breathable Polyurethane Fiber Membrane Modified by Fluorosilane-modified Silica

Yunge Yu,Yan Liu,Fuli Zhang,Shixin Jin,Yaqian Xiao,Binjie Xin,Yuansheng Zheng 한국섬유공학회 2020 Fibers and polymers Vol.21 No.5

Polyurethane is a thermoplastic elastomer with excellent physical and chemical properties, the hydrophilicity ofPU limits the wide application in the waterproof and breathable materials market. In this study, SiO2 nanoparticles werehydrophobically modified by fluorosilane to prepare the fluorosilane-modified silica (F-SiO2), then it was added into thesynthesized polyurethane to prepare waterproof and breathable film (F-SiO2/PU) by electrospinning. Compared withpolyurethane membranes, F-SiO2/PU composite membranes could form rough morphological surface through the blendingof F-SiO2. The experimental results showed that the water contact angle of the composite nanofiber membranes increase withthe addition of the amount of modified silica, and the water contact angle reached 135 o when the dosage of F-SiO2 was5 wt%. The composite nanofiber membranes could be endowed with excellent waterproof performance, hydrophobicity(50 kPa) and moisture permeability (10.4 kg/m2·h). Besides, the prepared membrane can remain the hydrophobic propertystability under the dynamic tensile of large-scale deformation.