Nanoscience and Nanotechnology Commons^™

Enhanced Triboelectric Effect Using Functionalized Multiwalled Carbon Nanotube-Coated Fiber Mats For Biomechanical Energy Harvesting, Fernando Viesca, Diego De Leon, Kevin Alejandro, Rigobert Ybarra Jr., Md. Wasikur Rahman, Victoria Padilla, Horacio Vasquez, Karen Lozano, M. Jasim Uddin

Mechanical Engineering Faculty Publications

Triboelectric nanogenerators (TENGs) have emerged as a cutting-edge technology for developing self-powered wearable electronic devices. In this study, TENGs were fabricated using two fiber mats: forcespun polytetrafluoroethylene (FS-PTFE) microfibers and electrospun polyvinyl alcohol (ES-PVA) nanofiber (NF) mats. The FS-PTFE mats were coated with functionalized multiwalled carbon nanotubes (MWCNTs). Functionalized MWCNTs were dispersed in water-based solutions containing three different surfactants—sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and Triton X-100 to enhance fiber interaction. The NF mats were subsequently immersed in aqueous systems. The surfactant facilitated the uniform deposition of COOH-MWCNTs onto the FS-PTFE fibers, serving as a negative layer, while ES-PVA mat …

Synthesis Of Activated Carbon From Coconut Shell And Recycled Styrofoam Nanofiber For Water Filtration, Rahma Dani, Ismet Ismet, Leni Marlina, Rona Alisya, Muhamad Abel Kirana Aldi, Anggi Ludiansyah, Lintang Auliya Kurdiati, Meutia Kamilatun Nuha Ap Idjan, Agung Mataram, Muhammad Rama Almafie, Ida Sriyanti

Makara Journal of Science

Water pollution affects life sustainability; hence, several efforts have been exerted to overcome this problem. For ex-ample, nanofiber membrane technology is introduced to retain solutes while allowing only water molecules to pass through the system. Therefore, this study aimed to maximize the technology for water filtration using the electrospin-ning method by combining Styrofoam waste-based polymer with activated carbon from coconut shell waste (ACCS). The nanofiber diameter produced ranged from 590 nm to 610 nm with porous characteristics and without beads. The carbon content varied from 68.04% to 69.84%, according to the energy dispersive X-ray measurement, demonstrating the composite’s effectiveness. The …

Validation, Optimization, And Experimentation Of Electro-Centrifugal Spinning, Carlos Alberto Delgado

Theses and Dissertations

The aim of this study is to understand the behavior of polymeric solutions, when exposed to both electric fields and centrifugal forces through the electro-centrifugal fiber creation method, observing both effects of various parameter variations on the resulting nanofibers. The elemental deposition on electrospun fibers through in-situ processes is studied and optimized. The morphology, crystallinity, thermal properties, and elemental composition of the nanofibers were characterized. The purpose of these nanofibers is for future applications such as energy harvesting, filtration, and biomedical applications.

Mesoporous Particle Embedded Nanofibrous Scaffolds Sustain Biological Factors For Tendon Tissue Engineering, Chiara Rinoldi, Ewa KijeńSka-GawrońSka, Marcin Heljak, Jakub Jaroszewicz, Artur KamińSki, Ali Khademhosseini, Ali Tamayol, Wojciech Swieszkowski

Department of Mechanical and Materials Engineering: Faculty Publications

In recent years, fiber-based systems have been explored in the frame of tissue engineering due to their robustness in recapitulating the architecture and mechanical properties of native tissues. Such scaffolds offer anisotropic architecture capable of reproducing the native collagen fibers’ orientation and distribution. Moreover, fibrous constructs might provide a biomimetic environment for cell encapsulation and proliferation as well as influence their orientation and distribution. In this work, we combine two fiber fabrication techniques, such as electrospinning and wet-spinning, in order to obtain novel cell-laden 3D fibrous layered scaffolds which can simultaneously provide: (i) mechanical support; (ii) suitable microenvironment for 3D …

Investigation Of Coo Ato For Solar Cells And Infrared Sheaths, Manopriya Devisetty Subramanyam

USF Tampa Graduate Theses and Dissertations

Solar as an energy source is expected to grow fastest from now to 2050. Increasing the efficiency is usually achieved by increasing the short circuit current density (JSC) and/or the fill factor. Improving the efficiency of solar cells will be an ongoing effort.Structurally solar technologies can be classified into two types, wafer-based and thin-film-based. Wafer solar cells have been used in this study. The anti-reflective layer on top of solar cells has been fabricated by a process called electrospinning to tune the solar cells' top surface with the desired thickness and dimensions of the nanofibers. The nanofibers' dimensions, shape, and …

Large-Scale Synthesis Of Compressible And Re-Expandable Three-Dimensional Nanofiber Matrices, Alec Mccarthy, Lorenzo Saldana, Daniel Mcgoldrick, Johnson V. John, Mitchell Kuss, Shixuan Chen, Bin Duan, Mark A. Carlson, Jingwei Xie

Department of Mechanical and Materials Engineering: Faculty Publications

Due to their biomimetic properties, electrospun nanofibers have shown great potential in many biomedical fields. However, traditionally-produced nanofibers are typically two-dimensional (2D) membranes limiting their applications. Herein, we report a large-scale synthesis of compressible and reexpandable three-dimensional (3D) nanofiber matrices for potential biomedical applications. The reproducible mass production of such matrices is achieved using a multiple-emitter electrospinning machine with a controlled environment (e.g., temperature, humidity, and air flow rate) followed by an innovative gas-foaming expansion. The modified 20-emitter circular array with 3D-printed needle caps is capable of maintaining stable Taylor cones under extremely high flow rates. The introduction of such …

Artificial Synthetic Scaffolds For Tissue Engineering Application Emphasizing The Role Of Biophysical Cues, Samerender Nagam Hanumantharao

Dissertations, Master's Theses and Master's Reports

The mechanotransduction of cells is the intrinsic ability of cells to convert the mechanical signals provided by the surrounding matrix and other cells into biochemical signals that affect several distinct processes such as tumorigenesis, wound healing, and organ formation. The use of biomaterials as an artificial scaffold for cell attachment, differentiation and proliferation provides a tool to modulate and understand the mechanotransduction pathways, develop better in vitro models and clinical remedies. The effect of topographical cues and stiffness was investigated in fibroblasts using polycaprolactone (PCL)- Polyaniline (PANI) based scaffolds that were fabricated using a self-assembly method and electrospinning. Through this …

Nano Fab Lab 63, Brian K. Deemer, Josh Clemons, Nick Brodine, Delaney Fitzsimmons

Mechanical Engineering

Lawrence Livermore National Laboratories (LLNL) has several steps in the production process for ceramic nanofiber tubes that they would like to improve - electrospinning, cutting, rolling, sealing and heat treating. We undertook the challenge to deliver LLNL with a semi-automated process that efficiently integrates the steps of cutting, rolling, and sealing to save time and improve control over end dimensions. In this document, we discuss the technical background of the manufacturing steps currently followed to create nanofiber tubes, identify which steps are incorporated in our prototype and explain how they will interface with one another, define the design requirements, present …

Optimizing Electrospun Ceramic Nanofiber Strength Through Two-Step Sintering, Michael Ross

Materials Engineering

Two-step sintering (TSS) consists of a high-temperature step and immediate cooling to a sintering temperature for an extended sintering time, where grain growth is suppressed by severe densification during the high-temperature step. TSS is adopted to enhance mechanical properties of electrospun ceramic nanofibers (CNFs), a class of porous ceramics used for environmental remediation, optoelectronics, and filtration. PVP and Ga(NO₃)₃ nanofiber mesh, provided by Lawrence Livermore National Laboratory, was shaped, oxidized, and two-step sintered to form a nanocrystalline β-Ga₂O₃ CNF tube using a high-temperature step of 1,000^oC. Sintering temperatures and times varied from …

Electrospinning Novel Aligned Polymer Fiber Structures For Use In Neural Tissue Engineering, Rachel Martin

Dissertations, Master's Theses and Master's Reports

A suitable tissue scaffold to support and assist in the repair of damaged tissues or cells is important for success in clinical trials and for injury recovery. Electrospinning can create a variety of polymer nanofibers and microfibers, and is being widely used to produce experimental tissue scaffolds for neural applications. This dissertation examines various approaches by which electrospinning is being used for neural tissue engineering applications for the repair of injuries to the central nervous system (CNS) and the peripheral nervous system (PNS). Due to the poor regeneration of neural tissues in the event of injury, tissue scaffolds are being …

Molecular Combing Of Dna Nanofibers And Comparison To Electrospinning, Tanner L. Buresh

UCARE: Research Products

The goal of these experiments was to create DNA nanofibers through the method of molecular combing (MC) and then compare the MC fibers to fibers created with electrospinning (ES). The experiment was designed and initial samples were created. After confirming that the method would succeed in creating DNA fibers, several parametric studies were performed in order to optimize the experiment and create the most uniform fibers possible. The parametric studies were done on the following variables: substrate material, pH level of DNA solution, and DNA solution concentration. After completion of all experiments, it was determined that although fibers could be …

A Comparative Study Of Polyurethane Nanofibers With Different Patterns And Its Analogous Nanofibers Containing Mwcnts, Javier Macossay-Torres, Faheem A. Sheikh, Hassan Ahmad, Hern Kim, Gary L. Bowlin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Tissue engineering is a multidisciplinary field that has evolved in various dimensions in recent years. One of the main aspects in this field is the proper adjustment and final compatibility of implants at the target site of surgery. For this purpose, it is desired to have the materials fabricated at the nanometer scale, since these dimensions will ultimately accelerate the fixation of implants at the cellular level. In this study, electrospun polyurethane nanofibers and their analogous nanofibers containing MWCNTs are introduced for tissue engineering applications. Since MWCNTs agglomerate to form bundles, a high intensity sonication procedure was used to disperse …

Electrospinning Of Polycaprolactone Core-Shell Nanofibers With Anti-Cancer Drug, Sakib Iqbal, Mujibur Khan, Saheem Absar, Andrew Diamanduros, Samuel Chambers

GS4 Student Scholars Symposium

Encapsulation of a model anti-cancer drug, 5-Fluorouracul (5-FU) into biocompatible core-shell nanofibers of polycaprolactone (PCL) nanofibers was fabricated using a coaxial electrospinning process. Our work aims to solve these issues using a novel method of fabrication of fibers featuring confinement of drugs within a biodegradable core-shell structure, thereby permitting sustained release of drugs to specific sites of treatment, such as tissues affected with tumor cells. The coaxial electrospinning was performed using a sheath polymer solution consisting of a 14 wt% PCL solution and a 5 wt% solution of 5-FU as the core solution. Dimethylformamide (DMF) was used as the solvent …

Imaging, Spectroscopy, Mechanical, Alignment And Biocompatibility Studies Of Electrospun Medical Grade Polyurethane (Carbothane™ 3575a) Nanofibers And Composite Nanofibers Containing Multiwalled Carbon Nanotubes, Faheem A. Sheikh, Javier Macossay-Torres, Travis Cantu, Xujun Zhang, M. Shamshi Hassan, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, Hern Kim, Gary L. Bowlin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

In the present study, we discuss the electrospinning of medical grade polyurethane (Carbothane™ 3575A) nanofibers containing multi-walled-carbon-nanotubes (MWCNTs). A simple method that does not depend on additional foreign chemicals has been employed to disperse MWCNTs through high intensity sonication. Typically, a polymer solution consisting of polymer/MWCNTs has been electrospun to form nanofibers. Physiochemical aspects of prepared nanofibers were evaluated by SEM, TEM, FT-IR and Raman spectroscopy, confirming nanofibers containing MWCNTs. The biocompatibility and cell attachment of the produced nanofiber mats were investigated while culturing them in the presence of NIH 3T3 fibroblasts. The results from these tests indicated non-toxic behavior …

Imaging, Spectroscopic, Mechanical And Biocompatibility Studies Of Electrospun Tecoflex® Eg 80a Nanofibers And Composites Thereof Containing Multiwalled Carbon Nanotubes, Javier Macossay-Torres, Faheem A. Sheikh, Travis Cantu, Thomas Eubanks, M. Esther Salinas, Chakavak S. Farhangi, Hassan Ahmad, M. Shamshi Hassan, Myung-Seob Khil, Shivani K. Maffi, Hern Kim, Gary L. Bowlin

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The present study discusses the design, development and characterization of electrospun Tecoflex® EG 80A class of polyurethane nanofibers and the incorporation of multiwalled carbon nanotubes (MWCNTs) to these materials. Scanning electron microscopy results confirmed the presence of polymer nanofibers, which showed a decrease in fiber diameter at 0.5% wt. and 1% wt. MWCNTs loadings, while transmission electron microscopy showed evidence of the MWCNTs embedded within the polymer matrix. The fourier transform infrared spectroscopy and Raman spectroscopy were used to elucidate the polymer-MWCNTs intermolecular interactions, indicating that the C-N and N-H bonds in polyurethanes are responsible for the interactions with MWCNTs. …

Design And Fabrication Of A Novel Electrospinning System For Musculoskeletal Tissue Regeneration, Carter L. Chain, Maggie R. Del Ponte, Meng Deng, Feng Yue, Shihuan Kuang

The Summer Undergraduate Research Fellowship (SURF) Symposium

Disease and injury to human tissue, especially musculoskeletal tissue, is a prevalent concern to the public, affecting millions of people each year. Current treatment options involving autografts and allografts are hindered by limited availability and risk of immunogenicity, respectively. In order to overcome these limitations, a transdisiplinary regenerative engineering strategy has emerged with a focus on the development of biomimetic scaffolds that closely mimic the properties of the native tissues. For example, the structure of muscle tissue is characterized by oriented muscle fibers. However, fabrication of aligned nanofiber structures that mimic the anisotropic organization of muscle presents significant engineering challenges. …

Biodegradable Electrospun Nanofibers Coated With Platelet-Rich Plasma For Cell Adhesion And Proliferation, Luis Diaz-Gomez, Carmen Alvarez-Lorenzo, Angel Concheiro, Maite Silva, Fernando Dominguez, Faheem A. Sheikh, Travis Cantu, Raj Desai, Vanessa L. Garcia, Javier Macossay-Torres

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Biodegradable electrospun poly(ε-caprolactone) (PCL) scaffolds were coated with platelet-rich plasma (PRP) to improve cell adhesion and proliferation. PRP was obtained from human buffy coat, and tested on human adipose-derived mesenchymal stem cells (MSC) to confirm cell proliferation and cytocompatibility. Then, PRP was adsorbed on the PCL scaffolds via lyophilization, which resulted in uniform sponge-like coating of 2.85 (s.d. 0.14) mg/mg. The scaffolds were evaluated regarding mechanical properties (Young’s modulus, tensile stress and tensile strain), sustained release of total protein and growth factors (PDGF-BB, TGF-β1 and VEGF), and hemocompatibility. MSC seeded on the PRP-PCL nanofibers showed an increased adhesion and proliferation …

Electrospinning Applications Air Filtration And Superhydrophobic Materials, Negar Ghochaghi, Adetoun Taiwo

Graduate Research Posters

Electrospinning is a widely applicable technique that generates non-woven fibers in the micro and nano range. In this project two of its applications are highlighted namely filtration media and enhancement of wettability. The first project demonstrates that electrospinning can be used to produce new fiber filtration media with controlled microstructure. The bimodal and unimodal orthogonal and random filters were made and characterized against their filtration efficiency and pressure drop. Figure of Merit (FOM) was also calculated and discussed. It is shown that the FOM increases when the electrospun fibers are arranged into alternating layers of aligned course and fine fibers. …

Experimental Development Of Advanced Air Filtration Media Based On Electrospun Polymer Fibers, Negar Ghochaghi

Theses and Dissertations

Electrospinning is a process by which polymer fibers can be produced using an electrostatically driven fluid jet. Electrospun fibers can be produced at the micro- or nano-scale and are, therefore, very promising for air filtration applications. However, because electrospun fibers are electrically charged, it is difficult to control the morphology of filtration media. Fiber size, alignment and uniformity are very important factors that affect filter performance. The focus of this project is to understand the relationship between filter morphology and performance and to develop new methods to create filtration media with optimum morphology.

This study is divided into three focus …

Experimental Study Of Nanofiber Production Through Forcespinning, Simon Padron, Arturo Fuentes, Dumitru Caruntu, Karen Lozano

Mechanical Engineering Faculty Publications

A newly developed method of producing nanofibers, called forcespinning, has proven to be a viable alternative to mass produce nanofibers. Unlike electrospinning, the most common method currently being employed (which draws fibers through the use of electrostatic force), forcespinning utilizes centrifugal forces which allow for a host of new materials to be processed into nanofibers (given that electric fields are not required) while also providing a significant increase in yield and ease of production. This work presents a detailed explanation of the fiber formation process. The study is conducted using high speed photography to capture the jet initiation process at …

Defining An Optimal Surface Chemistry For Pluripotent Stem Cell Culture In 2d And 3d, Michael Roy Zonca Jr.

Legacy Theses & Dissertations (2009 - 2024)

Surface chemistry is critical for growing pluripotent stem cells in an undifferentiated state. There is great potential to engineer the surface chemistry at the nanoscale level to regulate stem cell adhesion. However, the challenge is to identify the optimal surface chemistry of the substrata for ES cell attachment and maintenance. Using a high-throughput polymerization and screening platform, a chemically defined, synthetic polymer grafted coating that supports strong attachment and high expansion capacity of pluripotent stem cells has been discovered using mouse embryonic stem (ES) cells as a model system. This optimal substrate, N-[3-(Dimethylamino)propyl] methacrylamide (DMAPMA) that is grafted on 2D …

Fabrication Of Poly(Vinylidene Fluoride) (Pvdf) Nanofibers Containing Nickel Nanoparticles As Future Energy Server Materials, Faheem A. Sheikh, Travis Cantu, Javier Macossay-Torres, Hern Kim

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

In the present study, we introduce Poly(vinylidene fluoride) (PVDF) nanofibers containing nickel (Ni) nanoparticles (NPs) as a result of an electrospinning. Typically, a colloidal solution consisting of PVDF/Ni NPs was prepared to produce nanofibers embedded with solid NPs by electrospinning process. The resultant nanostructures were studied by SEM analyses, which confirmed well oriented nanofibers and good dispersion of Ni NPs over them. The XRD results demonstrated well crystalline feature of PVDF and Ni in the obtained nanostructures. Physiochemical aspects of prepared nano-structures were characterized for TEM which confirmed nanofibers were welloriented and had good dispersion of Ni NPs. Furthermore, the …

Microscopic And Spectroscopic Studies Of Thermally Enhanced Electrospun Pmma Micro- And Nanofibers, Sean Pelfrey, Travis Cantu, Michael R. Papantonakis, Duane L. Simonson, R. Andrew Mcgill, Javier Macossay-Torres

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Carbon nanofibers (CNFs) have been incorporated into poly(methyl methacrylate) (PMMA) through electrospinning. The resulting micro- and nanofibers have been characterized by Scanning Electron Microscopy (SEM), which confirmed fiber formation and demonstrated a core-sheath structure of the PMMA fibers. Thermogravimetric Analysis (TGA) was used to obtain the thermal properties of the materials, indicating an enhancement in the thermal properties of the composite fibers. In addition, Fourier Transform Infrared Spectroscopy (FTIR) was utilized to investigate the interactions of PMMA micro- and nanofibers with CNFs, demonstrating the preferred sites of intermolecular interactions between the polymer matrix and the filler.