Bone-Like Mineral and Organically Modied Bone-Like Mineral Coatings

Keyword(s):  
TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 29-34
Author(s):  
TEEMU PUHAKKA ◽  
ISKO KAJANTO ◽  
NINA PYKÄLÄINEN

Cracking at the fold is a quality defect sometimes observed in coated paper and board. Although tensile and compressive stresses occur during folding, test methods to measure the compressive strength of a coating have not been available. Our objective was to develop a method to measure the compressive strength of a coating layer and to investigate how different mineral coatings behave under compression. We used the short-span compressive strength test (SCT) to measure the in-plane compressive strength of a free coating layer. Unsupported free coating films were prepared for the measurements. Results indicate that the SCT method was suitable for measuring the in-plane compressive strength of a coating layer. Coating color formulations containing different kaolin and calcium carbonate minerals were used to study the effect of pigment particles’ shape on the compressive and tensile strengths of coatings. Latices having two different glass transition temperatures were used. Results showed that pigment particle shape influenced the strength of a coating layer. Platy clay gave better strength than spherical or needle-shaped carbonate pigments. Compressive and tensile strength decreased as a function of the amount of calcium carbonate in the coating color, particularly with precipitated calcium carbonate. We also assessed the influence of styrene-butadiene binder on the compressive strength of the coating layer, which increased with the binder level. The compressive strength of the coating layer was about three times the tensile strength.


2020 ◽  
Vol 4 (12) ◽  
pp. 2337-2346
Author(s):  
Han Hua ◽  
Xin Yin ◽  
James A. Dyer ◽  
Richard Landis ◽  
Lisa Axe

1996 ◽  
Vol 88 (12) ◽  
pp. 62-73 ◽  
Author(s):  
Peter B. Merkle ◽  
William Knocke ◽  
Daniel Gallagher ◽  
Jodi Junta-Rosso ◽  
Todd Solberg

2016 ◽  
Vol 64 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Miroslav Fér ◽  
Martin Leue ◽  
Radka Kodešová ◽  
Horst H. Gerke ◽  
Ruth H. Ellerbrock

Abstract The organo-mineral coatings of soil aggregates, cracks, and biopores control sorption and macropore-matrix exchange during preferential flow, in particular in the clay-illuvial Bt-horizon of Luvisols. The soil organic matter (SOM) composition has been hypothesized to explain temporal changes in the hydraulic properties of aggregate surfaces. The objective of this research was to find relations between the temporal change in wettability, in terms of droplet infiltration dynamics, and the SOM composition of coated and uncoated aggregate surfaces. We used 20 to 40 mm sized soil aggregates from the Bt2 horizon of a Haplic Luvisol from loess that were (i) coated, (ii) not coated (both intact), and (iii) aggregates from which coatings were removed (cut). The SOM composition of the aggregate surfaces was characterized by infrared spectroscopy in the diffuse reflection mode (DRIFT). A potential wettability index (PWI) was calculated from the ratio of hydrophobic and hydrophilic functional groups in SOM. The water drop penetration times (WDPT) and contact angles (CA) during droplet infiltration experiments were determined on dry and moist aggregate samples of the three types. The decrease in the CA with time was described using the power function (CA(t) = at−b). For dry aggregates, the WDPT values were larger for coated as compared to uncoated regions on the aggregate surfaces, and increased with increasing PWI value (R2 = 0.75). The a parameter was significantly related to the WDPT (R2 = 0.84) and to the PWI (R2 = 0.64). The relations between the b parameter and the WDPT (R2 = 0.61) and the PWI (R2 = 0.53) were also significant. The WDPT values of wet soil aggregates were higher than those of dry aggregates due to high water contents, which limited the droplet infiltration potential. At the wet aggregate surfaces, the WDPT values increased with the PWI of the SOM (R2 = 0.64). In contrast to dry samples, no significant relationships were found between parameters a or b of CA(t) and WDPT or PWI for wet aggregate surfaces. The results suggest that the effect of the SOM composition of coatings on surface wettability decreases with increasing soil moisture. In addition to the dominant impact of SOM, the wettability of aggregate surfaces could be affected by different mineralogical compositions of clay in coatings and interiors of aggregates. Particularly, wettability of coatings could be decreased by illite which was the dominant clay type in coatings. However, the influence of different clay mineral fractions on surface wettability was not due to small number of measurements (2 and 1 samples from coatings and interiors, respectively) quantified.


Author(s):  
Matthias Rolf Tietze ◽  
Frank Schladitz ◽  
Manfred Curbach ◽  
Alexander Kahnt ◽  
Robert Zobel

<p>The world of construction becomes smarter. New building processes, such as building information modeling (BIM), automated manufacturing (Industry 4.0) and sustainable building are an integral part of today’s industry. Also, new material combinations, like carbon reinforced concrete, capture more and more construction applications. The number of practical examples of carbon reinforced concrete has increased. However, this is only the beginning, as the development goals have not been reached yet. After the first approved systems, further questions arise, including high-temperature-resistant reinforcement, economic production processes and the vision of an integral planned, automatically produced, and sustainable smart building. In this vision, the embedded carbon reinforcement is part of the infrastructure that enables smart-home applications and pushes the research ahead. For example, pre-pregs of carbon reinforced concrete are being developed, based on well-known carbon fiber reinforced plastic (CFRP) applications. The curing process can be controlled and brought to an end at the construction side, days, or even weeks after the pre-fab production has taken place. Automated robots are capable of placing the carbon yarn in the pre-fabricated formwork. So, the typical manufacturing (value) chain is becoming outdated, as the usual rebar or grid manufacturing is omitted</p><p>– these are also part of the current developments. Also, mineral coatings for the high-temperature- resistant reinforcement are also under development, and it is showing promising results. Another niche industry revolves around multifunctional pre-cast components with integrated heating and energy storage and load-bearing functions, which are already cheaper than the classic separated components. We lead the C³ carbon concrete composite R &amp; D project and have an overview of the latest forward- looking and visionary development approaches in carbon reinforced concrete.</p>


Biomaterials ◽  
2012 ◽  
Vol 33 (2) ◽  
pp. 713-721 ◽  
Author(s):  
Darilis Suárez-González ◽  
Kara Barnhart ◽  
Francesco Migneco ◽  
Colleen Flanagan ◽  
Scott J. Hollister ◽  
...  

2019 ◽  
Vol 19 (5) ◽  
pp. 2947-2964 ◽  
Author(s):  
Yue Huang ◽  
Jasper F. Kok ◽  
Raleigh L. Martin ◽  
Nitzan Swet ◽  
Itzhak Katra ◽  
...  

Abstract. Sand dunes and other active sands generally have a low content of fine grains and, therefore, are not considered to be major dust sources in current climate models. However, recent remote sensing studies have indicated that a surprisingly large fraction of dust storms are generated from regions covered by sand dunes, leading these studies to propose that sand dunes might be globally relevant sources of dust. To help understand dust emissions from sand dunes and other active sands, we present in situ field measurements of dust emission under natural saltation from a coastal sand sheet at Oceano Dunes in California. We find that saltation drives dust emissions from this setting that are on the low end of the range in emissions produced by non-sandy soils for similar wind speed. Laboratory analyses of sand samples suggest that these emissions are produced by aeolian abrasion of feldspars and removal of clay-mineral coatings on sand grain surfaces. We further find that this emitted dust is substantially finer than dust emitted from non-sandy soils, which could enhance its downwind impacts on human health, the hydrological cycle, and climate.


Coatings ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 536 ◽  
Author(s):  
Ying-Li Wu ◽  
Federica Villa ◽  
Gianmarco Mugnai ◽  
Marina Gallinaro ◽  
Enza Elena Spinapolice ◽  
...  

The open rock shelter of Yabelo in Ethiopia hosts diverse Holocene paintings of great cultural importance. The paintings are characterized by the presence of different mineral coatings, whose features have not been studied yet. Our goal was to understand whether different rock samples from the Yabelo paintings collected in close proximity may reveal coatings with different minerology and biology. Thus, elemental analyses combined with microscopic and molecular investigations were performed on two coatings, one whitish (sample 1) and one reddish (sample 2). Although both samples were dominated by heterotrophic bacteria, the two coatings showed distinct mineralogical and microbiological characteristics. Sample 1 contained higher amounts of Ca and P than sample 2, which was likely related to the presence of organic matter. Sample 1 hosted bacterial genera that are potentially involved in biomineralization processes, metal redox cycles and metal resistance. In contrast, sample 2 showed mainly pathogenic and commensal bacteria that are characteristic of animal and human microbiota, and other microorganisms that are involved in nitrogen and metal biogeochemical cycles. Overall, our results indicated that the bacterial communities were particular to the coating mineralogy, suggesting a potential role of the biological components in the crust genesis.


2015 ◽  
Vol 2015 (7) ◽  
pp. 558-564 ◽  
Author(s):  
S. V. Kislov ◽  
V. G. Kislov ◽  
A. V. Skazochkin ◽  
G. G. Bondarenko ◽  
A. N. Tikhonov

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