scholarly journals A Superhydrophobic, Antibacterial, and Durable Surface of Poplar Wood

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1885
Author(s):  
Xinyu Wu ◽  
Feng Yang ◽  
Jian Gan ◽  
Zhangqian Kong ◽  
Yan Wu
Keyword(s):  
Stearic Acid ◽  
Antibacterial Properties ◽  
Alkali Resistance ◽  
Poplar Wood ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Acid And Alkali Resistance ◽  
The Stability

The silver particles were grown in situ on the surface of wood by the silver mirror method and modified with stearic acid to acquire a surface with superhydrophobic and antibacterial properties. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray energy spectroscopy (XPS) were used to analyze the reaction mechanism of the modification process. Scanning electron microscopy (SEM) and contact angle tests were used to characterize the wettability and surface morphology. A coating with a micro rough structure was successfully constructed by the modification of stearic acid, which imparted superhydrophobicity and antibacterial activity to poplar wood. The stability tests were performed to discuss the stability of its hydrophobic performance. The results showed that it has good mechanical properties, acid and alkali resistance, and UV stability. The durability tests demonstrated that the coating has the function of water resistance and fouling resistance and can maintain the stability of its hydrophobic properties under different temperatures of heat treatment.

scholarly journals High temperature structural study of decagonal Al-Cu-Rh quasicrystal.

2014 ◽  
Vol 70 (a1) ◽  
pp. C94-C94
Author(s):  
Pawel Kuczera ◽  
Walter Steurer
Keyword(s):  
Structural Changes ◽  
Configurational Entropy ◽  
Lattice Vibrations ◽  
X Ray Diffraction ◽  
Stabilization Mechanism ◽  
X Ray ◽  
Comparative Structure ◽  
The Stability

The structure of d(ecagonal)-Al-Cu-Rh has been studied as a function of temperature by in-situ single-crystal X-ray diffraction in order to contribute to the discussion on energy or entropy stabilization of quasicrystals (QC) [1]. The experiments were performed at 293 K, 1223 K, 1153 K, 1083 K, and 1013 K. A common subset of 1460 unique reflections was used for the comparative structure refinements at each temperature. The results obtained for the HT structure refinements of d-Al-Cu-Rh QC seem to contradict a pure phasonic-entropy-based stabilization mechanism [2] for this QC. The trends observed for the ln func(I(T1 )/I(T2 )) vs.|k⊥ |^2 plots indicate that the best on-average quasiperiodic order exists between 1083 K and 1153 K, however, what that actually means is unclear. It could indicate towards a small phasonic contribution to entropy, but such contribution is not seen in the structure refinements. A rough estimation of the hypothetic phason instability temperature shows that it would be kinetically inaccessible and thus the phase transition to a 12 Å low T structure (at ~800 K) is most likely not phason-driven. Except for the obvious increase in the amplitude of the thermal motion, no other significant structural changes, in particular no sources of additional phason-related configurational entropy, were found. All structures are refined to very similar R-values, which proves that the quality of the refinement at each temperature is the same. This suggests, that concerning the stability factors, some QCs could be similar to other HT complex intermetallic phases. The experimental results clearly show that at least the ~4 Å structure of d-Al-Cu-Rh is a HT phase therefore entropy plays an important role in its stabilisation mechanism lowering the free energy. However, the main source of this entropy is probably not related to phason flips, but rather to lattice vibrations, occupational disorder unrelated to phason flips like split positions along the periodic axis.

scholarly journals Evidence for the stability of ultrahydrous stishovite in Earth’s lower mantle

2019 ◽  
Vol 117 (1) ◽  
pp. 184-189 ◽  
Author(s):  
Yanhao Lin ◽  
Qingyang Hu ◽  
Yue Meng ◽  
Michael Walter ◽  
Ho-Kwang Mao
Keyword(s):  
Transition Zone ◽  
Lower Mantle ◽  
Water Reservoir ◽  
Weight Percent ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mineral Components ◽  
The Stability ◽  
Stability Of Water

The distribution and transportation of water in Earth’s interior depends on the stability of water-bearing phases. The transition zone in Earth’s mantle is generally accepted as an important potential water reservoir because its main constituents, wadsleyite and ringwoodite, can incorporate weight percent levels of H2O in their structures at mantle temperatures. The extent to which water can be transported beyond the transition zone deeper into the mantle depends on the water carrying capacity of minerals stable in subducted lithosphere. Stishovite is one of the major mineral components in subducting oceanic crust, yet the capacity of stishovite to incorporate water beyond at lower mantle conditions remains speculative. In this study, we combine in situ laser heating with synchrotron X-ray diffraction to show that the unit cell volume of stishovite synthesized under hydrous conditions is ∼2.3 to 5.0% greater than that of anhydrous stishovite at pressures of ∼27 to 58 GPa and temperatures of 1,240 to 1,835 K. Our results indicate that stishovite, even at temperatures along a mantle geotherm, can potentially incorporate weight percent levels of H2O in its crystal structure and has the potential to be a key phase for transporting and storing water in the lower mantle.

Structural complexity of layered-spinel composite electrodes for Li-ion batteries

2010 ◽  
Vol 25 (8) ◽  
pp. 1601-1616 ◽  
Author(s):  
Jordi Cabana ◽  
Christopher S. Johnson ◽  
Xiao-Qing Yang ◽  
Kyung-Yoon Chung ◽  
Won-Sub Yoon ◽  
...  
Keyword(s):  
Structural Complexity ◽  
Composite Electrodes ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Li Ion ◽  
Excess Phase ◽  
X Ray Absorption

The complexity of layered-spinel yLi2MnO3·(1 – y)Li1+xMn2–xO4 (Li:Mn = 1.2:1; 0 ≤ x ≤ 0.33; y ≥ 0.45) composites synthesized at different temperatures has been investigated by a combination of x-ray diffraction (XRD), x-ray absorption spectroscopy (XAS), and nuclear magnetic resonance (NMR). While the layered component does not change substantially between samples, an evolution of the spinel component from a high to a low lithium excess phase has been traced with temperature by comparing with data for pure Li1+xMn2–xO4. The changes that occur to the structure of the spinel component and to the average oxidation state of the manganese ions within the composite structure as lithium is electrochemically removed in a battery have been monitored using these techniques, in some cases in situ. Our 6Li NMR results constitute the first direct observation of lithium removal from Li2MnO3 and the formation of LiMnO2 upon lithium reinsertion.

scholarly journals Gas-induced selective re-orientation of Au–Cu nanoparticles on TiO2 (110)

Nanoscale ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 752-761 ◽  
Author(s):  
Axel Wilson ◽  
Aude Bailly ◽  
Romain Bernard ◽  
Yves Borensztein ◽  
Alessandro Coati ◽  
...  
Keyword(s):  
Bimetallic Nanoparticles ◽  
Grazing Incidence ◽  
Low Pressure ◽  
Photoemission Spectroscopy ◽  
Cu Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures

Au–Cu bimetallic nanoparticles (NPs) grown on TiO2(110) have been followed in situ using grazing incidence X-ray diffraction and X-ray photoemission spectroscopy from their synthesis to their exposure to a CO/O2 mixture at low pressure (P < 10−5 mbar) and at different temperatures (300 K–470 K).

scholarly journals Electrophoretic Deposition of Copper(II)–Chitosan Complexes for Antibacterial Coatings

2020 ◽  
Vol 21 (7) ◽  
pp. 2637 ◽  
Author(s):  
Muhammad Asim Akhtar ◽  
Kanwal Ilyas ◽  
Ivo Dlouhý ◽  
Filip Siska ◽  
Aldo R. Boccaccini
Keyword(s):  
Electrophoretic Deposition ◽  
Mechanical Stability ◽  
Metallic Copper ◽  
Antibacterial Properties ◽  
Threshold Concentration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Antibacterial Coatings ◽  
Elemental Analyses ◽  
The Stability

Bacterial infection associated with medical implants is a major threat to healthcare. This work reports the fabrication of Copper(II)–Chitosan (Cu(II)–CS) complex coatings deposited by electrophoretic deposition (EPD) as potential antibacterial candidate to combat microorganisms to reduce implant related infections. The successful deposition of Cu(II)–CS complex coatings on stainless steel was confirmed by physicochemical characterizations. Morphological and elemental analyses by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy verified the uniform distribution of copper in the Chitosan (CS) matrix. Moreover, homogeneous coatings without precipitation of metallic copper were confirmed by X-ray diffraction (XRD) spectroscopy and SEM micrographs. Controlled swelling behavior depicted the chelation of copper with polysaccharide chains that is key to the stability of Cu(II)–CS coatings. All investigated systems exhibited stable degradation rate in phosphate buffered saline (PBS)–lysozyme solution within seven days of incubation. The coatings presented higher mechanical properties with the increase in Cu(II) concentration. The crack-free coatings showed mildly hydrophobic behavior. Antibacterial assays were performed using both Gram-positive and Gram-negative bacteria. Outstanding antibacterial properties of the coatings were confirmed. After 24 h of incubation, cell studies of coatings confirms that up to a certain threshold concentration of Cu(II) were not cytotoxic to human osteoblast-like cells. Overall, our results show that uniform and homogeneous Cu(II)–CS coatings with good antibacterial and enhanced mechanical stability could be successfully deposited by EPD. Such antibiotic-free antibacterial coatings are potential candidates for biomedical implants.

Impregnation of poplar wood (Populus euramericana) with methylolurea and sodium silicate sol and induction of in-situ gel polymerization by heating

Holzforschung ◽  
2014 ◽  
Vol 68 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Heyu Chen ◽  
Qian Lang ◽  
Zeng Bi ◽  
Xinwei Miao ◽  
Yu Li ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Cell Walls ◽  
Treated Wood ◽  
Poplar Wood ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
In Situ Gel ◽  
X Ray ◽  
Populus Euramericana

Abstract Poplar wood (Populus euramericana cv. “I-214”) has been impregnated by pulse dipping at 0.7–0.8 MPa for 30 min with a mixture of methylolurea and sodium silicate, and the sol modifier has been cured within the wood micropores by in situ gel polymerization by kiln drying, so that a Si-O-Si framework was formed. The treated wood acquired higher mechanical strength and its hygroscopicity was lowered. It was demonstrated by X-ray diffraction that sodium silicate crystallized within the interfibrillar region of the cell wall. Fourier transform infrared spectra showed that reactions occurred between the wood-OH, Si-OH, and N-CH2-OH from methylolurea to form C-O-Si and C-O-C bonds. As visible by scanning electron microscopy (SEM), the Si-O-Si framework was embedded in the pretreated wood. Moreover, SEM-energy-dispersive X-ray spectroscopy analysis revealed that the modifier formed layers from various thicknesses ranging from a thin layer on the cell walls up to big amounts filling the lumen.

Study of the Hydration Process of Synthetic Preparation of Ettringite by Direct Addition of Aluminum Sulfate and Calcium Hydroxide

2018 ◽  
Vol 276 ◽  
pp. 60-65
Author(s):  
Marcela Fridrichová ◽  
Dominik Gazdič ◽  
Jana Mokrá ◽  
Karel Dvořák
Keyword(s):  
Calcium Hydroxide ◽  
Aluminum Sulfate ◽  
Xrd Analysis ◽  
Standard Laboratory ◽  
X Ray Diffraction ◽  
X Ray ◽  
Saturated Water ◽  
Direct Addition ◽  
Different Temperatures ◽  
The Stability

The stability of ettringite as high-watery mineral is highly dependent on the ambient temperature. Under standard laboratory conditions, onset of decomposition of this phase occurs at temperature of 80°C already and the theoretical temperature of the complete decomposition of ettringite is 180°C. Ettringite decomposition can occur at significantly different temperatures under humidity conditions other than the laboratory ones. Within the work verification of the possibility of synthetic preparation of ettringite by direct addition of aluminum sulfate, Al2(SO4)3·18H2O, and calcium hydroxide, Ca (OH)2, as an alternative method to the yeelimite hydration procedure was carried out. The stability of the resulting systems was examined in two different environments, namely in a laboratory environment and the environment of saturated water vapour. The phase composition of the samples was determined by X-ray diffraction (XRD) analysis, thermal analysis and scanning electron microscopy (SEM).

Liquid Crystalline Behavior of Mixture of Two Non-Mesogenic Compounds

2010 ◽  
Vol 428-429 ◽  
pp. 292-296
Author(s):  
J. Mahadeva ◽  
Nagappa
Keyword(s):  
Liquid Crystalline ◽  
Interfacial Area ◽  
Ammonium Bromide ◽  
Polar Group ◽  
X Ray Diffraction ◽  
Optical Studies ◽  
X Ray ◽  
Molecular Length ◽  
Different Temperatures ◽  
The Stability

The lyotropic liquid crystalline behavior of N-Cetyl-N, N, N, Trimethyl Ammonium Bromide (CTAB) with ethylene glycol (EG) has been investigated. These compounds are non-mesogenic in nature and exhibits Sm A, Sm B and Sm G phases. The stability of the phases is investigated using X-ray diffraction and optical studies. The layer thickness and molecular length are calculated using Bragg’s equation. The interfacial area per polar group and average thickness of hydrocarbon layers are estimated for different concentrations of the mixtures at different temperatures.

In Situ Reflection High-Energy Electron Diffraction Study of Structure and Morphology Evolution of AlN Thin Films During Growth

1996 ◽  
Vol 449 ◽  
Author(s):  
F. Jin ◽  
G. W. Auner ◽  
R. Naik ◽  
P. Zatyko ◽  
U. Rao
Keyword(s):  
Electron Diffraction Study ◽  
High Energy ◽  
X Ray Diffraction ◽  
Continuous Growth ◽  
X Ray ◽  
Structure And Morphology ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Growth Methods

ABSTRACTAIN films were grown on Si (111) substrates using a PSMBE deposition system. Two types of growth methods were used: (i) a continuous growth at one temperature and (ii) a two stage growth where a buffer layer at low temperature is followed by deposition at higher temperature. The structure and morphology of the films grown at different temperatures are compared. The evolution of surface structure and morphology of the film during the growth were studied using in-situ RHEED, X-ray diffraction, and AFM.

High-temperature structural study of decagonal Al–Cu–Rh

2014 ◽  
Vol 70 (2) ◽  
pp. 306-314 ◽  
Author(s):  
Pawel Kuczera ◽  
Janusz Wolny ◽  
Walter Steurer
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Structural Study ◽  
Structural Disorder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Decagonal Phase ◽  
Comparative Structure ◽  
The Stability

The structure of decagonal Al–Cu–Rh has been studied as a function of temperature byin-situsingle-crystal X-ray diffraction in order to contribute to the discussion on energy or entropy stabilization of quasicrystals. The experiments were performed at 293, 1223, 1153, 1083 and 1013 K. A common subset of 1460 unique reflections was used for the comparative structure refinements at each temperature. A comparison of the high-temperature datasets suggests that the best quasiperiodic ordering should exist between 1083 and 1153 K. However, neither the refined structures nor the phasonic displacement parameter vary significantly with temperature. This indicates that the phasonic contribution to entropy does not seem to play a major role in the stability of this decagonal phase in contrast to other kinds of structural disorder, which suggests that, in this respect, this decagonal phase would be similar to other complex intermetallic high-temperature phases.

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