Enhancing the Thermal and Mechanical Properties of Organic-Inorganic Hybrid Nanocomposite Films Based on Poly Lactic Acid/OMMT Nano Clay

Abstract: Organic (PLA) inorganic (OMMT nano clay) hybrid nanocomposite films were fabricated using poly lactic acid (PLA) with various weight percentages (1-3wt%) of organically modified montmorillonite (OMMT) nano clay by means of one step solvent casting method. The thermal, mechanical and water absorption properties were determined as per standard testing methods to determine the optimum percentage of OMMT nano clay within the nanocomposite was investigated. The surface morphology of the organic-inorganic hybrid nanocomposite films was analyzed through XRD, SEM, and TEM surface analytical techniques. The incorporation of OMMT clay in to PLA matrix is found to have enhanced the thermo-mechanical properties. The water absorption and solubility test results also support the data from thermo-mechanical tests. The 2 wt % OMMT clay loaded PLA films showed the best results among all. The obtained results showed that the thermal, mechanical and water absorption properties could be increased significantly with the optimum incorporation of OMMT nano clay in a PLA matrix, in comparision wih the neat PLA

Green Nanosilver as Reinforcing Eco-Friendly Additive to Epoxy Coating for Augmented Anticorrosive and Antimicrobial Behavior

Epoxy resin GY250 representing diglycidyl ethers of bisphenol-A (DGEBA) was reinforced with 1, 3 and 5 wt % of surface functionalized silver nanoparticles (F-AgNPs) which were synthesized using Couroupita guianensis leaves extract with a view of augmenting the corrosion control property of the epoxy resin and also imparting antimicrobial activity to epoxy coatings on mild steel. Corrosion resistance of the coatings was evaluated by EIS, potentiodynamic polarization studies and cross scratch tests. AFM, SEM, HRTEM and EDX were utilized to investigate the surface topography, morphology and elemental composition of the coatings on MS specimens. Results showed that the corrosion resistance, hardness and T-g of the DGEBA/F-AgNPs coatings increased at 1 wt % of F-AgNPs. The DGEBA/F-AgNPs coatings also offered manifold antimicrobial protection to the MS surfaces by inhibiting the growth of biofilm forming bacteria like P. aeruginosa, B. subtilis, the most common human pathogen E. coli and the most virulent human pathogenic yeast C. albicans

Differential in vivo urodynamic measurement in a single thin catheter based on two optical fiber pressure sensors

Urodynamic analysis is the predominant method for evaluating dysfunctions in the lower urinary tract. The exam measures the pressure during the filling and voiding process of the bladder and is mainly interested in the contraction of the bladder muscles. The data arising out of these pressure measurements enables the urologist to arrive at a precise diagnosis and prescribe an adequate treatment. A technique based on two optical fiber pressure and temperature sensors with a resolution of better than 0.1 cmH2O (~10 Pa), a stability better than 1 cmH2O/hour, and a diameter of 0.2 mm in a miniature catheter with a diameter of only 5 Fr (1.67 mm), was used. This technique was tested in vivo on four patients with a real-time urodynamic measurement system. The optical system presented showed a very good correlation to two commercially available medical reference sensors. Furthermore, the optical urodynamic system demonstrated a higher dynamic and better sensitivity to detect small obstructions than both pre-existing medical systems currently in use in the urodynamic field

Novel miniature pressure and temperature optical fibre sensor based on an extrinsic Fabry-Perot Interferometer (EFPI) and Fibre Bragg Gratings (FBG) for the ocean environment

A novel miniature sensor is proposed for accurate measurement of pressure (depth) and temperature changes in the ocean environment. The sensor is based on an optical fibre extrinsic Fabry Perot interferometer (EFPI) combined with a Fibre Bragg Grating (FBG). The EFPI provides pressure measurements while the Fibre Bragg Grating (FBG) provides temperature measurements. The FGB is post-inscribed into the EFPI using a femtosecond laser. The sensor is mechanically robust, corrosion resistant and suitable for use underwater. The combined pressure and temperature sensor system was mounted on-board a mini remotely operated underwater vehicle (ROV) in order to monitor the pressure changes at varying depths and compare with the reference pressure-depth sensor. The reflected optical spectrum of the sensor was monitored online and a pressure change caused a corresponding observable shift in the optical spectrum. The sensor exhibited excellent stability when measured over a 2 hour period underwater and its performance is compared with a commercially available reference sensor also mounted on the ROV. The comparison illustrates that the EFPI/FBG sensor is more accurate (∼0.025m) with a resolution of ∼0.005m, when compared to the reference sensor.IEEE Sensors Council (SC

Novel miniature pressure and temperature optical fibre sensor based on an extrinsic Fabry-Perot Interferometer (EFPI) and Fibre Bragg Gratings (FBG) for the ocean environment

A novel miniature sensor is proposed for accurate measurement of pressure (depth) and temperature changes in the ocean environment. The sensor is based on an optical fibre extrinsic Fabry Perot interferometer (EFPI) combined with a Fibre Bragg Grating (FBG). The EFPI provides pressure measurements while the Fibre Bragg Grating (FBG) provides temperature measurements. The FGB is post-inscribed into the EFPI using a femtosecond laser. The sensor is mechanically robust, corrosion resistant and suitable for use underwater. The combined pressure and temperature sensor system was mounted on-board a mini remotely operated underwater vehicle (ROV) in order to monitor the pressure changes at varying depths and compare with the reference pressure-depth sensor. The reflected optical spectrum of the sensor was monitored online and a pressure change caused a corresponding observable shift in the optical spectrum. The sensor exhibited excellent stability when measured over a 2 hour period underwater and its performance is compared with a commercially available reference sensor also mounted on the ROV. The comparison illustrates that the EFPI/FBG sensor is more accurate (∼0.025m) with a resolution of ∼0.005m, when compared to the reference sensor.IEEE Sensors Council (SC

Fiber-optic technologies for advanced thermo-therapy applied ex vivo to liver tumors

Thermal ablation, using radiofrequency, microwave, and laser sources, is a common treatment for hepatic tumors. Sensors allow monitoring, at the point of treatment, the evolution of thermal ablation procedures. We present optical fiber sensors that allow advanced capabilities for recording the biophysical phenomena occurring in the tissue in real time. Distributed or quasi-distributed thermal sensors allow recording temperature with spatial resolution ranging from 0.1 mm to 5 mm. In addition, a thermally insensitive pressure sensor allows recording pressure rise, supporting advanced treatment of encapsulated tumors. Our investigation is focused on two case studies: (1) radiofrequency ablation of hepatic tissue, performed on a phantom with a stem-shaped applicator; (2) laser ablation of a liver phantom, performed with a fiber laser. The main measurement results are discussed, comparing the technologies used for the investigation, and drawing the potential for using optical fiber sensors for "smart"-ablation