A new solution-based matrix material for temperature sensors

This study presents a new environmentally friendly matrix material for temperature sensor applications. Sodium silicate solution and graphite were used as matrix and conductive materials, respectively. The chemical, morphological, and electrical properties of the raw materials and composites were investigated using X-ray diffractometer, Scanning Electron Microscope, Raman spectroscopy, Hall effect device, and digital multimeters. The effect of graphite content on the performance of sensors was investigated. All samples showed negative temperature coefficient (NTC) behaviour. The performance of sensors was investigated between 25 degrees C and 100 degrees C. The prepared sensors exhibited a linearity of 0.96, and a sensitivity of - 0.0479%/C-1. The sensors showed response and recovery time of 30 and 48 s, respectively. In addition, the sensors showed long-term stability, and repeatability with a very low percolation threshold (7.5 wt%). Finally, to demonstrate the functionality of sensors in practical applications, the paint-like composite solution was applied to a beaker surface and paper tape to monitor the performance of the sensor in real-time

Extrusion-Based 3D Printing of CuSn10 Bronze Parts: Production and Characterization

The interest in producing cost-effective 3D printed metallic materials is increasing day by day. One of these methods, which has gained much attention recently, is the fused deposition modelling (FDM) method. The parameters used in the FDM method have significant effects on the printed part properties. In this study, CuSn10 bronze alloy was successfully produced. The printing speed and layer thickness were investigated as the printing process parameters, and their effect on morphological properties was characterized by using SEM. As a result, it was observed that the formation of printing-induced voids was prevented by applying a layer thickness of 0.2 mm. Additionally, by increasing printing speed, a slight decrease in product density was observed. Following determination of 3D printing parameters which give the highest printed part density, the parts were debound in hexane solution via solvent debinding. Finally, the parts were sintered at 850, 875 and 900 & DEG;C for 5 h to examine effect of sintering temperature on density, porosity, shape deformation and mechanical properties. Although partial slumping started to form over 875 & DEG;C, the highest density (94.19% of theoretical density) and strength (212 & PLUSMN; 17.72 MPa) were obtained by using 900 & DEG;C as the sintering temperature

Characterization of a novel natural cellulosic fiber extracted from the stem ofChrysanthemum morifolium

Natural fiber reinforced green composites have been attracting high attention nowadays, as the green movement in the world forced companies to use green materials instead of synthetic fibre reinforced composites. In this respect, the aim of the study is to investigate usage possibility of undervaluedChrysanthemum morifoliumstem fibers as a new reinforcement of composite materials. Chemical, thermal, crystallographic, density, mechanical and morphological characterizations of theC. morifoliumfibers were examined.Crystallinity Index, density and tensile strength values were found as 65.18%, 1.33 g/cm(3)and 65.12 MPa, respectively.Chrysanthemum morifoliumhas a low cellulose content of 32.9% while the thermal resistance temperature was determined as 267.5 degrees C. Although its cellulose content is low,C. morifoliumfiber can be a good alternative for many other reinforcement plant fibers in terms of tensile strength. The high tensile strength of the fiber can be attributed to the high crystallinity index and fiber morphology advantage (low lumen diameter and thick cell wall). Hollow fiber morphology can increase the insulation and absorption properties of the fibers and can also create a usage area in lightweight composites by providing low density. This study suggests a novel sustainable ecological reinforcement fiber for green polymer composites with low density, reasonable tensile strength, high surface hydrophobicity and high surface roughness

Extraction and Characterization of Natural Cellulosic Fiber from Taraxacum Sect. Ruderalia

The aim is to explore the utilization of cellulosic fibers extracted from the Taraxacum Sect. Ruderalia, which is also known as dandelion, introduces a potential reinforcement for the green composite industry. This research is focused on the analysis of chemical, physical, thermal, and morphological properties of the Taraxacum Sect. Ruderalia fibers. Its lightweight (1.397 g/cm(3)) with the presence of an acceptable cellulose ratio (52.7%) and high crystallinity (69.59%) provide comparable tensile strength (57.36 MPa) and Young's modulus (2.96 GPa) for Taraxacum Sect. Ruderalia fibers. The fibers are experimentally thermal resistant to 272 degrees C according to TGA that may be profitable in extrusion processes in polymeric composite manufacturing. The average fiber diameter and wall thickness were optically 233 mu m and 1.5 mu m, respectively. Taraxacum Sect. Ruderalia fibers have a rough surface character with some irregularities such as porosities, particles, indentations, protrusions, and also the microfibrillar structure which can support mechanical interlocking with polymer in a composite system. With all these encouraging properties, Taraxacum Sect. Ruderalia fibers can be good alternative reinforcement for common cellulosic bast fibers in the development of ecologically friendly and sustainable polymeric-based materials