Synthesis, characterization, and potential application of highly chemically durable glasses based on AlF3

1991 ◽  
Vol 6 (2) ◽  
pp. 401-406 ◽  
Author(s):  
Tariq Iqbal ◽  
Mahmoud R. Shahriari ◽  
Glenn Merberg ◽  
George H. Sigel

Fluorozirconate glasses are stable with respect to devitrification but have poor chemical durability and only fair mechanical strength. AlF3-based glasses with improved chemical durability and enhanced mechanical strength are reported here. The optical, mechanical, and thermal properties of these glasses are contrasted to the more familiar ZBLAN composition. The infrared edge of these glasses lies at shorter wavelengths than ZrF4-based glasses, but aluminum fluoride glasses offer some interesting opportunities for short-range IR fiber applications such as sensing, remote spectroscopy, and laser power propagation.

1989 ◽  
Vol 172 ◽  
Author(s):  
Mahmoud R. Shahriari ◽  
Tariq Iqbal ◽  
Paul R. Foy ◽  
Steve J. Saggese ◽  
G. H. Sigel

AbstractSeveral glass systems based on AIF3 have been synthesized and fabricated into preforms by controlled melting and rotational casting. High optical quality preforms have been drawn into fibers using a specially modified drawing facility. The drawing tower is enclosed with a vertical glove box in which the levels of both moisture and oxygen are kept below 1 ppm during the drawing. The AIF3 -based fibers have shown dramatically superior chemical durability relative to the ZrF4 -based glass fibers. Selected optical, mechanical and thermal properties of these fibers will be presented. AIF3 -based glass fibers offer interesting opportunities for short range applications in the 2–4 micron region of the infrared such as sensing, remote spectroscopy and laser power delivery.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3047 ◽  
Author(s):  
Young Shin Kim ◽  
Jae Kyung Kim ◽  
Euy Sik Jeon

Among the composite manufacturing methods, injection molding has higher time efficiency and improved processability. The production of composites via injection molding requires a pre-process to mix and pelletize the matrix polymer and reinforcement material. Herein, we studied the effect of extrusion process conditions for making pellets on the mechanical and thermal properties provided by injection molding. Polyamide 6 (PA6) was used as the base, and composites were produced by blending carbon fibers and Al2O3 as the filler. To determine the optimum blending ratio, the mechanical properties, thermal conductivity, and melt flow index (MI) were measured at various blending ratios. With this optimum blending ratio, pellets were produced by changing the temperature and RPM conditions, which are major process variables during compounding. Samples were fabricated by applying the same injection conditions, and the mechanical strength, MI values, and thermal properties were measured. The mechanical strength increased slightly as the temperature and RPM increased, and the MI and thermal conductivity also increased. The results of this study can be used as a basis for specifying the conditions of the mixing and compounding process such that the desired mechanical and thermal properties are obtained.


Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5641
Author(s):  
Ruxandra-Elena Geanaliu-Nicolae ◽  
Ecaterina Andronescu

Due to their unique properties—the are biocompatible, easily accessible, and inexpensive with programmable properties—biopolymers are used in pharmaceutical and biomedical research, as well as in cosmetics and food. Collagen is one of the most-used biomaterials in biomedicine, being the most abundant protein in animals with a triple helices structure, biocompatible, biomimetic, biodegradable, and hemostatic. Its disadvantages are its poor mechanical and thermal properties and enzymatic degradation. In order to solve this problem and to use its benefits, collagen can be used blended with other biomaterials such as alginate, chitosan, and cellulose. The purpose of this review article is to offer a brief paper with updated information on blended collagen-based formulations and their potential application in biomedicine.


2015 ◽  
Vol 763 ◽  
pp. 41-46
Author(s):  
Dana Koňáková ◽  
Eva Vejmelková

This article is focused on SCM questions. Studied material - metashale belongs among artificial pozzolana with natural origin. Shale is clay mineral and by its burning at 700°C similar material as metakaolin arises. Metashale is used as cement replacement up to 60% in concrete production. By means of measurement of basic physical properties, mechanical strength and thermal characteristic the effect of metashale is determined. Concrete containing 20% of metashale shows improvement of studied properties except of thermal conductivity. The 40% of the SCM leads to concrete production with same properties as the reference concrete. And when 60% of the burnt clay is utilized, final values of studied properties shows little deteriorations. However all studied materials shows appropriate properties to be applicable in civil engineering branch as load-bearing concrete.


2019 ◽  
pp. 089270571987822
Author(s):  
Saud Aldajah ◽  
Mohammad Y Al-Haik ◽  
Waseem Siddique ◽  
Mohammad M Kabir ◽  
Yousef Haik

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.


2019 ◽  
Vol 45 (12) ◽  
pp. 15596-15602 ◽  
Author(s):  
Xinlei Gu ◽  
Lina Yang ◽  
Xiaorong Ma ◽  
Xuan Dai ◽  
Jia Wang ◽  
...  

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