Crystals

3205 KiB

Open AccessArticle

Control of Cellular Arrangement by Surface Topography Induced by Plastic Deformation

by Aira Matsugaki and Takayoshi Nakano

Crystals 2016, 6(6), 73; https://doi.org/10.3390/cryst6060073 - 22 Jun 2016

Cited by 10 | Viewed by 5033

The anisotropic microstructure of bone tissue is crucial for appropriate mechanical and biological functions of bone. We recently revealed that the construction of oriented bone matrix is established by osteoblast alignment; there is a quite unique correlation between cell alignment and cell-produced bone [...] Read more.

The anisotropic microstructure of bone tissue is crucial for appropriate mechanical and biological functions of bone. We recently revealed that the construction of oriented bone matrix is established by osteoblast alignment; there is a quite unique correlation between cell alignment and cell-produced bone matrix orientation governed by the molecular interactions between material surface and cells. Titanium and its alloys are one of the most attractive materials for biomedical applications. We previously succeeded in controlling cellular arrangement using the dislocations of a crystallographic slip system in titanium single crystals with hexagonal close-packing (hcp) crystal lattice. Here, we induced a specific surface topography by deformation twinning and dislocation motion to control cell orientation. Dislocation and deformation twinning were introduced into α-titanium polycrystals in compression, inducing a characteristic surface structure involving nanometer-scale highly concentrated twinning traces. The plastic deformation-induced surface topography strongly influenced osteoblast orientation, causing them to align preferentially along the slip and twinning traces. This surface morphology, exhibiting a characteristic grating structure, controlled the localization of focal adhesions and subsequent elongation of stress fibers in osteoblasts. These results indicate that cellular responses against dislocation and deformation twinning are useful for controlling osteoblast alignment and the resulting bone matrix anisotropy. Full article

(This article belongs to the Special Issue Crystal Dislocations)

► Show Figures

Graphical abstract

512 KiB

Open AccessArticle

Low-Temperature Coherent Thermal Conduction in Thin Phononic Crystal Membranes

by Tuomas A. Puurtinen and Ilari J. Maasilta

Crystals 2016, 6(6), 72; https://doi.org/10.3390/cryst6060072 - 22 Jun 2016

Cited by 25 | Viewed by 4832

Abstract

In recent years, the idea of controlling phonon thermal transport coherently using phononic crystals has been introduced. Here, we extend our previous numerical studies of ballistic low-temperature heat transport in two-dimensional hole-array phononic crystals, and concentrate on the effect of the lattice periodicity. [...] Read more.

In recent years, the idea of controlling phonon thermal transport coherently using phononic crystals has been introduced. Here, we extend our previous numerical studies of ballistic low-temperature heat transport in two-dimensional hole-array phononic crystals, and concentrate on the effect of the lattice periodicity. We find that thermal conductance can be either enhanced or reduced by large factors, depending on the the lattice period. Analysis shows that both the density of states and the average group velocity are strongly affected by the periodic structuring. The largest effect for the reduction seen for larger period structures comes from the strong reduction of the group velocities, but a contribution also comes from the reduction of the density of states. For the short period structures, the enhancement is due to the enhanced density of states. Full article

(This article belongs to the Special Issue Phononic Crystals)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
A schematic of a 2D hole array phononic crystal with dimensions <math display="inline"> <semantics> <mrow> <mi>d</mi> <mo>=</mo> <mn>300</mn> </mrow> </semantics> </math> nm, a = 1 μm. Full article ">Figure 2
Radiated phonon thermal power for a selection of different phononic crystals (PnC) membranes with a square lattice hole pattern of period <math display="inline"> <semantics> <mrow> <mi>a</mi> <mo>=</mo> </mrow> </semantics> </math> 62.5 nm – 8 μm, and a full membrane with the same thickness <math display="inline"> <semantics> <mrow> <mi>d</mi> <mo>=</mo> <mn>300</mn> </mrow> </semantics> </math> nm. Full article ">Figure 3
Radiated power enhancement factor for square PnC membranes with various lattice constants a. The largest ratio of enhancement vs. reduction <math display="inline"> <semantics> <mrow> <msub> <mi>p</mi> <mtext>max</mtext> </msub> <mo>/</mo> <msub> <mi>p</mi> <mtext>min</mtext> </msub> <mo>≈</mo> <mn>92</mn> </mrow> </semantics> </math> occurs at <math display="inline"> <semantics> <mrow> <mi>T</mi> <mo>=</mo> <mn>300</mn> </mrow> </semantics> </math> mK. Full article ">Figure 4
Radiated power for selected temperature points as a function of PnC lattice constant. Full article ">Figure 5
Phonon density of states of a full membrane and four PnC membranes with the same thickness and different lattice constants. The PnC curves are smoothed for visual clarity. Full article ">Figure 6
Average group velocity of a full membrane and four PnC membranes with the same thickness and different lattice constants. The PnC curves are smoothed for visual clarity. Full article ">

12231 KiB

Open AccessArticle

Hydrogen Desorption Properties of Bulk and Nanoconfined LiBH₄-NaAlH₄

by Payam Javadian, Drew A. Sheppard, Craig E. Buckley and Torben R. Jensen

Crystals 2016, 6(6), 70; https://doi.org/10.3390/cryst6060070 - 20 Jun 2016

Cited by 20 | Viewed by 5739

Abstract

Nanoconfinement of 2LiBH₄-NaAlH₄ into a mesoporous carbon aerogel scaffold with a pore size, BET surface area and total pore volume of D_max = 30 nm, S_BET = 689 m²/g and V_tot = 1.21 mL/g, respectively [...] Read more.

Nanoconfinement of 2LiBH₄-NaAlH₄ into a mesoporous carbon aerogel scaffold with a pore size, BET surface area and total pore volume of D_max = 30 nm, S_BET = 689 m²/g and V_tot = 1.21 mL/g, respectively is investigated. Nanoconfinement of 2LiBH₄-NaAlH₄ facilitates a reduction in the temperature of the hydrogen release by 132 °C, compared to that of bulk 2LiBH₄-NaAlH₄ and the onset of hydrogen release is below 100 °C. The reversible hydrogen storage capacity is also significantly improved for the nanoconfined sample, maintaining 83% of the initial hydrogen content after three cycles compared to 47% for that of the bulk sample. During nanoconfinement, LiBH₄ and NaAlH₄ reacts to form LiAlH₄ and NaBH₄ and the final dehydrogenation products, obtained at 481 °C are LiH, LiAl, AlB₂ and Al. After rehydrogenation of the nanoconfined sample at T = 400 °C and p(H₂) = 126 bar, amorphous NaBH₄ is recovered along with unreacted LiH, AlB₂ and Al and suggests that NaBH₄ is the main compound that can reversibly release and uptake hydrogen. Full article

(This article belongs to the Special Issue Boron-Based (Nano-)Materials: Fundamentals and Applications)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
In situ SR-PXD during dehydrogenation of (A) bulk 2LiBH4-NaAlH4 heated from room temperature (RT) to 487 °C, with subsequent natural cooling to RT in p(H2) = 1 bar and (B) nanoconfined 2LiBH4-NaAlH4 in carbon aerogel (CA) heated from RT to 495 °C (ΔT/Δt = 5 °C/min, λ = 0.991779 Å). Full article ">Figure 2
(A) Thermal programmed desorption mass spectroscopy (TPD-MS) profiles of the hydrogen release (H2+ ions, m/e = 2); (B) thermogravimetric analysis (TGA); and (C) differential scanning calorimetry (DSC) measurements of bulk 2LiBH4-NaAlH4 (LiNa) (red), LiNa mixed with carbon aerogel scaffold (CA) (green) and LiNa melt infiltrated into CA (blue). The data is measured in the temperature range 40 to 550 °C and TPD-MS for each data set is normalized by its maximum hydrogen release rate to allow for qualitative comparison (ΔT/Δt = 10 °C/min). Full article ">Figure 2 Cont.
(A) Thermal programmed desorption mass spectroscopy (TPD-MS) profiles of the hydrogen release (H2+ ions, m/e = 2); (B) thermogravimetric analysis (TGA); and (C) differential scanning calorimetry (DSC) measurements of bulk 2LiBH4-NaAlH4 (LiNa) (red), LiNa mixed with carbon aerogel scaffold (CA) (green) and LiNa melt infiltrated into CA (blue). The data is measured in the temperature range 40 to 550 °C and TPD-MS for each data set is normalized by its maximum hydrogen release rate to allow for qualitative comparison (ΔT/Δt = 10 °C/min). Full article ">Figure 3
Sieverts’ measurement showing four and three hydrogen release cycles for (A) bulk 2LiBH4-NaAlH4 and (B) infiltrated into CA, LiNa-CA. Hydrogen desorption was performed at a fixed temperature of 500 °C (ΔT/Δt = 5 °C) for 10 h under an initial hydrogen pressure of 1 bar. Hydrogen absorption was performed at 400 °C, p(H2) = 126 bar for 10 h. Full article ">Figure 4
Differentiated Sieverts’ data for four and three desorption cycles of (A) bulk 2LiBH4-NaAlH4 and (B) nanoconfined 2LiBH4-NaAlH4 in CA. Full article ">Figure 5
FTIR spectra of bulk LiBH4, 2LiBH4-NaAlH4 (LiNa), and nanoconfined 2LiBH4-NaAlH4 CA-LiNa after dehydrogenation at 500 °C for the third time and finally CA-LiNa rehydrogenated at p(H2) = 140 bar, T = 400 °C for 10 h after three desorption cycles. The intensity of the spectra with the carbon containing samples was scaled corresponding to their quantity of LiNa to allow for better comparison. Full article ">

1348 KiB

Open AccessArticle

Synthesis and Crystal Structures of Two Novel O, N-Containing Spiro Compounds

by Wulan Zeng and Jinhe Jiang

Crystals 2016, 6(6), 69; https://doi.org/10.3390/cryst6060069 - 15 Jun 2016

Cited by 11 | Viewed by 4730

Abstract

Two novel O, N-containing spiro compounds, C₁₆H₁₆ClNO₄ (1) and C₁₆H₁₆N₂O₆ (2), were prepared by reactions of monosubstituted benzenamine (substituent = –NO₂, –Cl) and [...] Read more.

Two novel O, N-containing spiro compounds, C₁₆H₁₆ClNO₄ (1) and C₁₆H₁₆N₂O₆ (2), were prepared by reactions of monosubstituted benzenamine (substituent = –NO₂, –Cl) and 1,5-dioxaspiro[5.5]undecane-2,4-dione in ethanol solution of trimethoxymethane. Their structures were characterized by elemental analysis, IR, UV-Vis and single-crystal X-ray diffraction. Compound 1 is triclinic with space group P-1 and cell constants: a = 5.9448(12), b = 9.782(2), c = 13.480(3) Å, α = 100.28(3)°, β = 100.66(3)°, γ = 97.83(3)°, Mr = 321.75, V = 746.3(3) Å³, Z = 2, Dc = 1.432 g/cm³, F(000) = 336, μ(MoKa) = 0.274 mm⁻¹, the final R = 0.0544 and wR = 0.1538. Compound 2 is monoclinic with space group P21/c and cell constants: a = 12.472(3), b = 11.856(2), c = 10.643(2) Å, β = 99.83(3)°, Mr = 332.31, V = 1550.7(5) Å³, Z = 4, Dc = 1.423 g/cm³, F(000) = 696, μ(MoKa) = 0.110 mm⁻¹, the final R = 0.0444 and wR = 0.1187. In 1, there exist some intra- and inter-molecular hydrogen bonds and C–H···π supramolecular interactions, while there are still π···π stacking interactions except for some intra- and intermolecular hydrogen bonds in 2. Two compounds both form a three-dimensional network structure via above intermolecular interactions. Full article

► Show Figures

Graphical abstract

2677 KiB

Open AccessArticle

Crystal Growth and Associated Properties of a Nonlinear Optical Crystal—Ba₂Zn(BO₃)₂

by Weiguo Zhang, Hongwei Yu, Hongping Wu and P. Shiv Halasyamani

Crystals 2016, 6(6), 68; https://doi.org/10.3390/cryst6060068 - 15 Jun 2016

Cited by 19 | Viewed by 5403

Abstract

Crystals of Ba₂Zn(BO₃)₂ were grown by the top-seeded solution growth (TSSG) method. The optimum flux system for growing Ba₂Zn(BO₃)₂ crystals was 2BaF₂:2.5B₂O₃. The transmission spectra of a [...] Read more.

Crystals of Ba₂Zn(BO₃)₂ were grown by the top-seeded solution growth (TSSG) method. The optimum flux system for growing Ba₂Zn(BO₃)₂ crystals was 2BaF₂:2.5B₂O₃. The transmission spectra of a (100)-orientated crystal indicated an absorption edge of 230 nm. Powder second-harmonic generation measurement revealed that Ba₂Zn(BO₃)₂ can achieve type-I phase matching behavior at the fundamental wavelengths of 1064 and 532 nm respectively. The second-harmonic generating efficiency is around 0.85 and 0.58 times that of β-BaB₂O₄ when radiated with 1064 and 532 nm lasers. Full article

(This article belongs to the Special Issue Nonlinear Optical Crystals)

► Show Figures

Graphical abstract

5462 KiB

Open AccessArticle

Add-Drop Filter Based on Wavelength-Dependent Light Interlink between Lithium-Niobate Microwaveguide Chip and Microfiber Knot Ring

by Suxu Zhou, Yuan Wang, Donghui He, Yang Hu, Jianhui Yu, Zhe Chen, Heyuan Guan, Jun Zhang, Yunhan Luo, Jieyuan Tang and Huihui Lu

Crystals 2016, 6(6), 67; https://doi.org/10.3390/cryst6060067 - 9 Jun 2016

Cited by 8 | Viewed by 4793

Abstract

In this paper, we experimentally demonstrate an add-drop filter based on wavelength-dependent light coupling between a lithium-niobate (LN) microwaveguide chip and a microfiber knot ring (MKR). The MKR was fabricated from a standard single-mode fiber, and the LN microwaveguide chip works as a [...] Read more.

In this paper, we experimentally demonstrate an add-drop filter based on wavelength-dependent light coupling between a lithium-niobate (LN) microwaveguide chip and a microfiber knot ring (MKR). The MKR was fabricated from a standard single-mode fiber, and the LN microwaveguide chip works as a robust substrate to support the MKR. The guided light can be transmitted through add and drop functionality and the behaviors of the add-drop filter can be clearly observed. Furthermore, its performance dependence on the MKR diameter is also studied experimentally. The approach, using a LN microwaveguide chip as a platform to couple and integrate the MKR, may enable us to realize an optical interlink between the microstructured chip and the micro/nano fiber-optic device. Full article

(This article belongs to the Special Issue Lithium Niobate Crystals)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
Schematic diagram of the add-drop filter and its experimental setup. (a) Schematic diagram of the add-drop filter based on light coupling between a MKR with a lithium-niobate microwaveguide chip; (b) Schematic diagram of the experimental setup of the drop filter; (c) Photograph of the lithium-niobate microwaveguide chip and its enlarged view; (d) Photograph of MKR optically coupled with the lithium niobate microwaveguide with a diameter of ~1274.7 μm. Full article ">Figure 2
Experimental transmission spectra of the drop filter with different ring diameters of 1339.0 μm (a); 1274.7 μm (b); 1209.3 μm (c) and 1147.7 μm (d), respectively. Full article ">Figure 3
Experimental transmission spectra of the add filter with different ring diameters of 1339.0 μm (a); 1274.7 μm (b); 1209.3 μm (c); and 1147.7 μm (d), respectively. Full article ">Figure 4
Polarization-dependent loss measured from through port, drop port (drop filter) and input port (add filter). Full article ">Figure 5
(a) Schematic diagram of sectional view of lithium-niobate chip; (b) Optical mode profile of LN waveguide. Full article ">

3957 KiB

Open AccessArticle

Synthesis and Molecular Structures of the Lowest Melting Odd- and Even-Numbered α,β-Unsaturated Carboxylic Acids—(E)-Hept-2-Enoic Acid and (E)-Oct-2-Enoic Acid

by Marcel Sonneck, Anke Spannenberg, Sebastian Wohlrab and Tim Peppel

Crystals 2016, 6(6), 66; https://doi.org/10.3390/cryst6060066 - 3 Jun 2016

Cited by 1 | Viewed by 5200

Abstract

The molecular structures of the two lowest melting odd- and even-numbered α,β-unsaturated carboxylic acids—(E)-hept-2-enoic acid (C7) and (E)-oct-2-enoic acid (C8)—are herein reported. The title compounds were crystallized by slow evaporation of ethanolic solutions at [...] Read more.

The molecular structures of the two lowest melting odd- and even-numbered α,β-unsaturated carboxylic acids—(E)-hept-2-enoic acid (C7) and (E)-oct-2-enoic acid (C8)—are herein reported. The title compounds were crystallized by slow evaporation of ethanolic solutions at −30 °C. C7 crystallizes in the triclinic space group

P \bar{1}

with two molecules in the unit cell and C8 in the monoclinic space group C2/c with eight molecules in the unit cell. The unit cell parameters for C7 are: a = 5.3049(2) Å, b = 6.6322(3) Å, c = 11.1428(5) Å, α = 103.972(3)°, β = 97.542(3)°, γ = 90.104(3)°, and V = 376.92(3) Å³ (T = 150(2) K). The unit cell parameters for C8 are: a = 19.032(10) Å, b = 9.368(5) Å, c = 11.520(6) Å, β = 123.033(11)°, and V = 1721.80(16) Å³ (T = 200(2) K). Full article

► Show Figures

Graphical abstract

2269 KiB

Open AccessArticle

Synthesis and 3D Network Architecture of 1- and 16-Hydrated Salts of 4-Dimethylaminopyridinium Decavanadate, (DMAPH)₆[V₁₀O₂₈]·nH₂O

by Eduardo Sánchez-Lara, Aarón Pérez-Benítez, Samuel Treviño, Angel Mendoza, Francisco J. Meléndez, Enrique Sánchez-Mora, Sylvain Bernès and Enrique González-Vergara

Crystals 2016, 6(6), 65; https://doi.org/10.3390/cryst6060065 - 31 May 2016

Cited by 17 | Viewed by 7106

Abstract

Two hybrid materials based on decavanadates (DMAPH)₆[V₁₀O₂₈]·H₂O, (1) and (DMAPH)₆[V₁₀O₂₈]·16H₂O, (2) (where DMAPH = 4-dimethylaminopyridinium) were obtained by reactions under mild conditions at [...] Read more.

Two hybrid materials based on decavanadates (DMAPH)₆[V₁₀O₂₈]·H₂O, (1) and (DMAPH)₆[V₁₀O₂₈]·16H₂O, (2) (where DMAPH = 4-dimethylaminopyridinium) were obtained by reactions under mild conditions at T = 294 and 283 K, respectively. These compounds are pseudopolymorphs, which crystallize in monoclinic

P 2_{1} / n

and triclinic

P \bar{1}

space groups. The structural analysis revealed that in both compounds, six cations DMAPH⁺ interact with decavanadate anion through N-H∙∙∙O_dec hydrogen bonds; in 2, the hydrogen-bonding association of sixteen lattice water molecules leads to the formation of an unusual network stabilized by decavanadate clusters; this hydrogen-bond connectivity is described using graph set notation. Compound 2 differs basically in the water content which in turn increases the π∙∙∙π interactions coming from pyridinium rings. Elemental and thermal analysis (TGA/DSC) as well as FT-IR, FT-Raman, for 1 and 2 are consistent with both structures and are also presented. Full article

(This article belongs to the Section Biomolecular Crystals)

► Show Figures

Graphical abstract

Graphical abstract
Full article ">Figure 1
Structure of compound 1, (DMAPH)6[V10O28]·H2O, with displacement ellipsoids shown at the 50% probability level. Hydrogen bonds linking cations and anions are represented by dashed lines. The site occupation factor for the water molecule O30 is 1/2. The inset displays the arrangement of clusters in the crystal [<a href="#B27-crystals-06-00065" class="html-bibr">27</a>]. Full article ">Figure 2
The unit cell contents of compound 2, (DMAPH)6[V10O28]·16H2O. Displacement ellipsoids were drawn at the 50% probability level. Main atoms were labeled in the asymmetric unit, and the complete cell is generated by symmetry code 2 − x, 2 − y, 2 − z. The dashed lines represent H bonds between cations and anions. The inset represents a part of the crystal structure, omitting all lattice water molecules [<a href="#B27-crystals-06-00065" class="html-bibr">27</a>]. The orientation for this projection evidences the stacking of cations in the crystal. Full article ">Figure 3
A part of the crystal structure of 2, omitting cations. The supramolecular network formed by water molecules were based on hydrogen bonds (dashed lines, [<a href="#B27-crystals-06-00065" class="html-bibr">27</a>]). Blue H-bonds were used to form the <math display="inline"> <semantics> <mrow> <mi>C</mi> <mrow> <mo>[</mo> <mrow> <mi>R</mi> <mrow> <mo>(</mo> <mrow> <mn>10</mn> </mrow> <mo>)</mo> </mrow> <mi>R</mi> <mrow> <mo>(</mo> <mrow> <mn>12</mn> </mrow> <mo>)</mo> </mrow> </mrow> <mo>]</mo> </mrow> </mrow> </semantics> </math> backbone, in which <math display="inline"> <semantics> <mrow> <msubsup> <mi>R</mi> <mn>5</mn> <mn>5</mn> </msubsup> <mrow> <mo>(</mo> <mrow> <mn>10</mn> </mrow> <mo>)</mo> </mrow> </mrow> </semantics> </math> and <math display="inline"> <semantics> <mrow> <msubsup> <mi>R</mi> <mn>6</mn> <mn>4</mn> </msubsup> <mrow> <mo>(</mo> <mrow> <mn>12</mn> </mrow> <mo>)</mo> </mrow> </mrow> </semantics> </math> rings alternate. The different types of H-bonds were labeled<math display="inline"> <semantics> <mrow> <mo> </mo> <mi>a</mi> <mo>−</mo> <mi>i</mi> </mrow> </semantics> </math> and ring sequences are oriented counter-clockwise. Blue H-bonds connect this backbone to [V10O28]6− anions in the crystal. Full article ">Figure 4
FT-IR (a) and Raman spectra (b) of 4-dimethylaminopyridine and their corresponding hydrated decavanadate salts 1 and 2, (a) recorded in KBr pellets. Full article ">Figure 5
Images of crystal morphologies observed by optical stereoscopic microscope. (a) (DMAPH)6[V10O28]·H2O; (b) (DMAPH)6[V10O28]·16H2O. Full article ">

4944 KiB

Open AccessArticle

Phononic Crystal Plate with Hollow Pillars Actively Controlled by Fluid Filling

by Yabin Jin, Yan Pennec, Yongdong Pan and Bahram Djafari-Rouhani

Crystals 2016, 6(6), 64; https://doi.org/10.3390/cryst6060064 - 24 May 2016

Cited by 60 | Viewed by 7238

Abstract

We investigate theoretically the properties of phononic crystal plates with hollow pillars. Such crystals can exhibit confined whispering gallery modes around the hollow parts of the pillars whose localization can be increased by separating the pillar from the plate by a full cylinder. [...] Read more.

We investigate theoretically the properties of phononic crystal plates with hollow pillars. Such crystals can exhibit confined whispering gallery modes around the hollow parts of the pillars whose localization can be increased by separating the pillar from the plate by a full cylinder. We discuss the behaviors of these modes and their potential applications in guiding and filtering. Filling the hollow parts with a fluid gives rise to new localized modes, which depend on the physical properties and height of the fluid. Thus, these modes can be actively controlled for the purpose of multichannel multiplexing. In particular, one can obtain localized modes associated with the compressional vibrations of the fluid along its height. They can be used for the purpose of sensing the acoustic properties of the fluid or their variations with temperature. Full article

(This article belongs to the Special Issue Phononic Crystals)

► Show Figures

Graphical abstract

Journal Menu

Journal Browser

Crystals, Volume 6, Issue 6 (June 2016) – 9 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI