scholarly journals Study of the Structure and Antimicrobial Activity of Ca-Deficient Ceramics on Chlorhexidine Nanoclay Substrate

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2996 ◽  
Author(s):  
Lenka Pazourková ◽  
Magda Reli ◽  
Marianna Hundáková ◽  
Erich Pazdziora ◽  
Daniela Predoi ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Effect ◽  
Precipitation Process ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Bacteria And Fungi

Novel biomedical composites, based on organically modified vermiculite and montmorillonite with deposited Ca-deficient hydroxyapatite (CDH), were prepared. The monoionic sodium forms of vermiculite and montmorillonite were intercalated with chlorhexidine diacetate (CA). The surfaces of organoclays were used for the precipitation of Ca-deficient hydroxyapatite. The composites with Ca-deficient hydroxyapatite showed very good antibacterial effects, similar to the antimicrobial activity of pure organoclay samples. Better antibacterial activity was shown in the organically modified montmorillonite sample with Ca-deficient hydroxyapatite compared with the vermiculite composite, but, in the case of Staphylococcus aureus, both composites showed the same minimum inhibitory concentration (MIC) value. The antimicrobial effect of composites against bacteria and fungi increased with the time of exposure. The structural characterization of all the prepared materials, performed using X-ray diffraction and FT infrared spectroscopy analysis, detected no changes in the original clay or CDH during the intercalation or precipitation process, therefore we expect the strength of the compounds to be in the original power.

Preparation, Physical and Mechanical Characterization of Montmorillonite/Polyethylene Nanocomposites

2006 ◽  
Vol 312 ◽  
pp. 205-210 ◽  
Author(s):  
V. Pettarin ◽  
Victor Jayme Roget Rodriguez Pita ◽  
Francisco Rolando Valenzuela-Díaz ◽  
S. Moschiar ◽  
L. Fasce ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Clay Platelet ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified

In this paper, we report the preparation of polyethylene composites with organically modified montmorillonite. Three different Na+-montmorillonites were modified in order to obtain organoclays and two grades of high-density polyethylene were used as composite matrices. All composites were prepared by melt blending, and their physical and mechanical properties were thoroughly characterized. The extent of clay platelet exfoliation in the composites was confirmed by X-ray diffraction (XRD). Mechanical properties under static and impact conditions were evaluated to assess the influence of the reinforcement on the properties of polyethylene.

Modification and characterization of montmorillonite fillers used in composites with vulcanized natural rubber

2009 ◽  
Vol 63 (1) ◽  
Author(s):  
Jana Hrachová ◽  
Ivan Chodák ◽  
Peter Komadel
Keyword(s):  
Adsorbed Water ◽  
Organic Cations ◽  
Basal Spacing ◽  
X Ray Diffraction ◽  
Surface Areas ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Xrd Patterns

AbstractParent Ca-montmorillonite (Jelšový Potok, Slovakia, Ca-JP) and Na-montmorillonite Kunipia-F (Japan, Na-KU) were ion-exchanged with octadecyltrimethylammonium (ODTMA) cations. Characteristics of the samples were studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (IR) and thermogravimetry (TG). Surface areas were measured by sorption of N2 and ethyleneglycol monoethyl ether. Scanning electron microscopy photographs (SEM) were used to characterize the texture of samples. The XRD patterns show that, upon intercalation, the basal spacing of montmorillonite is expanded and corresponds to the pseudotrimolecular arrangement of organic cations in the interlayers. The IR spectra of organically modified montmorillonite show C-H stretching and bending bands of both CH3 and CH2 groups in the 3000–2800 cm−1 and 1500–1400 cm−1 region, respectively. Modification of montmorillonite by organic cations decreased the hydrophilicity of their mineral surface and adsorbed water evaporated at lower temperatures. The SEM photographs reveal a tendency towards lump formation and agglomeration of the ODTMA-montmorillonite particles. The modification introducing organic moiety lead to a substantial decrease in the surface area of both montmorillonites; however, it remained remarkably high, being at the level typical for silica. Completely characterized fillers were used to prepare rubber compositions with enhanced physical properties, as described in Hrachová et al. (2008).

Thermal characterization of organically modified montmorillonite

2001 ◽  
Vol 367-368 ◽  
pp. 339-350 ◽  
Author(s):  
Wei Xie ◽  
Zongming Gao ◽  
Kunlei Liu ◽  
Wei-Ping Pan ◽  
Richard Vaia ◽  
...  
Keyword(s):  
Thermal Characterization ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified

Optimisation of the ceramic-like body for ceramifiable EVA-based composites

2017 ◽  
Vol 24 (4) ◽  
pp. 599-607 ◽  
Author(s):  
Xinhao Gong ◽  
Tingwei Wang
Keyword(s):  
Ceramic Body ◽  
Ethylene Vinyl Acetate ◽  
Melt Blending ◽  
Red Phosphorus ◽  
X Ray Diffraction ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Dense Ceramic ◽  
Acetate Copolymer

AbstractVarious ceramifiable ethylene-vinyl acetate copolymer (EVA) composites were prepared by melt blending with two kinds of glass frits, organically modified montmorillonite (OMMT) and whitened and capsulised red phosphorus (WCRP). The influence of different filler components and firing temperatures on the ceramifiable properties of the composites was studied. The dripping behaviour of the composites was analyzed by a vertical burning test. The microstructure of the residues was characterised by X-ray diffraction (XRD) and scanning electron microscopy. The results showed that the optimised EVA composite was free of melt dripping during burning with the addition of OMMT. A dimensionally stable and dense ceramic residue was also obtained, especially with the addition of WCRP. It was suggested that new phases were formed at firing temperatures, and WCRP could promote the formation of ceramic body which was not fused during firing at 900°C as evidenced by XRD.

scholarly journals Synergistic Effect of Hybridized Cellulose Nanocrystals and Organically Modified Montmorillonite on κ-Carrageenan Bionanocomposites

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 874 ◽  
Author(s):  
Siti Zakuwan ◽  
Ishak Ahmad
Keyword(s):  
Synergistic Effect ◽  
Water Uptake ◽  
Cellulose Nanocrystals ◽  
Food Packaging ◽  
Filler Loading ◽  
X Ray Diffraction ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
And Performance

The synergistic effect of using κ-carrageenan bionanocomposites with the hybridization of cellulose nanocrystals (CNCs) and organically modified montmorillonite (OMMT) reinforcements was studied. The effects of different reinforcements and filler contents were evaluated through mechanical testing, and morphological and water uptake properties. The tensile strength and Young’s modulus of both bionanocomposites increased with filler loading and optimized at 4%. OMMT incorporation into the κ-carrageenan/CNCs bionanocomposites resulted in further mechanical property improvement with an optimum ratio of 1:1 (CNCs:OMMT) while maintaining high film transparency. X-ray diffraction and morphological analyses revealed that intercalation occurred between the κ-carrageenan bionanocomposite matrix and OMMT. The water uptake of the κ-carrageenan bionanocomposites was significantly reduced by the addition of both CNCs and OMMT. The enhancements in the mechanical properties and performance of the hybrid bionanocomposite indicate compatibility among the reinforcement, biopolymer, and well-dispersed nanoparticles. This renders the hybrid CNC/OMMT/κ-carrageenan nanocomposites extremely promising for food packaging applications.

Effects of Surface Properties of Montmorillonite for their Cytocompatibility

2016 ◽  
Vol 696 ◽  
pp. 80-84 ◽  
Author(s):  
Ko Nakanishi ◽  
Shigeaki Abe ◽  
Shuichi Yamagata ◽  
Yasuhiro Yoshida ◽  
Junichiro Iida
Keyword(s):  
Coupling Reaction ◽  
Diffraction Peak ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Silane Coupling ◽  
Organically Modified ◽  
Size And Morphology

We modified the surface of organically modified montmorillonite (OMMT) with the carboxyl group using the silane coupling reaction and assessed its characteristics and cytocompatibility. Scanning electron microscope observations show that while the size and morphology of the obtained OMMT (OMMT-COOH) was unchanged, the surface of OMMT-COOH was coarser than that of OMMT. Fourier transform infrared spectra showed characteristic strong peaks at 1210 and 1630 cm−1, corresponding to the peaks of the carboxyl group. X-ray diffraction analysis showed that the diffraction peak of OMMT-COOH corresponding to the (001) reflection was located at higher a 2θ value than that of OMMT. Results of the proliferation ratio and cell viability measurements indicated that the OMMT-COOH cytocompatibility is higher than that of OMMT. Based on these results, we conclude that cytocompatibility of montmorillonite would be improved by tuning the properties of the surface.

TG characterization of organically modified montmorillonite

2004 ◽  
Vol 75 (2) ◽  
pp. 671-676 ◽  
Author(s):  
V.L. P. Soares ◽  
R. S. V. Nascimento ◽  
V. J. Menezes ◽  
L. Batista
Keyword(s):  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified

Thermomechanical behavior of nanoclay filled TPU/PP blends

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
M. Kannan ◽  
S.S. Bhagawan ◽  
Kuruvilla Joseph ◽  
Sabu Thomas
Keyword(s):  
Hard Segment ◽  
Thermoplastic Polyurethane ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Modifier ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Pp Blends

AbstractBoth ester- and ether- based thermoplastic polyurethane (TPU) nanocomposites were prepared by melt blending, using 3 wt % Cloisite 10A (organically modified montmorillonite clay) as the nanoscale reinforcement. The nanocomposites were subsequently melt-blended with polypropylene (PP) using maleic anhydride grafted polypropylene (MA-g-PP) as a compatibilizer (in the ratio of 70/30- TPU nano/PP, 70/25/5-TPU nano/PP/MA-g-PP). Besides giving substantial increase in modulus, tensile strength and other properties organoclay reinforcement functions as a surface modifier for TPU hard segment. X-ray diffraction studies revealed that compatibilization is further improved by introducing functionalized PP (MA-g-PP) in the organoclay containing blends. The blend system was evaluated by DSC, DMA, SEM, mechanical properties and Xray diffraction. The results indicate that the ester- TPU exhibited greater miscibility than ether-TPU. Abrasion resistance and water absorption were also better for compatibilised ester- TPU blends as compared to the ether-TPU materials.

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