Effects of some acids, bases and salts on the morphology of polyurethane nanofibres

The polyurethane nanofibres have been prepared by electrospinning and the effects of different types of acids, bases, and salts on nanofibre diameters within the polyurethane solutions are studied. Nanofibre diameters are measured with the SEM and the changes in nanofibre morphology are investigated by considering the electrical conductivity, viscosity, and surface tensions of dopants. Deterioration is observed in the nanofibre morphology in the presence of acid, whereas the nanofibres obtained in the presence of salt are found smoother, longer and thinner. Homogeneous, fine and smooth nanofibres are obtained from salt-doped polyurethane solutions

Effects of some acids, bases and salts on the morphology of polyurethane nanofibres

65-71The polyurethane nanofibres have been prepared by electrospinning and the effects of different types of acids, bases, and salts on nanofibre diameters within the polyurethane solutions are studied. Nanofibre diameters are measured with the SEM and the changes in nanofibre morphology are investigated by considering the electrical conductivity, viscosity, and surface tensions of dopants. Deterioration is observed in the nanofibre morphology in the presence of acid, whereas the nanofibres obtained in the presence of salt are found smoother, longer and thinner. Homogeneous, fine and smooth nanofibres are obtained from salt-doped polyurethane solutions

Applications of Cutting-Edge Biosensors in Healthcare and Biomedical Research

Biosensors are remarkable devices that convert biological reactions to chemical compounds into measurable signals, allowing for specific detection of target analytes. The classification of biosensors is based on the type of bioreceptor or transducer used. They have diverse applications in environmental monitoring, detection of toxins, pharmaceuticals, prosthetics, biotechnology, and biomedical engineering, with a crucial role in monitoring soil, water, and food quality. In the field of health and biomedicine, biosensors have undergone significant advancements in diagnosis and treatment of diseases by providing highly accurate results. This chapter focuses on the advancements and applications of biosensors in various biotechnological domains

Preparation and characterization of polyacrylic acid-hydroxyapatite nanocomposite by microwave-assisted synthesis method

Polyacrylic acid, polyalkenoic acids in general, form the liquid ionomer phase of glass ionomer cements, which are frequently used in root restorations in dentistry. It is possible to obtain these ionomers with a fast, energy-efficient, high reaction efficiency and a clean method with microwave irradiation method. In this study, polyacrylic acid and its composite with nano HAp have been synthesized by microwave (MW) irradiation. The two-process parameters that were tested are MW intensity and reaction time. The polymerization was carried out at 110 °C up to 40 min and yield over 92% was produced in 30 min. The average molar mass of PAA was found as 11960 Da using a high-resolution mass spectrometer (TOF-MS). On the other hand, hydroxyapatite (HAp) nanoparticles have been prepared via the sol-gel procedure using potassium dihydrogen phosphate and calcium nitrate tetrahydrate as the precursors for phosphorus and calcium, respectively. XRD, EDS analysis revealed that the particles contain calcium deficient hydroxyapatite (Ca10-x(HPO4)x(PO4)6-x(OH)2-x (HAp) crystals with beta-TCP phase. Morphological observation by SEM measurement proved that the crystal particles of the HAp are very regular and granular, and their size is 25–45 nm in the longitudinal section. These particles were used in composite preparation with PAA. The yield of the composite obtained by heating at 500 W, 30 min was found to be 90%. From the FTIR and 1H-NMR results, it was observed that there was not only a physical but also an electrostatic interaction between HAp and PAA. The thermal behavior of PAA and its composite with nano HAp were determined by the thermogravimetric analyzer (TGA). The results showed that anhydride formation or decarboxylation occurred at a lower temperature, confirming the interaction between PAA and HAp. The polymerization rate is much faster with microwave heating than conventional heating. Microwave irradiation enables rapid energy transfer and high-energy efficiency, hence, a faster reaction rate

Flexural stress enhancement of concrete by incorporation of algal cellulose nanofibers

WOS: 000405536800027Using nanofibers as a reinforcement material in the concrete and its positive effect on the concrete strength is one of the most popular topics in recent years. In the present study it was demonstrated that the nanofibers derived from waste algae (Cladophora sp) increased 2.7 times the flexural stress of the concrete. Firstly, the cellulose nanofibers were derived from Cladophora sp algae which stand in the nature as a waste and can be collected in tones. The obtained cellulose nanofiber and the commercial cellulose were characterized by Fourier Transform Infrared (FT-IR) Spectroscopy, Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray diffractometry (XRD) and Scanning Electron Microscopy (SEM) methods. Then, various amounts of the cellulose nanofiber and the commercial cellulose were added in the cement paste. Before the flexural stress tests, the concrete samples were left to dry for one week. Flexural stresses of the concrete samples were measured by the three-point bending test. The flexural stress of the control concrete sample (with no nanofibers) was measured as 2.21 MPa. The flexural stress of the concrete sample added 1.0 g cellulose nanofiber (derived from algae) were measured 5.96 MPa. On the other hand, it was determined that the commercial cellulose fibers decreased the flexural stress of the concrete samples. The used Cladophora sp algae in this study has a worldwide potential of extreme algal blooming in the aquatic ecosystems and the algal blooming of Cladophora sp causes to eutrophication of water sources. In this study it was proven that removing of algal mats from nature and using them as a reinforced material in concrete can be wisely solution instead of the synthetic cement paste additives. (C) 2017 Elsevier Ltd. All rights reserved

Effect of Sonic Treatment on The Permeation Performance of Cellulose Acetate Membranes Modified By N-Sio2

Cellulose acetate (CA) membranes were modified by nano-silicon dioxide (n-SiO2), and they were exposed to ultrasonic waves at a frequency of 35 kHz. The effect of sonication on their water sorption tendency and permeation capability was investigated. The characterization of the membranes was done by FTIR and SEM analysis, and the hydrophilic character of the membranes was deduced by swelling studies and contact angle (CAn) measurements. Permeation studies of the membranes were performed by using the diffusion method and theophylline was used as a model chemical in the permeation studies. The results indicated that beside the high hygroscopic property of n-SiO2 the presence of n-SiO2 in CA membranes did not significantly improve their hydrophilicity; however, when they were exposed to sonic waves, it was determined that the sonication effectively enhanced their water sorption capacity and permeability.WoSScopu