Articles de revues : « Intercalatton »

1

Zhao, Hongmei, Xiuyan Pang et Zhixiao Zhai. « Preparation and Antiflame Performance of Expandable Graphite Modified with Sodium Hexametaphosphate ». Journal of Polymers 2015 (27 juillet 2015) : 1–5. http://dx.doi.org/10.1155/2015/821297.

Texte intégral

Résumé :

A kind of polyphosphate modified expandable graphite (EGp) was prepared in graphite oxidation and intercalation reaction with KMnO4 as oxidant, H2SO4 as intercalator, and sodium hexametaphosphate (SHMP) as assistant intercalator. The feasible mass ratio of C : KMnO4 : H2SO4 (98%) : SHMP was determined as 1.0 : 0.3 : 4.5 : 0.6, H2SO4 was diluted to 77 wt% before intercalation reaction, and the reaction lasted for 40 min at 40°C. Expanded volume and initial expansion temperature of the prepared EGp reached 600 mL/g (at 800°C) and 151°C, respectively. X-ray diffraction spectroscopy testified the intercalation and layer structure of EGp, and Fourier transform infrared spectroscopy illuminated the intercalated functional groups. Flame retardance of the prepared EGp and the referenced EG (with only H2SO4 as intercalator) for linear low density polyethylene (LLDPE) was also investigated. Addition of 30 wt% EGp to the polymer improved the limiting oxygen index (LOI) from 17.5 to 27.3%. On the other hand, the LOI of the same amount of the referenced EG was only 24.6%. Assistant intercalation of SHMP improved the dilatability and flame retardancy.

Styles APA, Harvard, Vancouver, ISO, etc.

2

Luo, Xingyun, Guojun Liang, Yanlu Li, Fapeng Yu et Xian Zhao. « Regulating the Electronic Structure of Freestanding Graphene on SiC by Ge/Sn Intercalation : A Theoretical Study ». Molecules 27, n^o 24 (17 décembre 2022) : 9004. http://dx.doi.org/10.3390/molecules27249004.

Texte intégral

Résumé :

The intrinsic n-type of epitaxial graphene on SiC substrate limits its applications in microelectronic devices, and it is thus vital to modulate and achieve p-type and charge-neutral graphene. The main groups of metal intercalations, such as Ge and Sn, are found to be excellent candidates to achieve this goal based on the first-principle calculation results. They can modulate the conduction type of graphene via intercalation coverages and bring out interesting magnetic properties to the entire intercalation structures without inducing magnetism to graphene, which is superior to the transition metal intercalations, such as Fe and Mn. It is found that the Ge intercalation leads to ambipolar doping of graphene, and the p-type graphene can only be obtained when forming the Ge adatom between Ge layer and graphene. Charge-neutral graphene can be achieved under high Sn intercalation coverage (7/8 bilayer) owing to the significantly increased distance between graphene and deformed Sn intercalation. These findings would open up an avenue for developing novel graphene-based spintronic and electric devices on SiC substrate.

Styles APA, Harvard, Vancouver, ISO, etc.

3

Banks, Tony M., Samuel F. Clay, Stephen A. Glover et Rhiannon R. Schumacher. « Correction : Mutagenicity of N-acyloxy-N-alkoxyamides as an indicator of DNA intercalation part 1 : evidence for naphthalene as a DNA intercalator ». Organic & ; Biomolecular Chemistry 14, n^o 28 (2016) : 6871. http://dx.doi.org/10.1039/c6ob90099b.

Texte intégral

Résumé :

Correction for ‘Mutagenicity of N-acyloxy-N-alkoxyamides as an indicator of DNA intercalation part 1: evidence for naphthalene as a DNA intercalator’ by Tony M. Banks, et al., Org. Biomol. Chem., 2016, 14, 3699–3714.

Styles APA, Harvard, Vancouver, ISO, etc.

4

Mohammad, Hashem, Busra Demir, Caglanaz Akin, Binquan Luan, Joshua Hihath, Ersin Emre Oren et M. P. Anantram. « Role of intercalation in the electrical properties of nucleic acids for use in molecular electronics ». Nanoscale Horizons 6, n^o 8 (2021) : 651–60. http://dx.doi.org/10.1039/d1nh00211b.

Texte intégral

Résumé :

In this study, using rigorous calculations, we showed that the conductance of DNA can be tuned via intercalation, depending on the redox state of the intercalator, induced energy levels, and the Fermi energy, for use in nanoelectronics.

Styles APA, Harvard, Vancouver, ISO, etc.

5

Saito, Makoto, Kouhei Yamada et Ikuzo Kanazawa. « Topological Quasi-Positroniums in Graphite-Alkali Metal Intercalation Compounds ». Materials Science Forum 733 (novembre 2012) : 115–18. http://dx.doi.org/10.4028/www.scientific.net/msf.733.115.

Texte intégral

Résumé :

We have analyzed the positron annihilation Angular Correlation data in the second stage graphite-potassium intercalation C24K with the theoretical formula extended from "topological quasi-positronium model" and have proposed one of the possible origins of the anisotropic narrow component in alkali-metal graphite intercalations compounds (AGICs).

Styles APA, Harvard, Vancouver, ISO, etc.

6

Mazerski, J., et K. Muchewicz. « The intercalation of imidazoacridinones into DNA induces conformational changes in their side chain. » Acta Biochimica Polonica 47, n^o 1 (31 mars 2000) : 65–78. http://dx.doi.org/10.18388/abp.2000_4063.

Texte intégral

Résumé :

Imidazoacridinones (IAs) are a new group of highly active antitumor compounds. The intercalation of the IA molecule into DNA is the preliminary step in the mode of action of these compounds. There are no experimental data about the structure of an intercalation complex formed by imidazoacridinones. Therefore the design of new potentially better compounds of this group should employ the molecular modelling techniques. The results of molecular dynamics simulations performed for four IA analogues are presented. Each of the compounds was studied in two systems: i) in water, and ii) in the intercalation complex with dodecamer duplex d(GCGCGCGCGCGC)2. Significant differences in the conformation of the side chain in the two environments were observed for all studied IAs. These changes were induced by electrostatic as well as van der Waals interactions between the intercalator and DNA. Moreover, the results showed that the geometry of the intercalation complex depends on: i) the chemical constitution of the side chain, and ii) the substituent in position 8 of the ring system.

Styles APA, Harvard, Vancouver, ISO, etc.

7

Ullah, Hameed, et Ahmad Imtiaz. « Morphological Evaluation of Variously Intercalated Pre-baked Clay ». Polish Journal of Chemical Technology 16, n^o 2 (26 juin 2014) : 5–11. http://dx.doi.org/10.2478/pjct-2014-0022.

Texte intégral

Résumé :

Abstract The use of porous materials is enjoying tremendous popularity and attention of the advance scientific communities due to their excellent adsorptive and catalytic activities. Clays are one of the most important candidates in the porous community which shows the above mentioned activities after modifing with a different intercalating agent. The paper is focused on the infiuence of some inorganic intercalating agents (NaOH) on the morphology of the variously intercalated clay samples. The alkali metal was used as the inorganic intercalating agent. The effect of intercalation temperature, intercalation agent concentration and intercalation time on the pre-baked clay morphology were also part of the study. Scanning electron microscopy (SEM) study was performed to evaluate the morphological changes of the resultant intercalates. Different morphological properties were improved significantly in the case of the inorganically modified clay samples. Thus, such intercalations are suggested to be effective if the clays under study are to be used for different industrial process at elevated conditions.

Styles APA, Harvard, Vancouver, ISO, etc.

8

WANG, YAN, et THANH N. TRUONG. « CORRELATION BETWEEN ELECTRONIC STRUCTURES OF METAL-INTERCALATED SINGLE WALL CARBON NANOTUBES WITH THEIR FIELD EMISSION PROPERTIES ». Journal of Theoretical and Computational Chemistry 04, spec01 (janvier 2005) : 657–68. http://dx.doi.org/10.1142/s0219633605001702.

Texte intégral

Résumé :

The effects of various metal intercalations ( Li , Na and Be ) on the electronic structures and the field emission properties of single-wall carbon nanotubes (SWNT) were investigated using the periodic plane-wave DFT method. We found that intercalations of metal tend to shift the conductive characteristics of the SWNT from those of a semiconductor to those of a quasi-metallic conductor. The Fermi levels for all metal-intercalated in SWNT are moved toward the conduction band, induced by the charge transfer from the metal to the SWNT. Intercalations of Li and Na atoms increase the field emission current, whereas Be intercalation does not affect the field emission current due to the absence of high density of states around the Fermi level. The correlation between the electronic structures for the metal-intercalated nanowires with field emission properties is further discussed in light of the above results.

Styles APA, Harvard, Vancouver, ISO, etc.

9

Satange, Roshan, Chien-Ying Chuang, Stephen Neidle et Ming-Hon Hou. « Polymorphic G:G mismatches act as hotspots for inducing right-handed Z DNA by DNA intercalation ». Nucleic Acids Research 47, n^o 16 (30 juillet 2019) : 8899–912. http://dx.doi.org/10.1093/nar/gkz653.

Texte intégral

Résumé :

Abstract DNA mismatches are highly polymorphic and dynamic in nature, albeit poorly characterized structurally. We utilized the antitumour antibiotic CoII(Chro)2 (Chro = chromomycin A3) to stabilize the palindromic duplex d(TTGGCGAA) DNA with two G:G mismatches, allowing X-ray crystallography-based monitoring of mismatch polymorphism. For the first time, the unusual geometry of several G:G mismatches including syn–syn, water mediated anti–syn and syn–syn-like conformations can be simultaneously observed in the crystal structure. The G:G mismatch sites of the d(TTGGCGAA) duplex can also act as a hotspot for the formation of alternative DNA structures with a GC/GA-5′ intercalation site for binding by the GC-selective intercalator actinomycin D (ActiD). Direct intercalation of two ActiD molecules to G:G mismatch sites causes DNA rearrangements, resulting in backbone distortion to form right-handed Z-DNA structures with a single-step sharp kink. Our study provides insights on intercalators-mismatch DNA interactions and a rationale for mismatch interrogation and detection via DNA intercalation.

Styles APA, Harvard, Vancouver, ISO, etc.

10

RIAHI, SIAVASH, MOHAMMAD REZA GANJALI et PARVIZ NOROUZI. « QUANTUM MECHANICAL DESCRIPTION OF THE INTERACTIONS BETWEEN DNA AND 9,10-ANTHRAQUINONE ». Journal of Theoretical and Computational Chemistry 07, n^o 03 (juin 2008) : 317–29. http://dx.doi.org/10.1142/s0219633608003770.

Texte intégral

Résumé :

Molecular geometries of the 9,10-anthraquinone (AQ) and DNA bases (Adenine, Guanine, Cytosine, and Thymine) were optimized using B3LYP/6-31G** method. Properties of isolated intercalator (9,10-anthraquinone) and their stacking interactions with adenine ⋯ thymine (AT) and guanine ⋯ cytosine (GC) nucleic acid base pairs were investigated by means of DFTB method. DFTB method, an approximate version of the DFT method, was extended to cover London dispersion energy. AQ exhibits a large charge delocalization and it has no site with dominant charge. This intercalator has a large polarizability and is a good electron acceptor, while base pairs are good electron donors. B3LYP/6-31G** stabilization energies of intercalator ⋯ base pair complexes are large (-18.83 kcal/mol for AT ⋯ AQ and -15.69 kcal/mol for GC ⋯ AQ). It is concluded that, the dispersion energy predominantly contributes to the stability of intercalator ⋯ DNA base pair complexes. Any procedure which does not cover dispersion energy is thus not suitable for studying the process of intercalation. The results showed that AQ changes the structure of DNA on bond length, bond angle, torsion angle, and charges.

Styles APA, Harvard, Vancouver, ISO, etc.

11

Monaco, Regina R. « Capture of a Transition State Using Molecular Dynamics : Creation of an Intercalation Site in dsDNA with Ethidium Cation ». Journal of Nucleic Acids 2010 (2010) : 1–4. http://dx.doi.org/10.4061/2010/702317.

Texte intégral

Résumé :

The mechanism of intercalation and the ability of double stranded DNA (dsDNA) to accommodate a variety of ligands in this manner has been well studied. Proposed mechanistic steps along this pathway for the classical intercalator ethidium have been discussed in the literature. Some previous studies indicate that the creation of an intercalation site may occur spontaneously, with the energy for this interaction arising either from solvent collisions or soliton propagation along the helical axis. A subsequent 1D diffusional search by the ligand along the helical axis of the DNA will allow the ligand entry to this intercalation site from its external, electrostatically stabilized position. Other mechanistic studies show that ethidium cation participates in the creation of the site, as a ligand interacting closely with the external surface of the DNA can cause unfavorable steric interactions depending on the ligands' orientation, which are relaxed during the creation of an intercalation site. Briefly, such a site is created by the lengthening of the DNA molecule via bond rotation between the sugars and phosphates along the DNA backbone, causing an unwinding of the dsDNA itself and separation between the adjacent base pairs local to the position of the ligand, which becomes the intercalation site. Previous experimental measurements of this interaction measure the enthalpic cost of this part of the mechanism to be about −8 kcal/mol. This paper reports the observation, during a computational study, of the spontaneous opening of an intercalation site in response to the presence of a single ethidium cation molecule in an externally bound configuration. The concerted motions between this ligand and the host, a dsDNA decamer, are clear. The dsDNA decamer AGGATGCCTG was studied; the central site was the intercalation site.

Styles APA, Harvard, Vancouver, ISO, etc.

12

Ozdogru, Bertan, et Omer Ozgur Özgür Capraz. « Driving Force behind the Amorphization in the Crystalline Cathode Structures during Alkali Metal Ion Intercalation for Electrochemical Energy Storage ». ECS Meeting Abstracts MA2022-02, n^o 4 (9 octobre 2022) : 453. http://dx.doi.org/10.1149/ma2022-024453mtgabs.

Texte intégral

Résumé :

Development of cathode structures suitable for Na-ion and K-ion batteries is still one of the major challenges on the way to the design of next-generation alkali metal-ion batteries. Although Li, Na and K belong to the same alkali metal group with a single charge in their cation form, intercalation of Na+ and K+ ions in electrodes is difficult since ionic radii of Na+ (0.98 Å) and K+ (1.38 Å) are larger than that of Li+ (0.69Å). Intercalation of alkali metal ions results in volumetric expansions in the electrode structure. Even modest expansions in brittle cathodes can cause particle fracturing in a larger crystalline-size scale. Intercalation of larger ions can cause structural collapse and amorphization induced by continuous accumulation of strains and distortions. However, the lack of understanding behind the amorphization mechanisms in the crystalline electrodes upon ion intercalation materials hinders the development of electrode structures suitable for these large ions. In the first part of the talk, we will first report the utilization of in situ digital image correlation and in-operando X-ray diffraction (XRD) techniques to probe dynamic changes in the amorphous phase of iron phosphate during potassium intercalation1. A new experimental approach allows to monitor dynamic physical and structural changes in the amorphous phase of the electrodes. This method offers new insights to study mechanics of ion intercalation in the amorphous nanostructures. In the second part of the talk, we will discuss the electrochemical and mechanical response of the iron phosphate cathodes upon Li, Na and K ion intercalation. Strain evolution during Li and Na intercalation results in more linear dependence on the state of charge / discharge. However, strains generated in the electrode shows nonlinear behavior during insertion / extraction of K ions. Strain rate calculations showed that K ion intercalation results in a progressive increase in the strain rate, whereas Li and Na intercalation induce nearly constant strain rates2. Our results shows that strain rates are critical factor for the amorphization of the crystalline structure, rather than the absolute value of electrochemical strains. These observations provide a fundamental insight into the impact of alkali ions on the redox chemistry and associated chemomechanical deformations. Acknowledgement: This work was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences (Award number DE-SC0021251). References: 1) B. Ozdogru et al, Nano Letters, 21, 18, 7579–7586, 2021. 2) B. Ozdogru et. al, Electrochemical Science Advances, e2100106, 2021.

Styles APA, Harvard, Vancouver, ISO, etc.

13

Tarui, M., M. Doi, T. Ishida, M. Inoue, S. Nakaike et K. Kitamura. « DNA-binding characterization of a novel anti-tumour benzo[a]phenazine derivative NC-182 : spectroscopic and viscometric studies ». Biochemical Journal 304, n^o 1 (15 novembre 1994) : 271–79. http://dx.doi.org/10.1042/bj3040271.

Texte intégral

Résumé :

NC-182 is a novel anti-tumour compound having a benzo[a]phenazine ring. Fluorescence, absorption and c.d. spectroscopy, as well as viscometric titrations, were systematically performed to investigate the interaction mode of this drug with DNA and its effect on DNA conformation, based on comparative measurements with distamycin (DNA minor-groove binder) and daunomycin (DNA-base intercalator). NC-182 was found to be a potent intercalator of DNA, especially the B-form DNA, although no specificity was observed against the base-pair. The binding of NC-182 to B-DNA behaves biphasically, depending on the molar ratio (r) of drug to DNA: NC-182 acts to render the B-form structure rigid at relatively low r value and to promote the transformation of B- to non-B forms at high r values. It was also shown that NC-182 promotes the unwinding of Z-form DNA to B-form. Viscometric, u.v. ‘melting’ and c.d. experiments further showed that (1) the DNA duplex structure is thermally stabilized by intercalation with NC-182 and (2) the intercalation of NC-182 into a poly(dA).2poly(dT) DNA structure thermally stabilizes the triplex structure, resulting in a melting point close to that of the duplex structure; the melting curves of triplex and duplex structures coincide at r > 0.06. These observations make a significant contribution to our understanding of the biological properties of this novel benzo[a]phenazine derivative, a new anti-tumour tumour agent against multidrug-resistant and sensitive tumours.

Styles APA, Harvard, Vancouver, ISO, etc.

14

Ralph, Ray K., et Ronald Hancock. « Chromosomol DNA fragments from mouse cells exposed to an intercalating agent contain a 175-kdalton terminal polypeptide ». Canadian Journal of Biochemistry and Cell Biology 63, n^o 7 (1 juillet 1985) : 780–83. http://dx.doi.org/10.1139/o85-099.

Texte intégral

Résumé :

A 175 kdalton (kDa) polypeptide is bound covalently to the chromosomal DNA fragments from mouse cells exposed to the intercalating agent 4′-[(9-acridinyl)-amino]methansulphon-m-anisidide. Electron microscopy shows a terminal protein on the DNA fragments, whose 5′-termini are blocked. Since the relative molecular mass of topoisomerase II polypeptide chains is also about 175 kDa and topoisomerase II inhibitors prevent intercalator-induced DNA fragmentation, we propose that the polypeptide bound covalently to the 5′-terminus of the DNA fragments is a polypeptide derived from frequently integrated topoisomerase II operating to normalize torsional stress resulting from intercalation.

Styles APA, Harvard, Vancouver, ISO, etc.

15

Keller, Ray, John Shih et Carmen Domingo. « The patterning and functioning of protrusive activity during convergence and extension of the Xenopus organiser ». Development 116, Supplement (1 avril 1992) : 81–91. http://dx.doi.org/10.1242/dev.116.supplement.81.

Texte intégral

Résumé :

We discuss the cellular basis and tissue interactions regulating convergence and extension of the vertebrate body axis in early embryogenesls of Xenopus. Convergence and extension occur in the dorsal mesoderm (prospective notochord and somite) and in the posterior nervous system (prospective hindbrain and spinal cord) by sequential cell intercalations. Several layers of cells intercalate to form a thinner, longer array (radial intercalation) and then cells intercalate in the mediolateral orientation to form a longer, narrower array (mediolateral intercalation). Fluorescence microscopy of labeled mesodermal cells in explants shows that protrusive activity is rapid and randomly directed until the midgastrula stage, when it slows and is restricted to the medial and lateral ends of the cells. This bipolar protrusive activity results in elongation, alignment and mediolateral intercalation of the cells. Mediolateral intercalation behavior (MIB) is expressed in an anterior-posterior and lateral-medial progression in the mesoderm. MIB is first expressed laterally in both somitic and notochordal mesoderm. From its lateral origins in each tissue, MIB progresses medially. If convergence does not bring the lateral boundaries of the tissues closer to the medial cells in the notochordal and somitic territories, these cells do not express MIB. Expression of tissue-specific markers follows and parallels the expression of MIB. These facts argue that MIB and some aspects of tissue differentiation are induced by signals emanating from the lateral boundaries of the tissue territories and that convergence must bring medial cells and boundaries closer together for these signals to be effective. Grafts of dorsal marginal zone epithelium to the ventral sides of other embryos, to ventral explants and to UV-ventralized embryos show that it has a role in organising convergence and extension, and dorsal tissue differentiation among deep mesodermal cells. Grafts of involuting marginal zone to animal cap tissue of the early gastrula shows that convergence and extension of the hindbrain-spinal cord are induced by planar signals from the involuting marginal zone.

Styles APA, Harvard, Vancouver, ISO, etc.

16

Köhler, Olaf, Dilip V. Jarikote, Ishwar Singh, Virinder S. Parmar, Elmar Weinhold et Oliver Seitz. « Forced intercalation as a tool in gene diagnostics and in studying DNA–protein interactions ». Pure and Applied Chemistry 77, n^o 1 (1 janvier 2005) : 327–38. http://dx.doi.org/10.1351/pac200577010327.

Texte intégral

Résumé :

Aromatic and heteroaromatic groups that are forced to intercalate at specific positions in DNA are versatile probes of DNA–DNA and DNA–protein recognition. Fluorescent nucleobases are of value since they are able to report on localized alterations of DNA duplex structure. However, the fluorescence of the vast majority of base surrogates becomes quenched upon intercalation in DNA. Peptide nucleic acid (PNA)-based probes are presented in which the intercalator dye thiazole orange (TO) serves as a fluorescent base surrogate. In these probes, fluorescence increases (5–60-fold) upon hybridization. PNA-bearing TO as fluorescent base surrogate could hence prove useful in real-time polymerase chain reaction (PCR) applications and in live cell analysis. Forced intercalation of aromatic polycycles can help to explore the binding mechanism of DNA-modifying enzymes. We discuss studies of DNA-methyltransferases (MTases) which commence methylation of nucleobases in DNA by flipping the target nucleotide completely out of the helix. A method for probing the base-flipping mechanism is suggested. It draws upon the observation that large hydrophobic base surrogates in the face of the swung-out base can enhance the DNA-enzyme binding affinity possibly by disrupting target base-stacking and stabilizing the apparent abasic site.

Styles APA, Harvard, Vancouver, ISO, etc.

17

Sheikh mohd ghazali, Sheikh ahmad izaddin. « Synthesis and Characterisation of Zinc Layered Hydroxide Intercalated with 2-Methyl-4- Chlorophenoxyacetic Acid and its Controlled Release Application ». ASM Science Journal 15 (17 mai 2021) : 1–10. http://dx.doi.org/10.32802/asmscj.2021.580.

Texte intégral

Résumé :

2-methyl-4-chlorophenoxyacetic acid (MCPA) is herbicide in group of phenoxyherbicides. It has been widely used in agriculture industry to control the weeds population especially thistle and dock. The toxicity of MCPA may impact the environment and harmful for living organisms especially human and aquatic life. This research aimed to intercalate MCPA herbicide with zinc layered hydroxide (ZLH) to form a composites (ZMCPA) and its controlled release properties. In this study, ZMCPA was prepared as an advanced delivery system by ion exchange method and further by hydrothermal treatment. The intercalations of zinc oxide were done with various MCPA concentration of 0.1 M, 0.3 M, 0.5 M, 0.7 M and 0.9 M. Intercalation performances were detected using powder X- ray diffraction (PXRD) and supported by Fourier Transform infrared spectroscopy (FTIR). The study for porosity of the composite was performed by BET analyzer. Among all of these concentrations, 0.5M represented the successful intercalation due to the presence of four sharp and intense harmonic peaks at 2θ with basal spacing of 24.6 Å, 12 Å, 8 Å and 6 Å, respectively. Herbicides release study was conducted in three salt solution, sodium chloride, sodium carbonate and sodium phosphate. Sustain release of MCPA was faster in sodium phosphate solution by 85%. This controlled release study was determined by UV-Vis spectrometry.

Styles APA, Harvard, Vancouver, ISO, etc.

18

Manríquez-Ramírez, Maria Elena, Carmen Magdalena Reza-San Germán et Miriam Estrada-Flores. « Intercalation of p-toluenesulfonic acid into Mg-Al layered double hydroxide ». Superficies y Vacío 35 (30 novembre 2022) : 221101. http://dx.doi.org/10.47566/2022_syv35_1-221101.

Texte intégral

Résumé :

Layered double hydroxide represents a class of materials for selective adsorption and catalysis. In the present work, anionic p-toluenesulfonic acid (PTSA) was successfully incorporated into the interlayer domain of Mg-Al layered double hydroxide (LDH), synthesized by the co-precipitation route. Materials were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, magic angle nuclear magnetic resonance (13C MAS-NMR) spectroscopy and UV-Visible diffuse reflectance (UV-VIS/DR). All samples supported PTSA intercalation at room temperature in the basal space, the interlayer distance increased by the intercalations of the above mentioned according to the arrangement of PTSA molecules in the interlayer. The LDH-PTSA structure collapsed at 400 °C and the organic portion of those materials occurred by partial combustion, which in turn gives rise to reduced species, such as carbon and sulfide anions.

Styles APA, Harvard, Vancouver, ISO, etc.

19

Faridi, Jef, Katrine E. Nielsen, Paul C. Stein et Jens Peter Jacobsen. « Dynamic Bis-Intercalation of a Homodimeric Thiazole Orange Dye in DNA : Evidence of Intercalator Creeping ». Journal of Biomolecular Structure and Dynamics 15, n^o 2 (octobre 1997) : 321–32. http://dx.doi.org/10.1080/07391102.1997.10508195.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

20

Meng, Ya-Fang, Xiu-Yan Pang et Wei-Shu Chang. « Chemical Modification of Expandable Graphite by Boric Acid and Its Flame Retarded Application in Polyethylene ». Academic Journal of Chemistry, n^o 47 (15 juillet 2018) : 34–39. http://dx.doi.org/10.32861/ajc.47.34.39.

Texte intégral

Résumé :

The aim of this research is to get the graphite intercalation compound with high thermal stability and fire resistance. Firstly, the normal expandable graphite (EG) was prepared with potassium permanganate (KMnO4) as oxidant and sulfuric acid (H2SO4) as intercalator, respectively. Then, with (3-Aminopropyl)-trimethoxysilane (KH-550) as coupling agent, the boric acid (H3BO3) modified EG (EGB) was prepared by silane grafting method through H3BO3 bonded with EG. The analysis of X-ray powder diffractiometer and Fourier transform infrared spectroscopy testified the existence of EGB. EGB showed better thermal stability and flame retardancy for linear low density polyethylene (LLDPE) than the referenced EG. Addition of 13.0 wt% of EGB improved the limiting oxygen index (LOI) of 87.0LLDPE/13.0EGB to 24.6%, which was obviously higher than that of pure matrix of 17.5%. Whereas, the LOI of 87.0LLDPE/13EG was 22.7%. Furthermore, when EGB combined with ammonium polyphosphate (APP), the LOI and UL-94 level of 87.0LLDPE/8.7EGB/4.3APP reached 27.1% and V-0, respectively.

Styles APA, Harvard, Vancouver, ISO, etc.

21

Ferrari, Ivan Vito, Riccardo Narducci, Giuseppe Prestopino, Ferdinando Costantino, Alessio Mattoccia, Lina Di Giamberardino, Morena Nocchetti et al. « Layered Double Hydroxides as a Drug Delivery Vehicle for S-Allyl-Mercapto-Cysteine (SAMC) ». Processes 9, n^o 10 (14 octobre 2021) : 1819. http://dx.doi.org/10.3390/pr9101819.

Texte intégral

Résumé :

The intercalations of anionic molecules and drugs in layered double hydroxides (LDHs) have been intensively investigated in recent years. Due to their properties, such as versatility in chemical composition, good biocompatibility, high density and protection of loaded drugs, LDHs seem very promising nanosized systems for drug delivery. In this work, we report the intercalation of S-allyl-mercapto-cysteine (SAMC), which is a component of garlic that is well-known for its anti-tumor properties, inside ZnAl-LDH (hereafter LDH) nanostructured crystals. In order to investigate the efficacy of the intercalation and drug delivery of SAMC, the intercalated compounds were characterized using X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The increase in the interlayer distance of LDH from 8.9 Å, typical of the nitrate phase, to 13.9 Å indicated the intercalation of SAMC, which was also confirmed using FT-IR spectra. Indeed, compared to that of the pristine LDH precursor, the spectrum of LDH-SAMC was richly structured in the fingerprint region below 1300 cm−1, whose peaks corresponded to those of the functional groups in the SAMC molecular anion. The LDH-SAMC empirical formula, obtained from UV-Vis spectrophotometry and thermogravimetric analysis, was [Zn0.67Al0.33(OH)2]SAMC0.15(NO3)0.18·0.6H2O. The morphology of the sample was investigated using SEM: LDH-SAMC exhibited a more irregular size and shape of the flake-like crystals in comparison with the pristine LDH, with a reduction in the average crystallite size from 3 µm to about 2 µm. In vitro drug release studies were performed in a phosphate buffer solution at pH 7.2 and 37 °C and were analyzed using UV-Vis spectrophotometry. The SAMC release from LDH-SAMC was initially characterized by a burst effect in the first four hours, during which, 32% of the SAMC is released. Subsequently, the release percentage increased at a slower rate until 42% after 48 h; then it stabilized at 43% and remained constant for the remaining period of the investigation. The LDH-SAMC complex that was developed in this study showed the improved efficacy of the action of SAMC in reducing the invasive capacity of a human hepatoma cell line.

Styles APA, Harvard, Vancouver, ISO, etc.

22

Wang, Lin Jiang, et Xiang Li Xie. « Influence Factors for the Preparation of Kaolinite-Formamide Intercalation ». Advanced Materials Research 284-286 (juillet 2011) : 488–91. http://dx.doi.org/10.4028/www.scientific.net/amr.284-286.488.

Texte intégral

Résumé :

Kaolinite-formamide intercalation compound was prepared by solution intercalation method. The intercalation ratio(I.R.) was evaluated based on the ratio of II /(II+IK).The influence factors on intercalation efficiency such as the type and contents of solvent, the temperature of intercalation reaction and the particle size of kaolinite sample were studied. The results shown that the highest intercalation ratio was 96% under room temperature. The formamide solution with vol.9% of water, methanol or ethanol is propitious to intercalation. The kaolinite sample with particle size more than 1.5μm, high purity and good dispersion in solution, is adequate for preparation high I.R. intercalation compound.

Styles APA, Harvard, Vancouver, ISO, etc.

23

RIAHI, SIAVASH, SOLMAZ EYNOLLAHI et MOHAMMAD REZA GANJALI. « INTERACTION OF EMODIN WITH DNA BASES : A DENSITY FUNCTIONAL THEORY ». Journal of Theoretical and Computational Chemistry 09, n^o 05 (octobre 2010) : 875–88. http://dx.doi.org/10.1142/s0219633610006055.

Texte intégral

Résumé :

In this study, we present work on the physicochemical interaction between the anticancer drug molecule Emodin (ED) and DNA. Comprehending the physicochemical properties of this drug besides the mechanism by which it interacts with DNA should eventually permit the rational design of novel anticancer or antiviral drugs. The final purpose is the clarification of this novel class of drugs as potential pharmaceutical agents. The properties of the isolated intercalator ED and its stacking interactions with adenine⋯thymine (AT) and guanine⋯cytosine (GC) (nucleic acid base pairs) in face-to-face and face-to-back models were studied by means of the density functional tightbinding (DFTB) method. This method was an approximate version of the density functional theory (DFT) method and it includes London dispersion energy. The molecular modeling of the complex formed between ED and DNA indicated that this complex was capable of contributing to the formation of a constant intercalation site. The results exhibit that ED changes affect DNA structure with reference to bond lengths, bond angles, torsion angles, and charges.

Styles APA, Harvard, Vancouver, ISO, etc.

24

Kucharska, Karolina, Marta Pilz, Krzysztof Bielec, Tomasz Kalwarczyk, Patrycja Kuźma et Robert Hołyst. « Two Intercalation Mechanisms of Oxazole Yellow Dimer (YOYO-1) into DNA ». Molecules 26, n^o 12 (19 juin 2021) : 3748. http://dx.doi.org/10.3390/molecules26123748.

Texte intégral

Résumé :

The oxazole yellow dye, YOYO-1 (a symmetric homodimer), is a commonly used molecule for staining DNA. We applied the brightness analysis to study the intercalation of YOYO-1 into the DNA. We distinguished two binding modes of the dye to dsDNA: mono-intercalation and bis-intercalation. Bis-intercalation consists of two consecutive mono-intercalation steps, characterised by two distinct equilibrium constants (with the average number of base pair per binding site equals 3.5): K1=3.36±0.43×107M−1 and K2=1.90±0.61×105M−1, respectively. Mono-intercalation dominates at high concentrations of YOYO-1. Bis-intercalation occurs at low concentrations.

Styles APA, Harvard, Vancouver, ISO, etc.

25

Shioyama, H., M. B. H. M. Saman et A. Sanpanich. « Novel approaches for controlling stage structure of metal chloride–graphite intercalation compounds ». Journal of Materials Research 17, n^o 12 (décembre 2002) : 3190–92. http://dx.doi.org/10.1557/jmr.2002.0461.

Texte intégral

Résumé :

Intercalation of EuCl3 TbCl3, and AlCl3 into graphite was carried out in the presence of chlorine. The observation of products by x-ray diffraction showed that the extent of chloride intercalation could be controlled through adjustment of the pressure of chlorine; increasing pressure tended to increase the extent of intercalation. In the case of EuCl3, the extent of intercalation varied to show a stage transition. In contrast, TbCl3 intercalation gave a mixture of stage 2 or stage 4 graphite intercalation compound (GIC) and remaining graphite, where the extent of intercalation is revealed by the ratio of GIC to graphite. With respect to AlCl3 intercalation, although the preparation of stage 1, 2, and 4 GICs was successful, stage 3 and 5 GICs could not be obtained.

Styles APA, Harvard, Vancouver, ISO, etc.

26

Zheng, Shu-Qin, Ou Chen, Si-Cheng Liu, An Li, Li-Jun Li, Yong-Bing Yuan et Ceng Zhang. « Synthesis of an NaY zeolite molecular sieve from a kaolin/dimethyl sulfoxide intercalation composite ». Clay Minerals 56, n^o 1 (mars 2021) : 28–36. http://dx.doi.org/10.1180/clm.2021.10.

Texte intégral

Résumé :

AbstractNaY zeolite was synthesized from kaolin/dimethyl sulfoxide (DMSO) intercalation composites using an in situ crystallization technique. The effects of the intercalation ratios and the amounts of the kaolin/DMSO intercalation composite on the synthesis of an NaY zeolite molecular sieve were studied. The samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, differential thermal analysis, N2 adsorption–desorption and scanning electron microscopy. In the in situ synthesis system, when the kaolin/DMSO intercalation composite was added, pure NaY zeolite was formed. By increasing the amount of kaolin/DMSO intercalation composite added, the crystallinity of the samples increased, and after reaching the maximum amount of kaolin/DMSO intercalation composite added, the crystallinity decreased with further increases of the amount of kaolin/DMSO intercalation composite added. To higher intercalation ratio, the crystallinity can be greatly improved at the lower addition content. At an intercalation ratio of 84%, the added amount of kaolin/DMSO intercalation composite was 2.5% and the crystallinity of the NaY zeolite molecular sieve reached a maximum value of 45%. At intercalation ratios of 55% and 22%, the amount of kaolin/DMSO intercalation composite added was 15% and the crystallinities of the NaY zeolite molecular sieves were 44% and 47%, respectively. The NaY zeolite has good thermal stability and a particle diameter of ~0.5 μm. The Brunauer–Emmett–Teller (BET) specific surface area and pore volume of the sample were 519 m2 g–1 and 0.355 cm3 g–1, respectively.

Styles APA, Harvard, Vancouver, ISO, etc.

27

Yu, Zhenzhu, Fei Nan, Lu Su, Shaofei Zhang et Yan He. « Effect of Ammonium Bicarbonate on Intercalation and Exfoliation of Graphite Materials ». Journal of Nanomaterials 2019 (16 décembre 2019) : 1–8. http://dx.doi.org/10.1155/2019/5290496.

Texte intégral

Résumé :

Intercalation and exfoliation are key steps in the preparation of graphene by thermal exfoliation, and they determine the quality of the final product. Therefore, it is important to explore the influence of intercalation agents on the intercalation and exfoliation of graphite. In this article, ammonium bicarbonate is intercalated into graphite with different degrees of oxidation to form a graphite intercalation compound (GIC) by means of ultrasound and stirring. Then, they are exfoliated by being heated at high temperatures. After ammonium bicarbonate intercalation and heating treatment, XRD, TG, and BET show that the intercalation and exfoliation effect of graphite oxide (GO) is better than that of graphite (G) and expanded graphite (EG). The intercalation mechanism is that the ammonia molecule in ammonium bicarbonate solution contains a wedge-shaped structure and active point, which provides empty orbits for graphite electrons and forms edge intercalation through physical interaction at the same time.

Styles APA, Harvard, Vancouver, ISO, etc.

28

Wang, Lin Jiang, Da Qing Wu, Xiang Li Xie, Wen Feng Zhu et Li Gao. « Processing and Characterization of Carbothermal Reduction and Nitridation from Kaolinite-Polyacrylamide Intercalation Compound ». Key Engineering Materials 336-338 (avril 2007) : 1093–95. http://dx.doi.org/10.4028/www.scientific.net/kem.336-338.1093.

Texte intégral

Résumé :

The kaolinite-polyacrylamide intercalation compound was prepared by the displacement reaction of the kaolinite-formamide intercalation precursor with acrylamide and the polymerization under 140°C for 15h with the catalysis of dibenzoyl peroxide. Sialon was synthesized from kaolinite-polyacrylamide intercalation compound by carbothermal reduction and nitridation (CRN) processing at 1400°C. The kaolinite-carbon mixture and its CRN product were also prepared for the comparison with the CRN result of intercalation compound. XRD, FT-IR, and TEM were used to characterize the phases, structure and morphology of products. In the CRN product from the intercalation compound, β′-sialon is the main phase. And the reduction and nitridation rate from the intercalation compound was greater than that from the mixture. There was higher sialon phase’s content and lower mullite phase’s content in the CRN product from the intercalation compound than that from the mixture. The CRN processing of kaolinite intercalation compound is a novel and effective method of sialon synthesis.

Styles APA, Harvard, Vancouver, ISO, etc.

29

Mako, É., A. Kovács, E. Horváth et J. Kristóf. « Kaolinite-potassium acetate and halloysite-potasium acetate complexes prepared by mechanochemical, solution and homogenization techniques : a comparative study ». Clay Minerals 49, n^o 3 (juin 2014) : 457–71. http://dx.doi.org/10.1180/claymin.2014.049.3.08.

Texte intégral

Résumé :

AbstractKaolinite- and halloysite-potassium acetate complexes were synthesized by cogrinding with solid potassium acetate (mechanochemical intercalation). The efficiency of mechanochemical intercalation was compared to the intercalation in solution and by homogenization. The effects of ageing and grinding parameters (grinding time, sample:grinding body mass ratio (SGMR), rotational speed) and the humidity on the intercalation were studied. The degree of intercalation increased exponentially with ageing of the samples prepared by mechanochemical and homogenization techniques. For the mechanochemical and homogenization techniques the required amount of potassium acetate per gram of kaolin (∼0.4 g/g) was two orders of magnitude lower than that for the solution intercalation (78.6 g/g). The highest degree of intercalation (86%) and the lowest structural deformation were achieved by the mechanochemical method (¼ h of co-grinding with 1:2 SGMR at 300 rpm), followed by 16 h ageing at 57% relative humidity.

Styles APA, Harvard, Vancouver, ISO, etc.

30

Teranishi, Takashi, Sachi Takezawa, Kenji Toda, Hironori Ishikawa, Kenji Sato, Kazuyoshi Uematsu et Mineo Sato. « Superconductivity of Layered Perovskite Synthesized by Soft Chemistry ». Key Engineering Materials 350 (octobre 2007) : 163–66. http://dx.doi.org/10.4028/www.scientific.net/kem.350.163.

Texte intégral

Résumé :

Reduced niobates, MLixCa2Nb3O10 (M = Rb, K and Na) and KNaxCa2Nb3O10 were synthesized by intercalation reaction with n-butyllithium or sodium azide. Ruddlesden-Popper type structure of sodium intercalation compound, KNaCa2Nb3O10, differ from that of the parent compound and lithium intercalation compound, KLiCa2Nb3O10. The magnetic susceptibility measurements showed that the sodium intercalation compound became superconductor with transition temperatures below 3.5 K. New lithium intercalation compound Na0.1Li0.8Ca2.45Nb3O10, for an ion exchange compound, Na0.1Ca2.45Nb3O10, with KCa2Nb3O10 type structure show the diamagnetic signals below 5 K.

Styles APA, Harvard, Vancouver, ISO, etc.

31

Ding, Shu Li, B. H. Xu, Q. F. Liu et Y. Z. Sun. « Preparation of Nano-Kaolinite and Mechanism ». Advanced Materials Research 204-210 (février 2011) : 1217–20. http://dx.doi.org/10.4028/www.scientific.net/amr.204-210.1217.

Texte intégral

Résumé :

With potassium acetate as an intercalation agent, kaolinite-potassium acetate(KAc) intercalation complexes was prepared. Afterwards, nano-kaolinite was successfully made through exfoliated intercalation complexes using power ultrasonic. The intermediate and final products were characterized by X-ray diffraction(XRD), infrared spectroscopy(IR), laser particle size analyzer, and scanning electron microscope (SEM). The results show that intercalation of KAc into kaolinite resulted in a crystal space expansion, from a basal spacing of 7.14Ǻ to 14.20 Ǻ, and the intercalation rate was about 80%. KAc intercalation causes the weakening of interlayer stability. It was shown that the particles of nano-kaolinite is very thin lamellar in shape, whose average thickness, average particle size, are 50 nm and 450 nm respectively.

Styles APA, Harvard, Vancouver, ISO, etc.

32

Remmert, Peter, et Hans-Ulrich Hummel. « Die Einlagerung von Pyridin in ternäre Übergangsmetalldisulfide Ta1-xMoxS2 / Intercalation of Pyridine into Ternary Transition Metal Disulfides Ta1-xMoxS2 ». Zeitschrift für Naturforschung B 49, n^o 10 (1 octobre 1994) : 1387–90. http://dx.doi.org/10.1515/znb-1994-1013.

Texte intégral

Résumé :

AbstractTernary phases Ta1-xMoxS2 with 0.25 ≤ x ≤ 0.55 have been investigated regarding their intercalation potential using pyridine as guest molecule. Intercalation yields hexagonal phases Ta1-xMoxS2·(pyridine)n. The different phases have been characterized by elemental analysis as well as TGA and powder diffraction patterns, which have been indexed using the space group P3m1. For the compound Ta0.65Mo0.35S2·(pyridine)0.38 a structural model was developed, based on powder diffraction data: P3m1, a = 3.275(2), c = 12.008(7)Å and Z = 1. During intercalation the stacking sequence of the host lattice is changed from BaB/AcA/CbC to BaB(pyr)/BaB(pyr). Intercalation of pyridine into Ta1-xMoxS2 proceeds via a two-step mechanism. In the first step orthorhombic phases are formed with reduced pyridine content as compared to the final intercalation product; e.g. Ta0.55Mo0.45S2·(pyridine)0.38. The first step intercalation compounds can be obtained by interruption of the intercalation reaction after 7 days.

Styles APA, Harvard, Vancouver, ISO, etc.

33

Gao, Li, Lin Jiang Wang, Yi Ting Du et Guo Wei Zhang. « Preparation and Characterization of Kaolinite-Glucose Intercalation Compound ». Key Engineering Materials 368-372 (février 2008) : 1068–70. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.1068.

Texte intégral

Résumé :

Kaolinite-glucose intercalation compound was synthesized by the intercalation of polar organic big molecule dodecylamine and then displaced by glucose in the layer of kaolinite. XRD, FT-IR, TG and DSC were used to study the reaction process and the characters of the products. The results indicated that the basal spacing of kaolinite increased to 2.280 nm from 0.717 nm, and the hydrogen bonds were formed between dodecylamine NH and kaolinite Si-O after dodecylamine intercalation. Kaolinite-dodecylamine intercalation compound was stable below 295 °C. After displacement reaction by glucose, the basal spacing of kaolinite increased to 3.364 nm, and the intercalation rate reached 87%, the hydrogen bonds were formed between glucose C=O and kaolinite inner surface hydroxyl. Kaolinite-glucose intercalation compound was stable below 302 °C.

Styles APA, Harvard, Vancouver, ISO, etc.

34

Zhu, Xiaoyan, Jianchao Chen, Jieyu Chen, Xinrong Lei et Chunjie Yan. « Urea intercalation compound production in industrial scale for paper coating ». Chemical Industry and Chemical Engineering Quarterly 20, n^o 2 (2014) : 241–48. http://dx.doi.org/10.2298/ciceq121025007z.

Texte intégral

Résumé :

Urea intercalation compounds were produced in a new designed industrial scale. The conditions and locations of the new industrial process for the production of urea intercalation compound pigment were studied through the control of correlative parameters. Properties of the compound pigment such as particle morphology, particle size distribution and viscosity, were analyzed to evaluate its potentiality for paper coating application. Results showed that the intercalation ratio of urea intercalation compound increased from 6.3% with 2wt. % of urea addition to 56.08% with 6wt.% of urea addition. Viscosity concentration of urea intercalation compound improved from 69% of original kaolinite to the highest value, 74.23% of the compound. Particle size distribution was centralized. Properties of light weight papers coated with urea intercalation compound showed interesting results, similar to a standard grade.

Styles APA, Harvard, Vancouver, ISO, etc.

35

Tetley, Robert J., et Yanlan Mao. « The same but different : cell intercalation as a driver of tissue deformation and fluidity ». Philosophical Transactions of the Royal Society B : Biological Sciences 373, n^o 1759 (24 septembre 2018) : 20170328. http://dx.doi.org/10.1098/rstb.2017.0328.

Texte intégral

Résumé :

The ability of cells to exchange neighbours, termed intercalation, is a key feature of epithelial tissues. Intercalation is predominantly associated with tissue deformations that drive morphogenesis. More recently, however, intercalation that is not associated with large-scale tissue deformations has been described both during animal development and in mature epithelial tissues. This latter form of intercalation appears to contribute to an emerging phenomenon that we refer to as tissue fluidity—the ability of cells to exchange neighbours without changing the overall dimensions of the tissue. Here, we discuss the contribution of junctional dynamics to intercalation governing both morphogenesis and tissue fluidity. In particular, we focus on the relative roles of junctional contractility and cell–cell adhesion as the driving forces behind intercalation. These two contributors to junctional mechanics can be used to simulate cellular intercalation in mechanical computational models, to test how junctional cell behaviours might regulate tissue fluidity and contribute to the maintenance of tissue integrity and the onset of disease. This article is part of the Theo Murphy meeting issue ‘Mechanics of development’.

Styles APA, Harvard, Vancouver, ISO, etc.

36

Salamanca-Riba, L., N. C. Yeh, M. S. Dresselhaus, M. Endo et T. Enoki. « High-resolution transmission electron microscopy on KHx–GIC's ». Journal of Materials Research 1, n^o 1 (février 1986) : 177–86. http://dx.doi.org/10.1557/jmr.1986.0177.

Texte intégral

Résumé :

The in-plane and c-axis structure of KHx—GIC's and KDy—GIC's is studied using transmission electron microscopy (TEM) and x-ray diffraction as a function of intercalation temperature and time. With the TEM, two commensurate in-plane phases are found to coexist in these compounds with relative concentrations depending on intercalation conditions. When the direct intercalation method is used, the first step of intercalation is the formation of a stage n potassium-GIC and the final compound is a stage n KHx—GIC (or KDy—GIC). Highresolution (00l) lattice images show direct evidence for intermediate phases in the intercalation process. These intermediate phases are hydrogen (deuterium) deficient and are found at the boundary between pure potassium regions and regions with high hydrogen (deuterium) content. A comparison of the structure for the two methods of intercalation of KH is also presented.

Styles APA, Harvard, Vancouver, ISO, etc.

37

Wu, Limei, Shiyue Cao et Guocheng Lv. « Influence of Energy State of Montmorillonite Interlayer Cations on Organic Intercalation ». Advances in Materials Science and Engineering 2018 (13 novembre 2018) : 1–8. http://dx.doi.org/10.1155/2018/3489720.

Texte intégral

Résumé :

It is well known that the intercalation of montmorillonite (Mt) with organic cations is a fast process. During the intercalation, the interaction between the original cations and the structure layer of Mt keeps changing, and the basal spacing of Mt keeps increasing until an organic environment has been built in the interlayer. Many properties of Mt also change during the intercalation, such as hydrophobic or hydrophilic property and thermal stability. In this research, the impact of intercalation on the properties of Mt was studied by investigating the change in basal spacing and energy that coordinates the interlayer cations during the intercalation of Mt with organic cations. The interaction between interlayer cations and the layers in the Mt structure and the change in the system energy were obtained by using molecular dynamics simulation. All the experiment and calculation results provide a theoretical proof in organic intercalation mechanism.

Styles APA, Harvard, Vancouver, ISO, etc.

38

Xia, Hua, et Sheng Hui Zhang. « Synthesis, Characterization and Mechanism of Benzamide Intercalated Kaolinite by Replacement Method ». Applied Mechanics and Materials 420 (septembre 2013) : 222–29. http://dx.doi.org/10.4028/www.scientific.net/amm.420.222.

Texte intégral

Résumé :

Kaolinite/benzamide complex was prepared by displacement reaction of a kaolinite/dimethylsulphoxide (DMSO) intercalation complex with melted benzamide. The whole process was recorded by powder X-ray diffractometry (PXRD) and Fourier-transformed infrared spectroscopy (FTIR). Those PXRD and FT-IR indicated that there are two stages in the process of melted benzamide replacing intercalation. The first stage is the deintercalation of DMSO molecules in the kaolinite/dimethylsulphoxide intercalation complex. And the second stage is the melted benzamide intercalation.

Styles APA, Harvard, Vancouver, ISO, etc.

39

Casani, Sandra, Jordi Casanova et Marta Llimargas. « Unravelling the distinct contribution of cell shape changes and cell intercalation to tissue morphogenesis : the case of the Drosophila trachea ». Open Biology 10, n^o 11 (novembre 2020) : 200329. http://dx.doi.org/10.1098/rsob.200329.

Texte intégral

Résumé :

Intercalation allows cells to exchange positions in a spatially oriented manner in an array of diverse processes, spanning convergent extension in embryonic gastrulation to the formation of tubular organs. However, given the co-occurrence of cell intercalation and changes in cell shape, it is sometimes difficult to ascertain their respective contribution to morphogenesis. A well-established model to analyse intercalation, particularly in tubular organs, is the Drosophila tracheal system. There, fibroblast growth factor (FGF) signalling at the tip of the dorsal branches generates a ‘pulling’ force believed to promote cell elongation and cell intercalation, which account for the final branch extension. Here, we used a variety of experimental conditions to study the contribution of cell elongation and cell intercalation to morphogenesis and analysed their mutual requirements. We provide evidence that cell intercalation does not require cell elongation and vice versa. We also show that the two cell behaviours are controlled by independent but simultaneous mechanisms, and that cell elongation is sufficient to account for full extension of the dorsal branch, while cell intercalation has a specific role in setting the diameter of this structure. Thus, rather than viewing changes in cell shape and cell intercalation as just redundant events that add robustness to a given morphogenetic process, we find that they can also act by contributing to different features of tissue architecture.

Styles APA, Harvard, Vancouver, ISO, etc.

40

Zhu, Qian, Dai Mei Chen, Yan Liu, Xu Tao Deng, Hui Li et Zhi Jin Lu. « Preparation and Characterization of Protein-Montmorillonite Composites ». Applied Mechanics and Materials 184-185 (juin 2012) : 1120–23. http://dx.doi.org/10.4028/www.scientific.net/amm.184-185.1120.

Texte intégral

Résumé :

Protein-montmorillonite composites were prepared by direct and stepwise intercalation of lysozyme(LYZ) into gallery of montmorillonite(MMT), and characterized by X-ray Diffraction (XRD), Thermal Gravimetric Analysis(TGA) and Atomic Force Microscopy(AFM). The direct intercalation experiment showed that with the increase of LYZ/MMT weight ratio from 1:1 to 4:1, the interlayer space of MMT increased from 4.2nm to 6.3nm, and the adsorption amount of lysozyme onto MMT increased from 1.05mg/mg to 1.84mg/mg. While in stepwise intercalation process, the adsorption of LYZ was obviously lower than that in direct intercalation experiment, indicating that the exchange reaction between lysozyme and POP-D2000 was incomplete in the stepwise intercalation reaction.

Styles APA, Harvard, Vancouver, ISO, etc.

41

Katahira, Shin-Ichiro, Kenji Yasue et M. Inagaki. « Intercalation of ε-caprolactam Ions into Inorganic Hosts ». Journal of Materials Research 14, n^o 4 (avril 1999) : 1178–80. http://dx.doi.org/10.1557/jmr.1999.0157.

Texte intégral

Résumé :

The intercalation reaction of ε-caprolactam anion (ε–CL-) into hydrotalcite heated up to 500 °C to expel in its double hydroxide gallery and also that of ε-caprolactam cation (ε–CL+) into mica were successfully performed in their aqueous solutions. The intercalation reaction of ε–CL- into 500 °C heated hydrotalcite was completed within 1 h at 60 °C, and the resultant intercalation compound had the interlayer spacing of 0.77 nm. The intercalation of ε–CL+ into mica, on the other hand, proceeded rather slowly in two steps, which was due to the presence of two species, Na+ and hydrated Na+ in the mica gallery, and gave the intercalation compound with the interlayer spacing of 1.47 nm.

Styles APA, Harvard, Vancouver, ISO, etc.

42

Li, Xiao Xia, Ji Jin Zhao et De Yue Ma. « Preparation and Characteristics of Highly Expandable Graphite Intercalation Compounds by Two-Step Chemical Intercalation ». Key Engineering Materials 703 (août 2016) : 278–83. http://dx.doi.org/10.4028/www.scientific.net/kem.703.278.

Texte intégral

Résumé :

Graphite intercalation compounds (GIC) are the most common precursors for expanded graphites which are promising materials for many applications. A series of GICs with different expanding volumes (EV) were prepared by a two-step chemical intercalation way. Effects of the input of oxidant and intercalating agent on the EV of GICs were discussed. The microstructures and morphologies of graphites before and after intercalation were analylized by X-ray diffraction and scanning electron microscope, respectively. The results show that the GIC with an EV of 600 ml⋅g-1 may be prepared under temperal conditions by a two-step intercalation way. The interlayer spacing of the pre-GIC formeded by one-step intercalation is a bit larger than that of natural graphites, while the interlayer spacing of the GIC obtained by two-step intercalation becomes much larger than that of the pre-GIC because of secondery intercalation. When the d-spacing (d002) value of the GIC rises from 0.3590 nm up to 0.3711nm, its EV increases from 267 up to 600 ml⋅g-1 due to the decomposition and release of much more intercalated substances during a thermal shock.

Styles APA, Harvard, Vancouver, ISO, etc.

43

Li, Jihui, Huiqing Shi, Ning Li, Mei Li et Jing Li. « Facile preparation of graphite intercalation compounds in alkali solution ». Open Chemistry 8, n^o 4 (1 août 2010) : 783–88. http://dx.doi.org/10.2478/s11532-010-0048-5.

Texte intégral

Résumé :

AbstractGraphite intercalation compounds are often prepared by flake graphite, oxidants, inorganic acids, organic acids and intercalated ions which are usually hydrogen protons between the graphene planes. They are also known as the acid-treated graphite intercalation compounds. In this work, alkaline graphite intercalation compounds were prepared by flake graphite, K2Cr2O7, concentrated H2SO4 and NaOH, and the morphology and structure were characterized by Electron microscopy and X-ray techniques. The results display that the combination of neutralisation heat and oxidation capability produced by K2Cr2O7 can break the bonds to produce the spaces between the graphene planes and hydroxyl ions also intercalate into the graphene planes to form alkaline graphite intercalation compounds in alkali solution. The morphology and structure of alkaline graphite intercalation compounds are analogous to the ones of the acid-treated graphite intercalation compounds, but the intercalated ions and the expansion volume are different. The results show that the method is an innovation.

Styles APA, Harvard, Vancouver, ISO, etc.

44

Lepienski, C. M., M. S. Meruvia, W. Veiga et F. Wypych. « Mechanical properties of niobium disulfide and its hydrated sodium cation intercalation compound ». Journal of Materials Research 15, n^o 10 (octobre 2000) : 2061–64. http://dx.doi.org/10.1557/jmr.2000.0296.

Texte intégral

Résumé :

Mechanical properties of 2H–NbS2 and its intercalation derivative Nax(H2O)yNbS2 were measured by using nanoindentation techniques. The intercalation chemical process was conducted in solution and the cation–hydrated derivative produced was [Nax(H2O)yNbS2]. It was observed that the intercalation process occurs through the crystal edges producing a wave intercalation's front that moved as the reaction proceeded. The hardness and elastic modulus presented very low values in the intercalated region. The load × displacement curves from nanoindentation tests suggested that intercalation of hydrated sodium ions through the edges caused layer separation even in the nonintercalated region at the center of the crystal. It is important to emphasize that no similar studies were found in the literature about this theme. Intercalation process is very important in several areas, like solid-state batteries, and mechanical properties of these kinds of materials are not completely understood. This study is a new approach to understanding the mechanical behavior of layered materials submitted to an intercalation process.

Styles APA, Harvard, Vancouver, ISO, etc.

45

Franco, F., et M. D. Ruiz Cruz. « Factors influencing the intercalation degree (‘reactivity’) of kaolin minerals with potassium acetate, formamide, dimethylsulphoxide and hydrazine ». Clay Minerals 39, n^o 2 (juin 2004) : 193–205. http://dx.doi.org/10.1180/0009855043920130.

Texte intégral

Résumé :

AbstractFactors influencing the degree of intercalation (‘reactivity’) of kaolinite group minerals have been investigated using six kaolin minerals, with variable crystallinity and particle size. Tests were performed to measure the degree of intercalation with potassium acetate, formamide, dimethylsulphoxide and hydrazine.These experiments indicate that intercalation degree depends on a number of factors, including particle size, degree of ordering, type of guest molecules, method of intercalation, and presence and types of impurities. Anew method for determination of the degree of intercalation is proposed, which is not dependent on the intensity of complex reflections. The results indicate that formamide is the most sensitive reagent to distinguish differently ordered kaolin minerals whereas hydrazine appears as the most appropriate reagent to differentiate kaolin minerals from other 7 Å phases.

Styles APA, Harvard, Vancouver, ISO, etc.

46

Inagaki, Michio, et Masahiko Ohira. « Intercalation of AlCl3 into FeCl3-graphite intercalation compounds and occurrence of BI-intercalation ». Carbon 31, n^o 5 (1993) : 777–81. http://dx.doi.org/10.1016/0008-6223(93)90015-3.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

47

Benito, P., F. M. Labajos, P. Moreno et W. Jones. « Preparación de un nuevo material híbrido orgánico/inorgánico mediante la intercalación de colina en bronce de molibdeno ». Boletín de la Sociedad Española de Cerámica y Vidrio 43, n^o 2 (30 avril 2004) : 426–28. http://dx.doi.org/10.3989/cyv.2004.v43.i2.559.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

48

Abe, Takeshi, Yasuo Mizutani, Eiji Ihara, Mitsuru Asano et Toshio Harada. « Preparation of FeCl3–IBr–H2SO4–graphite multi-intercalation compounds ». Journal of Materials Research 9, n^o 2 (février 1994) : 377–82. http://dx.doi.org/10.1557/jmr.1994.0377.

Texte intégral

Résumé :

Stages 4-6 FeCl3-graphite intercalation compounds (GIC's) have been prepared by an ordinary two-bulb method, and FeCl3-IBr-graphite bi-intercalation compounds (GBC's) are synthesized by holding the FeCl3-GIC's in the saturated vapor of IBr. The x-ray diffraction patterns of the FeCl3-IBr-GBC's obtained from stages 4, 5, and 6 FeCl3-GIC's give the stacking sequences as G(FeCl3)GG(IBr)GG(FeCl3)G, G(FeCl3)GG(IBr)GGG(FeCl3)G, and G(FeCl3)GG(IBr)GG(IBr)GG(FeCl3)G, respectively, where G, (FeCl3), and (IBr) refer to the graphite, FeCl3, and IBr layers, respectively. The multi-intercalation of H2SO4 into the FeCl3-IBr-GBC's synthesized from stages 4 and 6 FeCl3-GIC's occurs at all the vacant galleries of the GBC's at the same time. In contrast, the multi-intercalation of H2SO4 into the FeCl3-IBr-GBC obtained from the stage 5 FeCl3-GIC takes place in two processes. The first multi-intercalation occurs at the gallery adjacent to the bi-intercalated IBr layer, and the stacking sequence of the resulting graphite multi-intercalation compound is determined to be G(FeCl3)GG(IBr)G(H2SO4)GG(FeCl3)G, where (H2SO4) refers to the H2SO4 layer. The second multi-intercalation occurs at all the rest of the vacant galleries.

Styles APA, Harvard, Vancouver, ISO, etc.

49

Liu, Qingxin, Limei Wu, Xiaolong Wang, Ling Hu, Lili Gao, Yuanbiao Hu et Ning Tang. « Study on preparation and mechanism of organic montmorillonite with different functional groups ». AIP Advances 12, n^o 4 (1 avril 2022) : 045108. http://dx.doi.org/10.1063/5.0085139.

Texte intégral

Résumé :

The influence of functional groups on the organic intercalation of montmorillonite (Mt) was discussed in this article by intercalating Mt with four organic compounds containing different cationic functional groups. The maximum intercalation amounts of hexadecyl trimethyl ammonium bromide (CTAB), benzylcetyldimethyl ammonium chloride (HDBAC), bromohexadecyl pyridine (HIB), and 1-hexadecyl-3-methylimidazolium chloride (HMC) were 0.96, 0.81, 0.73, and 0.61 mmol/g, respectively. Molecular simulations revealed that the functional groups influenced the arrangement status of organic cations in the Mt interlayers. It found out that the minimum distances between the nitrogen atom in CTAB, HDBAC, HIB, and HMC and the surface oxygen of Mt were 2.939 ± 0.05, 2.554 ± 0.11, 3.703 ± 0.07, and 3.360 ± 0.08 Å, respectively. Molecular size was also shown to influence intercalation since CTAB was more easily intercalated than the larger HDBAC. Moreover, the benzene ring in HDBAC weakened the interaction between its chains, which decreased its intercalation amount. The –N+ functional groups of HIB and HMC were located on the benzene ring, which weakened their cationic exchange ability. In summary, the functional groups affected the intercalation amount, intercalation rate, and their arrangement (parallel or vertical) in Mt. These results were used to explore the intercalation mechanism of Mt, which can be used to guide the production of novel organic Mt compounds.

Styles APA, Harvard, Vancouver, ISO, etc.

50

Shcherbinina, E., A. Iakovleva, Y. Gavrilov, O. Golovanova et N. Muzylev. « Lower Eocene sedimentary succession and microfossil biostratigraphy in the central northern Caucasus basin ». Geologica Acta 18 (29 janvier 2020) : 1–15. http://dx.doi.org/10.1344/geologicaacta2020.18.1.

Texte intégral

Résumé :

The lower Eocene sediments from the classical Paleogene section exposed along the Kheu River, northern Caucasus, southern Russia are here studied. This ca. 50m thick succession is lithologically contrasting: the lower and upper parts are composed by soft marls separated by a thick Radiolaria-rich unit of non-calcareous and low-calcareous mudstones with intercalations of compact cherty layers. According to nannofossil and dinocyst biostratigraphy, the unique intercalation of Total Organic Carbon (TOC)-rich sediment (sapropelitic bed) in the lower part of the lower Eocene correspond to the Paleocene-Eocene Thermal Maximum (PETM) and a series of sapropelitic interlayers in the upper marly part of the lower Eocene succession correlates with the Early Eocene Climatic Optimum (EECO). The study of nannofossil and dinocyst assemblages enabled detailed zonal subdivision and first-order calibration of nannofossil and dinocyst bio-events during this time-span. The studied interval of the section embraces the complete succession of nannofossil zones NP9-NP13 of Martini, 1971, CP8-CP11 of Okada and Bukry, 1980 and CNP11-CNE5 of Agnini et al., 2014. By means of dinocyst stratigraphy, the succession of Apectodinium hyperacanthum, Axiodinium augustum, Deflandrea oebisfeldensis, Dracodinium astra, Stenodinium meckelfeldense, Dracodinium varielongitudum, Ochetodinium romanum/Samlandia chlamydophora and Areosphaeridium diktyoplokum zones are identified in the Ypresian part of the Kheu section.

Styles APA, Harvard, Vancouver, ISO, etc.

Articles de revues sur le sujet « Intercalatton »

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres