Physico-Chemical Properties and Valorization of Biopolymers Derived from Food Processing Waste

The widespread use of synthetic plastics, as well as the waste produced at the end of their life cycle, poses serious environmental issues. In this context, bio-based plastics, i.e., natural polymers produced from renewable resources, represent a promising alternative to petroleum-based materials. One potential source of biopolymers is waste from the food industry, the use of which also provides a sustainable and eco-friendly solution to waste management. Thus, the aim of this work concerns the extraction of polysaccharide fractions from lemon, tomato and fennel waste. Characterizing the chemical–physical and thermodynamic properties of these polysaccharides is an essential step in evaluating their potential applications. Hence, the solubility of the extracted polysaccharides in different solvents, including water and organic solvents, was determined since it is an important parameter that determines their properties and applications. Also, acid-base titration was carried out, along with thermoanalytical tests through differential scanning calorimetry. Finally, the electrospinning of waste polysaccharides was investigated to explore the feasibility of obtaining polysaccharide-based membranes. Indeed, electrospun fibers are a promising structure/system via which it is possible to apply waste polysaccharides in packaging or well-being applications. Thanks to processing feasibility, it is possible to electrospin waste polysaccharides by combining them with different materials to obtain porous 3D membranes made of nanosized fibers

OPTIMASI KONDISI LARUTAN DAN PARAMETER PROSES PEMINTALAN ELEKTRIK PADA SINTESIS SERAT NANO KITOSAN-PEO

Serat nano kitosan telah berhasil dibuat dengan penambahan polietilen oksida (PEO) sebagai polimer sekunder pada kondisi larutan dan parameter proses pemintalan elektrik yang optimum. Pada penelitian ini, larutan polimer kitosan/PEO pada berbagai konsentrasi (3,2, 3,6, dan 4 wt%) dan rasio (3:2 dan 1:1) dipintal secara elektrik (electrospinning) untuk memperoleh serat dengan morfologi paling baik. Selain kondisi larutan, parameter proses pintal elektrik yang penting seperti tegangan, laju alir umpan, dan jarak antara jarum dengan kolektor juga disesuaikan untuk mendapatkan proses dengan kondisi jet polimer yang stabil. Serat nano yang terbaik yakni tanpa butiran polimer (polymer microspheres) dan minim jumlah manik-manik (beads) berhasil diperoleh pada konsentrasi kitosan/PEO 4 wt% dan rasio 3:2. Parameter proses yang digunakan untuk mendapatkan serat ini yaitu tegangan 30 kV, laju alir umpan 0,3 ml/jam, dan jarak antara jarum dan kolektor 30 cm. Karakterisasi morfologi serat dari setiap eksperimen dilakukan dengan menggunakan mikroskop Phenom. Selanjutnya, serat nano terbaik yang diperoleh dikarakterisasi dengan menggunakan SEM dan diameter rata-rata serat diukur dengan aplikasi ImageJ. Hasil menunjukkan bahwa serat nano yang dihasilkan pada kondisi optimum memiliki diameter rata-rata 68 nm dan distribusi ukuran diameter serat tersebar cukup lebar mulai dari 30-150 nm.

Eumelanin 3D architectures: Electrospun PLA fiber templating for mammalian pigment microtube fabrication

Eumelanin 3D Architectures: Electrospun PLA Fiber Templating for Mammalian Pigment Microtube Fabricatio

Preparation of chitosan-based nanofiber mats containing Soluplus® as a potential polymeric carrier by electrospinning process

A preparation of chitosan-based nanofiber mats loaded with Soluplus as a novel carrier polymer was carried out. Soluplus, a water-soluble amphiphilic copolymer, was added to provide a nanofiber structure that will be useful in applications as drug delivery system. In this study, a mixture of chitosan, polyethylene oxide (PEO), and Soluplus micelles was electrospun into nanofibers and characterized using SEM to observe the fiber morphology. Rhodamine (Rh) was used as a model molecule trapped inside Soluplus micelles. The results showed that chitosan-based nanofiber mats were successfully realized by electrospinning of the chitosan/PEO polymer blend solution at a ratio of 3:2 with 4 wt% total polymer concentration. The optimum electrospinning parameters to obtain the nanofibers were at 30 kV electrical potential, 0.2 ml/hour feed rate, and 30 cm distance between the needle tip and the collector. The addition of Soluplus at four times greater critical micelles concentration (CMC) was still able to provide smooth and bead-less nanofibers morphology. Nanofiber mats with Rh-Soluplus have an average fiber diameter of 56 nm, a slightly thinner than the nanofibers with chitosan/PEO alone (63 nm). A preliminary study of Rh release from Soluplus micelles, as well as from Soluplus loaded in the nanofiber mats, showed slower release of Rh from Soluplus loaded in the nanofiber mats compared to the free Soluplus

New Insights to Design Electrospun Fibers with Tunable Electrical Conductive–Semiconductive Properties

Fiber electronics, such as those produced by the electrospinning technique, have an extensive range of applications including electrode surfaces for batteries and sensors, energy storage, electromagnetic interference shielding, antistatic coatings, catalysts, drug delivery, tissue engineering, and smart textiles. New composite materials and blends from conductive–semiconductive polymers (C-SPs) offer high surface area-to-volume ratios with electrical tunability, making them suitable for use in fields including electronics, biofiltration, tissue engineering, biosensors, and “green polymers”. These materials and structures show great potential for embedded-electronics tissue engineering, active drug delivery, and smart biosensing due to their electronic transport behavior and mechanical flexibility with effective biocompatibility. Doping, processing methods, and morphologies can significantly impact the properties and performance of C-SPs and their composites. This review provides an overview of the current literature on the processing of C-SPs as nanomaterials and nanofibrous structures, mainly emphasizing the electroactive properties that make these structures suitable for various applications

Electro Fluid Dynamics: A Route to Design Polymers and Composites for Biomedical and Bio-Sustainable Applications

In the last two decades, several processes have been explored for the development of micro and/or nanostructured substrates by sagely physically and/or chemically manipulating polymer materials. These processes have to be designed to overcome some of the limitations of the traditional ones in terms of feasibility, reproducibility, and sustainability. Herein, the primary aim of this work is to focus on the enormous potential of using a high voltage electric field to manipulate polymers from synthetic and/or natural sources for the fabrication of different devices based on elementary units, i.e., fibers or particles, with different characteristic sizes—from micro to nanoscale. Firstly, basic principles and working mechanisms will be introduced in order to correlate the effect of selected process parameters (i.e., an applied voltage) on the dimensional features of the structures. Secondly, a comprehensive overview of the recent trends and potential uses of these processes will be proposed for different biomedical and bio-sustainable application areas

Eumelanin coating of silica aerogel by supercritical carbon dioxide deposition of a 5,6-Dihydroxyindole thin film

Eumelanin integration in silica aerogel (SA) was achieved via supercritical adsorption of 5,6-dyhydroxyindole (DHI) from CO2. Notably, after the supercritical treatment, DHI evolved towards spontaneous polymerization, which resulted in uniform pigment development over the SA. The new material was characterized for its morphological and physicochemical properties, disclosing the formation of a eumelanin-like coating, as confirmed by UV–vis and electron paramagnetic resonance (EPR) spectroscopy

Poly(vinyl chloride)/CaCO3 nanocomposites: Influence of surface treatments on the properties

Poly(vinyl chloride) (PVC)-based nanocomposites containing calcium carbonate nanoparticles (CaCO3) were prepared. Different nanoparticle surface modifiers were selected and tested to promote matrix/filler interactions and, consequently, to obtain high- performance materials. In particular, the nanoparticles were modified with poly(acrylic acid) (PAA) and poly (butadiene-co-acrylonitrile-co-acrylic acid) (PBAA). For comparison, PVC-based materials, with the addition of commercial neat and stearic acid modified CaCO3, were also prepared. The influence of CaCO3 and surface modifiers on the gelation, thermal properties, thermal stability, and mechanical properties of PVC was studied. The gelation time of the rigid PVC/CaCO3 composites decreased as a function of the percentage and surface treatment of CaCO3. Morphological analysis proved the effectiveness of PAA and PBAA as surface modifiers; they obtained for the corresponding materials a typical nanostructured morphology. A significant improvement in the PVC thermal stability was recorded with the addition of neat and stearic acid modified CaCO3. Finally, mechanical tests showed an increase in the flexural strength and toughness of PVC as a function of the nanoparticle surface modifier. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 201

Effect of compatibilization on thermal degradation kinetics of HDPE-based composites containing cellulose reinforcements

Dynamic thermogravimetric analysis under nitrogen flow was used to investigate the thermal decomposition process of high-density poly(ethylene) (HDPE)-based composites reinforced with cellulose fibers obtained from the recycling of multilayer carton scraps, as a function of the cellulose content and the compatibilization. The Friedman, Flynn–Wall–Ozawa, and Coats–Redfern methods were used to determine the apparent activation energy (E a) of the thermal degradation of the cellulose component into the composites. E a has been found dependent on the cellulose amount and on the cellulose/polymer matrix interfacial adhesion. In particular, it has been evidenced an increase of the cellulose thermal stability as a consequence of the improved interfacial adhesion between the components in NFR composites