Advances in Nanofibers

Book Advances in Nanofibers is a research publication that covers original research on developments within the Nanofibers field of study. The book is a collection of reviewed scholarly contributions written by different authors. Each scholarly contribution represents a chapter and each chapter is complete in itself but related to the major topics and objectives. The target audience comprises scholars and specialists in the field

Polymer nanoparticles and nanofibers: Drug delivery and environmental applications

Since \u201cnanotechnology\u201d was presented by Nobel laureate Richard P. Feynman during his well famous 1959 lecture \u201cThere\u2019s Plenty of Room at the Bottom\u201d, there have been made various revolutionary developments in the field of nanotechnology. However, nanotechnology has emerged in the last decade as an exciting new research field. Nanotechnology represents the design, production, and application of materials at atomic, molecular and macromolecular scales, in order to produce new nanosized structures where at least one dimension is of roughly 1 to 100 nm, i.e., less than 0.1 \u3bcm. However, materials below or next to 1 \u3bcm (1000 nm) can be also commonly referred as nanomaterials or, more correctly, ultrathin materials. According to this, specifically within fiber science related literature, fibers with diameters below 1 \u3bcm are broadly accepted as nanofibers. Nanotechnology and nanoscience studies have emerged rapidly during the past years in a broad range of product domains. Today, nanoscience represents one of the rapidly growing scientific disciplines due to its enormous potential and impact in many different technological and engineering applications, which includes the development of new materials with novel and advanced performances. Recently, the nano-scaled materials have attracted extensive research interests due to their high anisotropy and huge specific surface area. Furthermore, the continuously increasing interest in the nanostructure materials results from their numerous potential applications in various areas, particularly in biomedical sciences. Today, nanofibers and nanoparticles are at the forefront of nanotechnology because of their unique properties such as low density, extremely high surface area to volume ratio, flexibility in surface functionalities, superior mechanical performance (e.g. stiffness and tensile strength), and high pore volume and controllable pore size that cannot be found in other structures. In this context, our researches have been concentrated on the production and modification of polymeric nanofibers and nanoparticles as drug delivery and environment applications. To this purpose, selected materials for the nanofibers development (polyhedral oligomeric silsesquioxanes, modified poly(amido-amine) dendrimers, and modified hyperbranched polyglycerol) were combined with biopolymers, namely (poly(L-lactide) (PLLA) and poly(\u3b5-caprolactone) (PCL) which enable us to overcome typical shortcomings of the above polymer matrices. As well, poly(styrene-co-maleic anhydride) (PSMA) amphiphilic copolymer was used for production of nanoparticles

21st Century Nanostructured Materials

Nanostructured materials (NMs) are attracting interest as low-dimensional materials in the high-tech era of the 21st century. Recently, nanomaterials have experienced breakthroughs in synthesis and industrial and biomedical applications. This book presents recent achievements related to NMs such as graphene, carbon nanotubes, plasmonic materials, metal nanowires, metal oxides, nanoparticles, metamaterials, nanofibers, and nanocomposites, along with their physical and chemical aspects. Additionally, the book discusses the potential uses of these nanomaterials in photodetectors, transistors, quantum technology, chemical sensors, energy storage, silk fibroin, composites, drug delivery, tissue engineering, and sustainable agriculture and environmental applications

Synthesis, engineering and development of nano/micro antibacterial composites for drug delivery

Antibiotic resistance is one of the greatest health concerns worldwide. Data shows within the last 50 years, the number of species and strains of pathogenic and commensal bacteria resistant to antibiotics, has increased virtually monotonically worldwide. Research presented here shows successful synthesis of polymeric drug composites for antibacterial drug delivery, using the electro hydrodynamic atomization technique (EHDA). A biodegradable polymer poly (lactic-co-glycolic acid) (PLGA) proved to be suitable for sustained drug delivery. Materials added to the polymeric composites included the active agent amoxicillin (AMX) and metallic nanoparticles varying in size and morphology. Upon successful synthesis, the drug release, antibacterial efficacy and cell culture data, collated, confirmed the EHDA process is a good alternative method for synthesising antibacterial composite formulations. It is an easy one step process, regardless of the number of excipients added, and also allows for encapsulation of poorly soluble drugs. The first step was to synthesise metallic nanoparticles; varying in shape and size, this would help determine if differences in shape and size of nanoparticles will have an effect on drug content and release data, as well as antibacterial efficacy. Therefore, three types of metals were chosen for their varying antibacterial activity; silver, gold and copper. Silver was synthesised varying in shape and size, including spherical, wire and polygonal or edged. Upon successful synthesis, the next step was to formulate suspensions, made up of PLGA and AMX, along with the varying metallic nanoparticles to electrospray. Two different solvents were used acetone and dichloromethane (DCM), the varying differences in characteristic qualities like electrical conductivity and viscosity, allowed for determination of a stable spray. Results showed the best solvent to use between the two was acetone due to a much higher electrical conductivity and lower viscosity. Thereafter, the composite samples collected were analysed. Drug loading for the formulation containing PLGA and AMX (F2) only was 1.18%, but with the addition of different metallic nanoparticles it increased up to 2.57%. Drug release for F2 was at 18.6% and increased up to 56.1% depending on metallic nanoparticle added. Metallic nanoparticles exhibit antibacterial efficacy, with AgNPs showing the greatest antibacterial activity, confirmed through disk diffusion zone sizes. Antibacterial activity enhancement was proved by formulations containing silver nanoparticles, showing increased activity against S. aureus through increased disk diffusion zones compared to using AMX and silver nanoparticles on their own. AgNPs against S. aureus gave an average inhibition zone of 18.8 mm when compared to CuNP which only gave an average inhibition zone size of 16.07mm. Full formulation containing PLGA AMX and edge shaped silver nanoparticles (F5) proved to have the highest antibacterial efficacy when compared to the other formulations. This was explained through an increase in surface area to volume ratio of the silver nanoparticles, when compared to the spherical and wire shaped nanoparticles. Cell culture data namely the MTT assay also showed (F5) had a cell viability of 71%, this displays promising signs for this formulation for future use as an antibacterial agent

Preparation, Physico-Chemical Properties and Biomedical Applications of Nanoparticles

Nowadays, the impact of nanotechnology on applications in medicine and biomedical sciences has broader societal and economic effects, enhancing awareness of the business, regulatory, and administrative aspects of medical applications. The selected papers included in the present Special Issue gives readers a critical, balanced and realistic evaluation of existing nanomedicine developments and future prospects, allowing practitioners to plan and make decisions.The topics of this book covers the use of nanoparticles and nanotechnology in medical applications including biomaterials for tissue regeneration, diagnosis and monitoring, surgery, prosthetics, drug delivery systems, nanocarriers, and wound dressing. I would like to express my gratitude to all contributors to this issue, who have given so much of their time and effort to help create this collection of high quality papers

Chapter 34 - Biocompatibility of nanocellulose: Emerging biomedical applications

Nanocellulose already proved to be a highly relevant material for biomedical applications, ensued by its outstanding mechanical properties and, more importantly, its biocompatibility. Nevertheless, despite their previous intensive research, a notable number of emerging applications are still being developed. Interestingly, this drive is not solely based on the nanocellulose features, but also heavily dependent on sustainability. The three core nanocelluloses encompass cellulose nanocrystals (CNCs), cellulose nanofibrils (CNFs), and bacterial nanocellulose (BNC). All these different types of nanocellulose display highly interesting biomedical properties per se, after modification and when used in composite formulations. Novel applications that use nanocellulose includewell-known areas, namely, wound dressings, implants, indwelling medical devices, scaffolds, and novel printed scaffolds. Their cytotoxicity and biocompatibility using recent methodologies are thoroughly analyzed to reinforce their near future applicability. By analyzing the pristine core nanocellulose, none display cytotoxicity. However, CNF has the highest potential to fail long-term biocompatibility since it tends to trigger inflammation. On the other hand, neverdried BNC displays a remarkable biocompatibility. Despite this, all nanocelluloses clearly represent a flag bearer of future superior biomaterials, being elite materials in the urgent replacement of our petrochemical dependence

Magnetic Nanomaterials

The constant search for innovative magnetic materials increasingly leads to the creation of highly engineered systems built in different forms (films, wires, particles), structured on the nanoscale in at least one spatial direction, and often characterized by the coexistence of two or more phases that are magnetically and/or structurally different. In magnetic systems, the nanometric structural characteristics of the constituent elements, together with the type and strength of the magnetic interactions between them, determine the overall magnetic behavior and can lead to the appearance of unexpected and amazing magnetic phenomena. Indeed, the study of the magnetic properties of nanomaterials continues to arouse great interest for their intriguing fundamental properties and prospective technological applications. This Special Issue contributes to broadening the knowledge on magnetic nanomaterials, demonstrating the breadth and richness of this research field as well as the growing need to address it through an interdisciplinary approach. The papers collected in this book (two reviews and eight regular articles) report cutting-edge studies on the production and characterization of a variety of novel magnetic nanomaterials (nanoparticles, nanocomposites, thin films and multilayers), which have the potential to play a key role in different technologically advanced sectors, such as biotechnology, nanomedicine, energy, spintronics, data storage, and sensors

Functional Nanomaterials and Polymer Nanocomposites: Current Uses and Potential Applications

This book covers a broad range of subjects, from smart nanoparticles and polymer nanocomposite synthesis and the study of their fundamental properties to the fabrication and characterization of devices and emerging technologies with smart nanoparticles and polymer integration

Synthesis of sulphonated and transition metal oxide doped polymeric nanocomposites for application in design of supercapacitors

Philosophiae Doctor - PhDTo meet a fast-growing market demand for next generation portable electronic devices with higher performance and increased device functionalities, efficient electrical energy devices with substantially higher energy, power densities and faster recharge times such as supercapacitors are needed. The overall aim of this thesis was to synthesize nanostructured sulphonated polyaniline and transition metal single, binary and ternary mixed oxide doped nanocomposites with electro-conductive properties. These nanocomposites were anchored on activated graphitic carbon and used in design of asymmetric supercapacitors. Tantalum(IV)oxide, tantalum(IV)oxide-nickel(II)oxide, tantalum(II)oxide-manganese(III)oxide, tantalum(II)oxide-nickel(II)oxide-manganese(II,III)oxide nanoparticles were synthesised using modified sol-gel methods. These were then dispersed, individually, in acidic media through sonication and incorporated in-situ into the polymeric matrix during the oxidative chemical polymerization of aniline doped with poly(4-styrene sulphonic acid). These novel polymeric nanocomposites were characterised with FTIR, UV-visible, TEM, SEM, EDS, XRD to ascertain successful polymerization, doping, morphology and entrapment of the metal oxide nanoparticles. SECM approach curves and interrogation of CV revealed that these nanocomposites are conductive and electro-active. The cells showed good supercapacitor characteristics with high specific capacitances of 170.5 Fg⁻¹ in TaO₂- PANi-PSSA, 166.1 Fg⁻¹ in TaO₂-NiO-PANi-PSSA, 248.4 Fg-1 in TaO-Mn₂O₃-PANi- PSSA and 119.6 Fg⁻¹ in TaO-NiO-Mn₃O₄-PANi-PSSA. Their corresponding energy densities were calculated as 245.5 Whg⁻¹, 179.4 Whg⁻¹, 357.7 Whg⁻¹ and 172.3 Whg⁻¹ respectively. They also gave respective power densities of 0.50 Whg⁻¹, 0.61 Whg⁻¹, 0.57 Whg⁻¹ and 0.65 Whg⁻¹ and showed good coulombic efficiencies ranging between 77.97% and 83.19%. These materials are found to have a long cycle life and therefore good electrode materials for constructing supercapacitor cells.National Research Foundation (NRF

Preparation of Quasi-Three-Dimensional Porous Ag and Ag-NiO Nanofibrous Mats for SERS Application

In this study, two new quasi-three-dimensional Surface Enhanced Raman Scattering (SERS) substrates, namely porous Ag and Ag-NiO nanofibrous mats, were prepared using a simple, electrospinning-calcination, two-step synthetic process. AgNO3/polyvinyl pyrrolidone (PVP) and AgNO3/Ni(NO3)2/PVP composites serving as precursors were electrospun to form corresponding precursory nanofibers. Porous Ag and Ag-NiO nanofibers were successfully obtained after a 3-h calcination at 500 °C under air atmosphere, and analyzed using various material characterization techniques. Synthesized, quasi-three-dimensional porous Ag and Ag-NiO nanofibrous mats were applied as SERS substrates, to measure the model compound Rhodamine 6G (R6G), and investigate the corresponding signal enhancement. Furthermore, porous Ag and Ag-NiO nanofibrous mats were employed as SERS substrates for melamine and methyl parathion respectively. Sensitive detection of melamine and methyl parathion was achieved, indicating their feasibility as an active SERS sensing platform, and potential for food safety and environmental monitoring. All the results suggest that the electrospinning-calcination, two-step method offers a new, low cost, high performance solution in the preparation of SERS substrates