Piezoresistive pressure sensors have been prepared by the electrospinning of poly(vinylidene fluoride) (PVDF) containing graphene nanoplatelets (GNP) functionalized using 1-butyl-3-methylimidazolium trifluoromethanesulfonate (BMIM(OTf)) ionic liquid (IL). Optical microscopy demonstrated that the functionalized GNP powder presented particles with a smaller lateral size. The obtained mats were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, differential scanning calorimetry, electrical resistivity using two and four probes, and electromechanical testing with up to 32 load-unload cycles.
View Article and Find Full Text PDFFunctionally active aligned fibers are a promising approach to enhance neuro adhesion and guide the extension of neurons for peripheral nerve regeneration. Therefore, the present study developed poly(lactic--glycolic acid) (PLGA)-aligned electrospun mats and investigated the synergic effect with carbon nanotubes (CNTs) and Choline Bitartrate ionic liquid (Bio-IL) on PLGA fibers. Morphology, thermal, and mechanical performances were determined as well as the hydrolytic degradation and the cytotoxicity.
View Article and Find Full Text PDFTo protect crops as well as human and animal health, the development of novel repellents based on biopolymers is critical for a growing world population. Here, novel aphid-repellent electrospun mats containing epoxidized ionic liquids (ILs) covalently bonded to the carboxyl or hydroxyl groups of poly(lactic acid) (PLA) were designed to produce nonwoven mats. First, di-, tri-, and tetra-epoxidized imidazolium ILs were synthesized and incorporated in different weight fractions (3, 5, and 10 wt %) into the PLA solution.
View Article and Find Full Text PDFIn this study, we set out to modify poly(lactic acid) (PLA) by incorporating epoxidized ionic liquids (ILs) that were specifically designed with imidazolium-NTf moieties. First, we synthesized di-, tri- and tetra-epoxidized ILs, which were incorporated into a PLA matrix at 3, 5, and 10 wt% through a melt extrusion process. We investigated the relationship between the structure and properties of the resulting materials in terms of thermal, mechanical, rheological, and surface properties.
View Article and Find Full Text PDFPeripheral nerve injuries affect the quality of life of people worldwide. Despite advances in materials and processing in recent decades, nerve repair remains a challenge. The autograft is considered the most effective nerve repair in cases of serious injuries in which direct suture is not applied.
View Article and Find Full Text PDFPurpose: Placenta previa is a major cause of maternal morbidity and mortality, associated to a high risk of peripartum hemorrhage and hysterectomy. We aimed to verify if prophylactic intraoperative uterine artery embolization in patients with placenta previa and at least one additional risk of bleeding (major placenta previa), can reduce hemorrhage, need for blood transfusions, peripartum hysterectomy and maternal morbidity.
Materials And Methods: We enrolled 76 patients with major placenta previa; a specific multidisciplinary protocol was designed for management, including ultrasound evaluation, hospitalization at 34 weeks, antenatal corticosteroids and scheduled cesarean section at 35-36 weeks.
A thermally stable carbocationic covalent organic network (CON), named RIO-70 was prepared from pararosaniline hydrochloride, an inexpensive dye, and triformylphloroglucinol in solvothermal conditions. This nanoporous organic material has shown a specific surface area of 990 m g and pore size of 10.3 Å.
View Article and Find Full Text PDFMembranes for guided bone regeneration represent valuable resources, preventing fibroblast infiltration and aiding anatomical bone reconstruction. Nonetheless, available membranes lack bone regenerative capacity, suitable mechanical behavior, or adequate degradation profile. Therefore, to overcome these limitations, this study developed bilayer membranes with a dense layer (dry phase inversion) of PLGA (poly(lactic-co-glycolic acid)):HAp (hydroxyapatite) - 95:05 (wt%) - and an electrospun layer of PLGA and HAp:β-TCP (β-tricalcium phosphate) with ratios of 60:40, 70:30 and 85:15 (wt%), evaluating its mechanical, morphological and in vitro properties.
View Article and Find Full Text PDFMater Sci Eng C Mater Biol Appl
October 2019
Commercially, there are several plates and screws for bone fracture fixation made with PLA, however, its long degradation time and lack of integration with bone structure, provides interest in research using polymers with faster degradation, such as PLGA, and together with bioceramics, in order to improve bioactivity in bone regeneration. Based on this, in this study, bone fracture fixation plates composed of PLGA polymer matrix and combinations of 5 and 10%wt. of bioceramics were processed by microinjection.
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