Artificial Ageing, Chemical Resistance, and Biodegradation of Biocomposites from Poly(Butylene Succinate) and Wheat Bran

The results of comprehensive studies on accelerated (artificial) ageing and biodegradation of polymer biocomposites on PBS matrix filled with raw wheat bran (WB) are presented in this paper. These polymer biocomposites are intended for the manufacture of goods, in particular disposable packaging and disposable utensils, which decompose naturally under the influence of biological agents. The effects of wheat bran content within the range of 10–50 wt.% and extruder screw speed of 50–200 min−1 during the production of biocomposite pellets on the resistance of the products to physical, chemical, and biological factors were evaluated. The research included the determination of the effect of artificial ageing on the changes of structural and thermal properties by infrared spectra (FTIR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). They showed structural changes—disruption of chains within the ester bond, which occurred in the composition with 50% bran content as early as after 250 h of accelerated ageing. An increase in the degree of crystallinity with ageing was also found to be as high as 48% in the composition with 10% bran content. The temperature taken at the beginning of weight loss of the compositions studied was also lowered, even by 30 °C at the highest bran content. The changes of mechanical properties of biocomposite samples were also investigated. These include: hardness, surface roughness, transverse shrinkage, weight loss, and optical properties: colour and gloss. The ageing hardness of the biocomposite increased by up to 12%, and the surface roughness (Ra) increased by as much as 2.4 µm at the highest bran content. It was also found that ageing causes significant colour changes of the biocomposition (ΔE = 7.8 already at 10% bran content), and that the ageing-induced weight loss of the biocomposition of 0.31–0.59% is lower than that of the samples produced from PBS alone (1.06%). On the other hand, the transverse shrinkage of moldings as a result of ageing turned out to be relatively small, at 0.05%–0.35%. The chemical resistance of biocomposites to NaOH and HCl as well as absorption of polar and non-polar liquids (oil and water) were also determined. Biodegradation studies were carried out under controlled conditions in compost and weight loss of the tested compositions was determined. The weight of samples made from PBS alone after 70 days of composting decreased only by 4.5%, while the biocomposition with 10% bran content decreased by 15.1%, and with 50% bran, by as much as 68.3%. The measurements carried out showed a significant influence of the content of the applied lignocellulosic fillers (LCF) in the form of raw wheat bran (WB) on the examined properties of the biocompositions and the course of their artificial ageing and biodegradation. Within the range under study, the screw speed of the extruder during the production of biocomposite pellets did not show any significant influence on most of the studied properties of the injection mouldings produced from it.

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Erosion characteristics on surface texture of additively manufactured AlSi10Mg alloy in SiO2 quartz added slurry environment

Rapid Prototyping Journal ◽

10.1108/rpj-10-2021-0283 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Recep Demirsöz ◽

Mehmet Erdl Korkmaz ◽

Munish Kumar Gupta ◽

Alberto Garcia Collado ◽

Grzegorz M. Krolczyk

Keyword(s):

Surface Roughness ◽

Weight Loss ◽

Wear Resistance ◽

Erosive Wear ◽

Oxide Ceramics ◽

Slurry Erosion ◽

Content Type ◽

Test Setup ◽

Quartz Sands ◽

Erosion Test

Purpose The main purpose of this work is to explore the erosion wear characteristics of additively manufactured aluminium alloy. Additive manufacturing (AM), also known as three-dimensional (3D) manufacturing, is the process of manufacturing a part designed in a computer environment using different types of materials such as plastic, ceramic, metal or composite. Similar to other materials, aluminum alloys are also exposed to various wear types during operation. Production efficiency needs to be aware of its reactions to wearing mechanisms. Design/methodology/approach In this study, quartz sands (SiO2) assisted with oxide ceramics were used in the slurry erosion test setup and its abrasiveness on the AlSi10Mg aluminum alloy material produced by the 3D printer as selective laser melting (SLM) technology was investigated. Quartz was sieved with an average particle size of 302.5 µm, and a slurry environment containing 5, 10 and 15% quartz by weight was prepared. The experiments were carried out at the velocity of 1.88 (250 rpm), 3.76 (500 rpm) and 5.64 m/s (750 rpm) and the impact angles 15, 45 and 75°. Findings With these experimental studies, it has been determined that the abrasiveness of quartz sand prepared in certain particle sizes is directly related to the particle concentration and particle speed, and that the wear increases with the increase of the concentration and rotational speed. Also, the variation of weight loss and surface roughness of the alloy was investigated after different wear conditions. Surface roughness values at 750 rpm speed, 10% concentration and 75° impingement angle are 0.32 and 0.38 µm for 0 and 90° samples, respectively, with a difference of approximately 18%. Moreover, concerning a sample produced at 0°, the weight loss at 250 rpm at 10% concentration and 45° particle impact angle is 32.8 mg, while the weight loss at 500 rpm 44.4 mg, and weight loss at 750 rpm is 104 mg. Besides, the morphological structures of eroded surfaces were examined using the scanning electron microscope to understand the wear mechanisms. Originality/value The researchers verified that this specific coating condition increases the slurry wear resistance of the mentioned steel. There are many studies about slurry wear tests; however, there is no study in the literature about the quartz sand (SiO2) assisted slurry-erosive wear of AlSi10Mg alloy produced with AM by using SLM technology. This study is needed to fill this gap in the literature and to examine the erosive wear capability of this current material in different environments. The novelty of the study is the use of SiO2 quartz sands assisted by oxide ceramics in different concentrations for the slurry erosion test setup and the investigations on erosive wear resistance of AlSi10Mg alloy manufactured by AM.

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A Note on the Surface Deterioration of Scrimber Composites Exposed to Artificial Ageing

Coatings ◽

10.3390/coatings9120846 ◽

2019 ◽

Vol 9 (12) ◽

pp. 846

Author(s):

Minzhen Bao ◽

Fei Rao ◽

Sheng He ◽

Yongjie Bao ◽

Zaixing Wu ◽

...

Keyword(s):

Light Exposure ◽

Surface Characteristics ◽

Resin Content ◽

Color Variation ◽

Accelerated Ageing ◽

Artificial Ageing ◽

Surface Color ◽

Surface Contact Angle ◽

Xenon Light ◽

Surface Gloss

The effect of ultraviolet radiation on the surface deterioration of scrimber composites with different densities and levels of resin content was investigated for this paper. The surface color, gloss, roughness, and wettability of the samples were investigated to determine the extent of surface changes due to accelerated ageing. The results indicated that all scrimber composites exhibited variation in the color of their surfaces during artificial xenon light exposure. After artificial accelerated ageing, the surface contact angle and roughness were found to increase, whereas the surface gloss and surface free energy decreased. Furthermore, it was observed that the density and resin content of the scrimber composites contributed to reductions in their color variation, wettability, and roughness during weathering, which suggested that the density and resin content played important roles in determining their surface photodegradation properties. Artificial ageing resulted in the degradation of lignin and hemicellulose, thus causing severe surface characteristics.

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Single Wafer Amorphous Silicon Process Evaluation

MRS Proceedings ◽

10.1557/proc-467-633 ◽

1997 ◽

Vol 467 ◽

Author(s):

David O'Meara ◽

Chow Ling Chang ◽

Roc Blumenthal ◽

Rama I. Hegde ◽

Lata Prabhu ◽

...

Keyword(s):

Surface Roughness ◽

Surface Morphology ◽

Amorphous Silicon ◽

Deposition Rate ◽

Cross Sections ◽

Growth Conditions ◽

Degree Of Crystallinity ◽

Deposition Parameters ◽

Before And After ◽

Production Requirement

ABSTRACTSingle wafer amorphous silicon deposition was characterized through process modeling and film characterization for application in semiconductor production. DOE methodology was used to determine the main deposition parameters, and the responses were limited to device production requirement properties of surface roughness, deposition rate and degree of crystallinity of the as-deposited film. The data trends and models show that deposition temperature and silane flow are the main factors. Increasing either or both factor increases the deposition rate and the surface roughness. The surface morphology, evaluated by AFM, SEM and TEM, was found to be rougher at extreme growth conditions than the poly crystalline film formed after anneal. The as-deposited surface morphology was not a result of pre-anneal crystal formations as determined by TEM cross sections of samples before and after anneal. Lack of crystalinity is important for impurity diffusion considerations. Device application of the single wafer a-Si process will be a compromise between growth rate (and associated throughput) and surface roughness that can be tolerated.

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Surface Properties and Cell Response of Bioactive Thermally Grown TiO2 Nanofibers

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.575.219 ◽

2014 ◽

Vol 575 ◽

pp. 219-222

Author(s):

A.W. Tan ◽

Belinda Pingguan-Murphy ◽

Roslina Ahmad ◽

Sheikh Akbar

Keyword(s):

Surface Roughness ◽

Articular Chondrocytes ◽

Substrate Surface ◽

Control Sample ◽

Degree Of Crystallinity ◽

Crystallographic Structure ◽

Cartilage Growth ◽

Bovine Articular Chondrocytes

Titania nanofiber (TiO2 NFs) arrays were fabricated in situ on a Ti-6Al-4V substrate by an oxidation process. Their surface morphology, crystallographic structure, surface roughness and wettability were characterized, as well as their in vitro interaction with bovine articular chondrocytes at different time points. Results showed that TiO2 NFs possessed greater surface roughness, hydrophilicity and degree of crystallinity. The in vitro cell studies revealed that TiO2 NFs substrate triggers enhanced cell adhesion, proliferation and extracellular matrix (ECM) formation compared to the untreated control sample. These results showed that chondrocytes have an affinity to the nanofibrous substrate surface and thus we suggest that such surfaces are suited to be used as an implant designed for cartilage growth.

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Artificial Ageing of Photocatalytic Nanocomposites for the Protection of Natural Stones

Coatings ◽

10.3390/coatings10080729 ◽

2020 ◽

Vol 10 (8) ◽

pp. 729 ◽

Cited By ~ 1

Author(s):

Marco Roveri ◽

Sara Goidanich ◽

Lucia Toniolo

Keyword(s):

Outdoor Exposure ◽

Research Field ◽

Chemical Degradation ◽

Titania Nanoparticles ◽

Solar Irradiation ◽

Accelerated Ageing ◽

Accurate Information ◽

Artificial Ageing ◽

Stone Conservation ◽

Natural Stones

During the last ten years, photocatalytic nanocomposites combining titania nanoparticles with silicon-based matrices have received increasing attention in the stone conservation research field, because they offer an effective multifunctional approach to the issue of stone protection. However, much work still has to be done in studying the behaviour of these nanocomposites in real environmental conditions and understanding to what extent they are able to retain their effectiveness and compatibility once applied on outdoor surfaces. The latter is a key information that should lie at the basis of any successful conservation and maintenance campaign. The present study provides insight into this relevant topic trough laboratory testing by assessing the artificial ageing of two silane-based photocatalytic nanocomposites, previously selected through an accurate testing on different natural stones. Three accelerated ageing procedures, based on artificial solar irradiation, heating and rain wash-out, allowed simulating about two years of outdoor exposure to some of the weathering factors to which stones are normally subjected. The results provided quite accurate information about the long-term behaviour of the products and on the role that the stone properties play therein. It was shown that, when the products are able to penetrate deeply enough inside the stone pores, they retain much of their hydrophobising and photocatalytic properties and maintain a good compatibility with the stone substrates, even after partial chemical degradation of the alkyl-silica matrices has occurred on the very stone surface.

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Corrosion of Glazes Coated with Functional Films in Detergent Solutions

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.45.156 ◽

2006 ◽

Vol 45 ◽

pp. 156-161 ◽

Cited By ~ 7

Author(s):

Minna Piispanen ◽

Linda Fröberg ◽

Thomas Kronberg ◽

Sami Areva ◽

Leena Hupa

Keyword(s):

Surface Roughness ◽

Everyday Life ◽

Surface Topography ◽

Chemical Resistance ◽

Sol Gel ◽

Optical Microscope ◽

Alkaline Environments ◽

Zirconia Films ◽

Excellent Chemical ◽

Detergent Solutions

The goal of this work was to establish the compatibility of mat glazes with functional films known to render the surfaces with self-cleaning or easy-to-clean properties. Glazes with wollastonite, pseudowollastonite, diopside and zircon as the main crystalline phases in the surfaces were coated with fluoropolymer as well as ceramic, sol-gel derived titania and zirconia films. The glazes were soaked in typical detergent solutions used in everyday life up to four days. The surface roughness was measured with confocal optical microscope and the surface was imaged and analyzed with SEM/EDXA. When applied on wollastonite and pseudowollastonite containing glazes the functional films readily reacted in water solutions by pitting of the surface in the vicinity of the crystals. The ceramic titania and zirconia films showed better chemical resistance on wollastonite –free glazes, while the fluoropolymer film corroded in the most alkaline environments. The results indicate that functional films could be used also on rough surfaces without markedly affecting the surface topography. However, the films should be applied only on glazes with an excellent chemical resistance.

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Effect of Cockele Shells on Mortars Performance in Extreme Conditions

Civil and Environmental Engineering Reports ◽

10.2478/ceer-2019-0017 ◽

2019 ◽

Vol 29 (2) ◽

pp. 60-73

Author(s):

Assia Abdelouahed ◽

Houria Hebhoub ◽

Leila Kherraf ◽

Mouloud Belachia

Keyword(s):

Weight Loss ◽

Significant Influence ◽

Cementitious Materials ◽

Supplementary Cementitious Materials ◽

Extreme Conditions ◽

Depth Of Penetration ◽

Fresh State ◽

Lower Depth ◽

Kinetics Of ◽

Cockle Shell

Abstract This paper studies the use of cockle shell as supplementary cementitious materials SCMs as substitute for cement. The cockle shells generally have a high CaO content which can alter the behavior and the properties of mortars and concrete. Cockle shell is used with weight ratios of 5, 10, 15 and 20% to formulate a mortar with cockle shell and a control mortar CM with 0% of cockle shell. The properties in the fresh state, the mechanical strength and the weight loss test as well as the depth of penetration of each mixture were carried out through the conducted experiments. Consistency and density of fresh mortars were determined, the results obtained showed that cockle shell have a significant influence on the properties of mortars in the fresh state. The different results of hardened mortars show that the introduction of cockle shell tends to accelerate the development kinetics of strength at the young age but its ratio cannot be above of 5%. Mortar with 10% presented the lower depth penetration, the loss weight increased proportionally with the increasing of cockle shell amount.

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Mechanical Wear and Surface Roughness of Glass and Hybrid Ceramics

Journal of Oral & Dental Health ◽

10.33140/jodh.03.02.16 ◽

2019 ◽

Vol 3 (2) ◽

Keyword(s):

Surface Roughness ◽

Weight Loss ◽

Wear Resistance ◽

Glass Ceramic ◽

High Surface ◽

Lithium Disilicate ◽

Mechanical Wear ◽

Roughness Change ◽

Before And After ◽

Ceramic Blocks

Aim: The purpose of this invitro study was to evaluate wear resistance and surface roughness of two hybrid ceramics in comparison to lithium disilicate glass ceramic before and after mechanical abrasion. Materials and Methods: Thirty samples were divided according to material of construction into three groups, group (1): Lithium disilicate glass ceramic (IPS e.max, n=10), group (2): Resin nanoceramic (Lava Ultimate, n=10), group (3): Polymer infiltrated ceramic (Vita Enamic, n=10). All samples were fabricated out of CAD CAM ceramic blocks, weighed and evaluated for surface roughness before and after mechanical wear. Results: Resin nanoceramic (Lava ultimate), showed significantly low weight loss and surface roughness change after mechanical wear than IPS e.max. The polymer infiltrated ceramic (Vita Enamic) showed significantly high surface roughness than Resin nanoceramic (Lava ultimate), while IPS e.max showed the highest weight loss and surface roughness change. Conclusion: Resin nanoceramics revealed highest mechanical wear resistance contributed by terms of weight loss and surface roughness change, while Lithium disilicate glass ceramic showed the least wear resistance.

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Archaeological chert artifacts from Atapuerca sites (Burgos, Spain): Characterization, causes of decay and selection of compatible consolidating products

Conservar Património ◽

10.14568/cp2019037 ◽

2020 ◽

Author(s):

Ainara Zornoza-Indart ◽

Paula Lopez-Arce ◽

Lucía López-Polín

Keyword(s):

Surface Roughness ◽

Surface Morphology ◽

Acrylic Resin ◽

Degree Of Crystallinity ◽

Mountain Range ◽

Optical Surface ◽

Conservation Treatment ◽

Peeling Test ◽

Non Destructive ◽

Selection Of

Chert tools from Galería and Gran Dolina Caves, located in the Sierra de Atapuerca site complex (Burgos, Spain), were characterized (macro-visual inspection, mineralogical phases, degree of crystallinity, soluble salts, surface morphology and optical surface roughness) and compared to chert samples collected from the surrounding Atapuerca mountain range. The chert tools were studied to determine their causes of decay and for selecting the most compatible consolidation treatments. It was found that samples solely containing quartz were not significantly altered and required little conservation treatment compared to those that contained quartz and moganite, which were more weathered and powdery, requiring consolidation. The efficacy of the consolidating products traditionally used by conservators (acrylic resin and ethyl silicate) to preserve these chert remains, together with novel nanoparticle-based products (SiO2 and a mixture of SiO2 and Ca(OH)2 nanoparticles) were assessed in this study. Changes produced by these consolidating products in the physical (surface morphology and cohesion) and aesthetic properties of the chert tools were evaluated using non-destructive techniques (peeling test, spectrophotometry and optical surface roughness), followed by destructive techniques, such as SEM and XRD.

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Diamond Etching Beyond 10 μm with Near-Zero Micromasking

Scientific Reports ◽

10.1038/s41598-019-51970-8 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 4

Author(s):

Marie-Laure Hicks ◽

Alexander C. Pakpour-Tabrizi ◽

Richard B. Jackman

Keyword(s):

Surface Roughness ◽

Etch Rate ◽

Chemical Resistance ◽

High Quality ◽

High Performing ◽

Etched Surface

Abstract To exploit the exceptional properties of diamond, new high quality fabrication techniques are needed to produce high performing devices. Etching and patterning diamond to depths beyond one micron has proven challenging due to the hardness and chemical resistance of diamond. A new cyclic Ar/O2 - Ar/Cl2 ICP RIE process has been developed to address micromasking issues from the aluminium mask by optimising the proportion of O2 in the plasma and introducing a preferential “cleaning” step. High quality smooth features up to, but not limited to, 10.6 μm were produced with an average etched surface roughness of 0.47 nm at a diamond etch rate of 45 nm/min and 16.9:1 selectivity.

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