Effect of Slurry Formulation on Morphology and Flowability of Spray-Dried Alumina/Zirconia Composite Particles

2016 ◽  
Vol 675-676 ◽  
pp. 531-534 ◽  
Author(s):  
Saowaluk Chiangka ◽  
Sukasem Watcharamaisakul ◽  
Boris Golman
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Biomedical Applications ◽  
Solid Content ◽  
Composite Particles ◽  
Round Shape ◽  
Compressibility Index ◽  
Tap Density ◽  
Binder Type ◽  
Spray Dried

Alumina/zirconia composite materials are widely used for biomedical applications because of their high biocompatibility and good mechanical properties. In this work, the effects of slurry solid content and binder type are studied on the characteristics of spray-dried composite particles. The tap density and particle size of composite particles increase while the compressibility index decreases with increasing solid content of slurry. An analysis of the SEM micrographs of spray-dried particles confirms the formation of dense composite particles of round shape without internal holes with 70 wt.% slurry using PVA+PEG co-binder.

Study on Surface Sizing of Cationic Polyacrylate Emulsion to Improve Mechanical Properties of Paper

2012 ◽  
Vol 200 ◽  
pp. 287-291 ◽  
Author(s):  
Quan Xiao Liu ◽  
Wen Cai Xu ◽  
Yan Na Yin
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Positive Charge ◽  
Solid Content ◽  
Drying Methods ◽  
Machine Direction ◽  
Surface Sizing ◽  
Emulsion Layer ◽  
Folding Endurance ◽  
Tearing Strength

Cationic polyacrylate emulsion was used as surface sizing agent and the effects of emulsion properties on paper mechanical properties were studied. The mechanical properties of sized paper gradually increased with the increase of solid content, viscosity and positive charge density of emulsion and decreased with the increase of particle size of emulsion. Tensile strength, folding endurance and tearing strength on machine direction were increased 33.62%, 11.99%, 6.79% respectively when the paper with single emulsion layer was used oven drying methods.

Microstructures and Mechanical Properties of Three-Dimensional Braided Carbon Fiber Reinforced Mullite Composites with Different Sols as Raw Materials

2015 ◽  
Vol 816 ◽  
pp. 27-32 ◽  
Author(s):  
Song Lin Liang ◽  
Qing Song Ma ◽  
Hai Tao Liu
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Carbon Fiber ◽  
Raw Materials ◽  
Three Dimensional ◽  
Solid Content ◽  
Fiber Reinforced ◽  
Ceramic Yield ◽  
Carbon Fiber Reinforced ◽  
Microstructures And Mechanical Properties

In order to efficiently fabricate dense three-dimensional carbon fiber reinforced mullite matrix composites (3D C/mullite), two kinds of Al2O3-SiO2sols with high solid content were used as raw materials. The ceramic yield and mullitization behavior of the sols and the densification process were investigated. It is indicated that the two sols have proper solid content and ceramic yield and can be completely transformed into mullite at 1573K, which make them be able to prepare composites. 3D C/mullite composites with a porosity of ∼25% were prepared by repeating less than 20 cycles of infiltration-drying-heating of sols, and the microstructures and mechanical properties were examined. The results suggest that the sol with smaller particle size derived composites exhibit well-sintered dense matrix and physically stronger interfacial bonding, which are beneficial to improve load-bearing and load-transferring capacity of matrix. As a result, this composites show much higher mechanical properties. The flexural strength and modulus are 2.4 times and 1.3 times as those of the sol with larger particle size derived composites, respectively.

A Study of Alumina Spray Dried Granules on Packing Density and Sintering Shrinkage of Simple and Complex Shape

2014 ◽  
Vol 608 ◽  
pp. 175-180
Author(s):  
Kritkaew Somton ◽  
Kannigar Dateraksa ◽  
Ryan C. McCuiston
Keyword(s):  
Particle Size ◽  
Complex Shape ◽  
Green Density ◽  
Tap Density ◽  
Complex Shapes ◽  
Liquid Immersion ◽  
Sintering Shrinkage ◽  
The Relationship ◽  
Specific Fracture ◽  
Spray Dried

The relationship between granule property, pressed green density and shrinkage of 92% alumina spray dried granules were studied for both simple and complex shapes. Two types of granules, the in-house granule (A) and the commercial granule (B), was observed morphology using microscopy and liquid immersion techniques. Examination of the granules showed that granule A have several undesirable features; agglomeration, hollow granules and non-spherical granules where granule B showed them to be unagglomerated and spherical. The mixture A and B were conducted to study the particle size distribution (PSD) and compared with Dinger-Funks ideal PSD. The result showed that granule mixture A: B 100:0 had closest PSD curve fitted but had lowest tapping and pressed green density than 70:30 and 30:70 mixtures. This is because the agglomerated shape in granule mixture 100:0 caused air gap in between granule contact resulting in low tap density. The specific fracture strengths of the granules can affect to the densification of green ceramic during pressing. Low pressed green density affected to a high amount of shrinkage during sintering and leading to small grain growth after sintered. The simple and complex shape follows the same trend in shrinkage.

Quality of spray dried soy beverage powder as affected by drying and feed parameters

2017 ◽  
Vol 47 (4) ◽  
pp. 567-577 ◽  
Author(s):  
Saroj Kumar Giri ◽  
Shukadev Mangaraj ◽  
Lalan Kumar Sinha ◽  
Manoj Kumar Tripathi
Keyword(s):  
Particle Size ◽  
Spray Drying ◽  
Air Temperature ◽  
Feed Rate ◽  
Quality Parameters ◽  
Solid Content ◽  
Surface Model ◽  
Content Type ◽  
Drying Conditions ◽  
Spray Dried

Purpose Soy beverage is becoming more and more popular because it is touted as a healthy food containing useful phytochemicals and is free from lactose and cholesterol. The purpose of this paper is to optimize the spray drying process parameters for obtaining soy beverage powder with good reconstitution and handling properties. Design/methodology/approach Pre-concentrated soy beverage was dried in a laboratory model spray dryer, and the effects of inlet air temperature (180-220°C), feed rate (20-40 ml/min) and feed solid content (15-25 per cent) on some physical parameters and reconstitution properties (wettability and dispersibility) of spray-dried soy beverage powders were investigated. Second order polynomial response surface model was selected for the analysis of data and optimization of the process. Findings Spray drying of soy beverage at different processing conditions resulted in powders with particle size (volume mean diameter) in the range of 86 to 156 µm. Dispersibility and wetting time of the spray-dried soy beverage powders was found to be in the range of 56 to 78 per cent and 30 to 90 s respectively, under various drying conditions. Inlet air temperature was found to be the main factor affecting most of the quality parameters, followed by solid content of the feed. Temperature significantly affected the wettability, dispersibility, colour parameters, particle size and flowability of the powder at p ≤ 0.01. Lower temperature and higher feed solid content produced bigger-sized powder particles with better handling properties in terms of flowability and cohesiveness. A moderate inlet air temperature (196°C), higher feed solid content (24 per cent) and lower feed rate (27 ml/min) were found suitable for drying of soy beverage. Practical implications The study implied the possibility of producing powder from soy beverage using the spray-drying method and optimized drying conditions for obtaining soy beverage powder with good reconstitution properties. Originality/value The finding of this study demonstrated for the first time how the inlet air temperature, feed solid content and feed rate during spray-drying influenced different quality parameters of soy beverage powder. Further, an optimized drying condition has been identified.

scholarly journals Tailoring Aerogel for Thermal Spray Applications in Aero-Engines: A Screening Study

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Nadiir Bheekhun ◽  
Abd Rahim Abu Talib ◽  
Mohd Roshdi Hassan
Keyword(s):  
Particle Size ◽  
Silica Aerogel ◽  
Volume Fraction ◽  
Thermal Spraying ◽  
Solid Content ◽  
Yttria Stabilized Zirconia ◽  
Stabilized Zirconia ◽  
Median Particle Size ◽  
Median Particle ◽  
Spray Dried

Irregular silica aerogel particles had been tailored to a regular spherical shape within the proper granulometric size range for thermal spraying. Silica aerogel is an ultralow dense and highly porous nanomaterial with its thermal conductivity being the lowest than any solids. Although silica aerogels possess fascinating physical properties, their implementation is limited to aerogel-doped blankets in the aerospace industry. Due to space constraints, these heat insulative and fireproof blankets are not encouraged by aero-engine manufacturers, and hence, alternatives are being sought. Although it was thought that an aerogel-based thermally sprayed coating may be applicable, aerogel powders are extremely challenging to be injected and deposited by thermal spray guns because of their inappropriate granulometric and morphological properties. Consequently, this study intends to tailor the aerogel powders accordingly. Aerogel-based slurries with yttria-stabilized zirconia as a secondary ceramic were prepared and spray-dried according to a modified Taguchi experimental design in order to appreciate the effect of both the slurry formulation and drying conditions such as the solid content, the ratio of yttria-stabilized zirconia : aerogel added, the amount of dispersant and binder, inlet temperature, atomization pressure, and feeding rate on the aforementioned characteristics of the resulting spray-dried powder. Uniformity was found to be the most influenced one (F-ratio = 62.40) by the overall spray-drying process. Solid content had the most significant effect on median particle size (p value = 0.035) and volume fraction (p value = 0.010) but did not affect uniformity significantly (p value = 0.065). Furthermore, a strong positive and significant correlation existed (Pearson’s r = 0.930) between median particle size and volume fraction. Based on the derived relationships, an optimised condition to achieve the maximum median particle size was then predicted and verified experimentally. The optimised aerogel-based spray-dried powder had a median particle size, volume fraction, and uniformity of 28.93 ± 0.726 μm, 64.45 ± 0.535, and 0.475 ± 0.002, respectively. Finally, the morphology of the optimised powder was noticed to have been changed from irregular shapes to spherical or donut-like granules which made them within the frame of thermally sprayable. However, when the optimised spray-dried powder was weighed, the quantity was found to be 10% only from the total weight of ceramics within the slurry prior to spray-drying, which makes it uneconomically reasonable for subsequent thermal spraying.

scholarly journals Characterization of Forcespun Polycaprolactone Fibers Infused with Bio-Based Hydroxyapatite for Biomedical Applications

2020 ◽  
Vol 2 (2) ◽  
pp. 23
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Biomedical Applications ◽  
Size Reduction ◽  
Biological Assessment ◽  
Fish Scales ◽  
Particle Size Reduction ◽  
Uniform Dispersion ◽  
Bead Mill

A novel Force spinning technique was used to fabricate microfibers from polycaprolactone (PCL) infused with bio-based hydroxyapatite (HA). The aim of this study is to analyze the thermo-mechanical properties of the developed fibers in addition to cell adhesion and proliferation analysis. The HA is synthesized from sundried raw fish scales of carpa family. The fish scales are calcinated at 800°C in a box furnace and are bead milled for one hour in a nano agitator bead mill for particle size reduction. Thus obtained nanoparticles are characterized using XRD, SEM, and TEM for particle size reduction, crystallinity, and structure. The PCL solution formed by dissolving 16 wt% of PCL in chloroform is magnetically stirred for 3 hrs at 170 rpm. The HA nanoparticles were infused in this solution by 1, 2, and 3 wt% and is stirred in a think mixer under vacuum for 7 mins for uniform dispersion of nanoparticles in the solution. The solution mixture is injected into the spinneret of force spinning apparatus. The PCL/HA fibers were collected at rotational aped 7000 rpm with a spin time of 10mins. The thermo-mechanical properties of the fibers were analyzed using tensile test, DSC, and DMA analyses. The biological assessment of the fibers is done using in vitro cell studies of the scaffolds that were cut from the fibers. These scaffolds can be further used for various biomedical applications such as sutures and controlled wound healing.

Characterization of Simultaneously Gas Atomized Ti/TiC Composite Powders

2016 ◽  
Vol 704 ◽  
pp. 302-307 ◽  
Author(s):  
Tze Yang Yeh ◽  
Kuo Yuan Peng
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Powder Metallurgy ◽  
Metal Matrix ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
Composite Powders ◽  
Tap Density ◽  
Mechanical Properties Testing

Metallic composite materials are mainly manufactured by powder metallurgy (PM) or casting, with reinforced ceramic particulates dispersed in a metal matrix. The current study presents an investigation with respect to simultaneously gas-atomized spherical Ti/TiC composite powders. Various analytical methods are used to characterize the gas-atomized Ti/TiC composite powders, including XRD, laser particle size analysis, flow rate tests, apparent density and tap density tests, SEM, and alike. The spherical Ti/TiC composite powders will be further laser sintered at the next stage to utilize mechanical properties testing.

scholarly journals Síntese e caracterização do compósito zircônia/alumina para aplicação em próteses

2020 ◽  
pp. 27-37
Author(s):  
Viviane S Gomide
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Particle Size ◽  
Biomedical Applications ◽  
Human Fibroblasts ◽  
Life Quality ◽  
Mechanical Resistance ◽  
Alumina Composite ◽  
Selection Of

The need to repair or reconstruct bone tissues drives the development to biomedical applications by providing better life quality for people who need to resort to the replacement of tissues. For the selection of the material to be used, it is necessary to evaluate some fundamental factors such as: mechanical resistance and biocompatibility. Often, only one material does not have all the desired properties, requiring the formation of composites in order to guarantee the appropriate characteristics. The present work presents the mechanical properties of a ceramic zirconia/alumina composite developed for application as prostheses; cytotoxicity in human fibroblasts was tested in vitro. Compressive strength, microhardness, fracture toughness and particle size measurements were also performed.

Cellulose Nanofibrils-based Hydrogels for Biomedical Applications: Progresses and Challenges

2020 ◽  
Vol 27 (28) ◽  
pp. 4622-4646 ◽  
Author(s):  
Huayu Liu ◽  
Kun Liu ◽  
Xiao Han ◽  
Hongxiang Xie ◽  
Chuanling Si ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Metal Ion ◽  
Biomedical Applications ◽  
Biomedical Application ◽  
Cellulose Nanofibrils ◽  
Wound Dressings ◽  
Preparation Methods ◽  
Tissue Scaffold ◽  
Surface Areas ◽  
Mechanical Methods

Background: Cellulose Nanofibrils (CNFs) are natural nanomaterials with nanometer dimensions. Compared with ordinary cellulose, CNFs own good mechanical properties, large specific surface areas, high Young's modulus, strong hydrophilicity and other distinguishing characteristics, which make them widely used in many fields. This review aims to introduce the preparation of CNFs-based hydrogels and their recent biomedical application advances. Methods: By searching the recent literatures, we have summarized the preparation methods of CNFs, including mechanical methods and chemical mechanical methods, and also introduced the fabrication methods of CNFs-based hydrogels, including CNFs cross-linked with metal ion and with polymers. In addition, we have summarized the biomedical applications of CNFs-based hydrogels, including scaffold materials and wound dressings. Results: CNFs-based hydrogels are new types of materials that are non-toxic and display a certain mechanical strength. In the tissue scaffold application, they can provide a micro-environment for the damaged tissue to repair and regenerate it. In wound dressing applications, it can fit the wound surface and protect the wound from the external environment, thereby effectively promoting the healing of skin tissue. Conclusion: By summarizing the preparation and application of CNFs-based hydrogels, we have analyzed and forecasted their development trends. At present, the research of CNFs-based hydrogels is still in the laboratory stage. It needs further exploration to be applied in practice. The development of medical hydrogels with high mechanical properties and biocompatibility still poses significant challenges.

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