Effects of Ultrasound on Zinc Oxide/Vermiculite/Chlorhexidine Nanocomposite Preparation and Their Antibacterial Activity

Microbial infection and biofilm formation are both problems associated with medical implants and devices. In recent years, hybrid organic-inorganic nanocomposites based on clay minerals have attracted significant attention due to their application potential in the field of antimicrobial materials. Organic drug/metal oxide hybrids exhibit improved antimicrobial activity, and intercalating the above materials into the interlayer of clay endows a long-term and controlled-release behavior. Since antimicrobial activity is strongly related to the structure of the material, ultrasonic treatment appears to be a suitable method for the synthesis of these materials as it can well control particle size distribution and morphology. This study aims to prepare novel, structurally stable, and highly antimicrobial nanocomposites based on zinc oxide/vermiculite/chlorhexidine. The influence of ultrasonic treatment at different time intervals and under different intercalation conditions (ultrasonic action in a breaker or in a Roset’s vessel) on the structure, morphology, and particle size of prepared hybrid nanocomposite materials was evaluated by the following methods: scanning electron microscopy, X-ray diffraction, energy dispersive X-ray fluorescence spectroscopy, carbon phase analysis, Fourier transforms infrared spectroscopy, specific surface area measurement, particle size analysis, and Zeta potential analysis. Particle size analyses confirmed that the ultrasonic method contributes to the reduction of particle size, and to their homogenization/arrangement. Further, X-ray diffraction analysis confirmed that ultrasound intercalation in a beaker helps to more efficiently intercalate chlorhexidine dihydrochloride (CH) into the vermiculite interlayer space, while a Roset’s vessel contributed to the attachment of the CH molecules to the vermiculite surface. The antibacterial activity of hybrid nanocomposite materials was investigated on Gram negative (Escherichia coli, Pseudomonas aeruginosa) and Gram positive (Staphylococcus aureus, Enterococcus faecalis) bacterial strains by finding the minimum inhibitory concentration. All hybrid nanocomposite materials prepared by ultrasound methods showed high antimicrobial activity after 30 min, with a long-lasting effect and without being affected by the concentration of the antibacterial components zinc oxide (ZnO) and CH. The benefits of the samples prepared by ultrasonic methods are the rapid onset of an antimicrobial effect and its long-term duration.

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Stability of Malayaite Pigments in High-ZnO Ceramic Glazes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.772.90 ◽

2018 ◽

Vol 772 ◽

pp. 90-94

Author(s):

Niti Yongvanich ◽

Chanakan Chanthanan ◽

Nattanit Ruennarong ◽

Natthaya Suwanna

Keyword(s):

Particle Size ◽

Zinc Oxide ◽

Chemical Stability ◽

Interfacial Layer ◽

Preferential Orientation ◽

X Ray Diffraction ◽

X Ray ◽

Color Parameters ◽

Microstructural Alterations

This study examined the chemical stability of malayaite pigments in ceramic glazes containing high amounts of zinc oxide (ZnO). The calcined pigments were embedded in a molten glaze which is basically corrosive glass. Within the glaze, ZnO has been known among potters to be undesirable as some pigments are not stable in glazes containing ZnO. The synthesized pigments’ particle size ranges from 4 to 18 μm without dominant preferential orientation. Their colors were in the red and yellow tones. Chemical stability between the pigments and glazes was tested using X-ray Diffraction (XRD). Slight changes were observed. Increasing amounts of ZnO resulted in an interfacial layer of approximately 50 μm between the crystalline pigment and surrounding amorphous glaze. The a color parameters gradually decreased while the b parameters switched to a negative value. The resulting glazes evolved from maroon to pale violet. The correlation between color and microstructural alterations was discussed.

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Morphology, Structure and Particle Size of Hybrid Nanozinc Oxide

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.728.204 ◽

2017 ◽

Vol 728 ◽

pp. 204-208

Author(s):

Tanapak Metanawin ◽

Praripatsaya Panutumrong ◽

Siripan Metanawin

Keyword(s):

Particle Size ◽

Zinc Oxide ◽

Miniemulsion Polymerization ◽

Polymer Materials ◽

X Ray Diffraction ◽

X Ray ◽

Nano Zinc Oxide ◽

Oxide Particles ◽

Zinc Oxide Particles ◽

Nano Zinc

The hybrid polymer materials of nano-zinc oxide were synthesized via miniemulsion polymerization technique. Zinc oxide nanoparticles were encapsulated by polystyrene to introduce multi-function to the hybrid nano-zinc oxide. The contents of zinc oxide particles in the hybrid nano-zinc oxide were various from 1wt% to 40wt%. The particles sizes of hybrid nano-zinc oxide were determined by using dynamic light scattering. It was showed that the particle size of the hybrid nano-zinc oxide was in the range of 124-205nm. Scanning electron microscopy was employed to determine the topography and morphology of hybrid nano-zinc oxide. The crystal structure of hybrid nano-zinc oxide were explored by X-ray diffraction spectroscopy.

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Hybrid Quinoline-Sulfonamide Complexes (M2+) Derivatives with Antimicrobial Activity

Molecules ◽

10.3390/molecules25122946 ◽

2020 ◽

Vol 25 (12) ◽

pp. 2946 ◽

Cited By ~ 1

Author(s):

Dumitrela Diaconu ◽

Violeta Mangalagiu ◽

Dorina Amariucai-Mantu ◽

Vasilichia Antoci ◽

Cristian Levente Giuroiu ◽

...

Keyword(s):

Antimicrobial Activity ◽

Antibacterial Activity ◽

Antifungal Activity ◽

Inhibitory Concentration ◽

X Ray Diffraction ◽

Metal Acetate ◽

X Ray ◽

Good Antibacterial Activity ◽

Inhibition Zones ◽

Antibacterial And Antifungal

Two new series of hybrid quinoline-sulfonamide complexes (M2+: Zn2+, Cu2+, Co2+ and Cd2+) derivatives (QSC) were designed, synthesized and tested for their antimicrobial activity. The synthesis is straightforward and efficient, involving two steps: acylation of aminoquinoline followed by complexation with metal acetate (Cu2+, Co2+ and Cd2+) or chloride (Zn2+). The synthesized QSC compounds were characterized by FTIR and NMR spectroscopy and by X-ray diffraction on single crystal. The QSC compounds were preliminary screened for their antibacterial and antifungal activity and the obtained results are very promising. In this respect, the hybrid N-(quinolin-8-yl)-4-chloro-benzenesulfonamide cadmium (II), considered as leading structure for further studies, has an excellent antibacterial activity against Staphylococcus aureus ATCC25923 (with a diameters of inhibition zones of 21 mm and a minimum inhibitory concentration (MIC) of 19.04 × 10−5 mg/mL), a very good antibacterial activity against Escherichia coli ATCC25922 (with a diameters of inhibition zones of 19 mm and a MIC of 609 × 10−5 mg/mL), and again an excellent antifungal activity against Candida albicans ATCC10231 (with a diameters of inhibition zones of 25 mm and a MIC of 19.04 × 10−5 mg/mL).

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Ultrasound-Assisted Preparation, Characterization, and Antibacterial Activity of Montmorillonite Modified by ε-Polylysine Hydrochloride

Materials ◽

10.3390/ma12244148 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4148

Author(s):

Xinfu Yuan ◽

Jinli Zhang ◽

Rui Zhang ◽

Jingyuan Liu ◽

Wentao Wang ◽

...

Keyword(s):

Antibacterial Activity ◽

Ultrasonic Treatment ◽

Interlayer Space ◽

X Ray Diffraction ◽

X Ray ◽

Higher Power ◽

Dimethylammonium Chloride ◽

Suitable Amount ◽

Ultrasound Assisted ◽

Application Fields

In this study, two types of antibacterial montmorillonites (Mt) were prepared using a facile method. The Mt modified with ε-polylysine hydrochloride (ε-PL) was named PL-Mt, while the Mt dually modified with dioctadecyl dimethylammonium chloride (D1821) and ε-PL was named PL-OMt. The results of the X-ray diffraction, Fourier-transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) of the PL-Mt indicated that 30% ε-PL was the most suitable amount for intercalating the Mt. The particle size and distribution of the ε-PL in the solution demonstrated that the Mt d-value could not be further increased owing to the increasing ε-PL diameter. The result of the X-ray diffraction of PL-OMt displayed that ultrasonic treatment at 600 W facilitated ε-PL to intercalate into the OMt interlayer space. The PL-OMt prepared with ultrasonic treatment at 600 W exhibited antibacterial activity against Escherichia coli and Bacillus subtilis superior to that of the PL-OMt prepared with higher-power ultrasonic treatment. Thus, the addition of 30% ε-PL based on the dry Mt mass is the most suitable ratio for preparing PL-Mt, while ultrasonic treatment at 600 W is the most suitable for preparing PL-OMt. These findings may expand the application fields of ε-PL.

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Dilatometer Studies of Pigment-Rubber Systems

Rubber Chemistry and Technology ◽

10.5254/1.3540000 ◽

1941 ◽

Vol 14 (1) ◽

pp. 113-124 ◽

Cited By ~ 3

Author(s):

H. C. Jones ◽

H. A. Yiengst

Keyword(s):

Particle Size ◽

Zinc Oxide ◽

Particle Surface ◽

X Ray Diffraction ◽

Vacuole Formation ◽

X Ray ◽

Rubber Compounds ◽

Large Particles ◽

Complete Study ◽

Particle Size And Shape

Abstract A number of years ago Schippel observed that, when certain pigmented rubber stocks were stretched, there was a reduction in specific gravity of the compound. This he attributed to the separation of the rubber from the pigment, resulting in vacuole formation. Green confirmed Schippel's explanation with the aid of a microscope. He prepared photomicrographs of stretched rubber films showing the formation of vacuoles at coarse pigment particles and undispersed pigment acting as single large particles. These vacuoles were conical in shape, and extended from one or both sides of the particles in the direction of elongation. Depew and Easley reported microscopic results relating particle surface and particle size and shape to the formation of vacuoles in stretched rubber. Several years ago Holt and McPherson designed a dilatometer to measure the volume change of rubber compounds under tension. In stretching gum-rubber bands, they noted a decrease in volume, which they ascribed to the fibering of the rubber, and an increase in volume of pigmented rubber bands, which they explained by the formation of vacuoles around the pigment particles. Furthermore these investigators pointed out that the decrease in volume of rubber on stretching is influenced by the same considerations as the x-ray diffraction, since it is observed only above a certain critical elongation and is greater the higher the elongation, the lower the temperature, and the longer the time the sample is kept stretched. Holt and McPherson dealt almost entirely with gum stocks except that they included measurements on a whiting and a carbon black stock. The object of this investigation was to extend the work of Holt and McPherson to a more complete study of pigmented stocks, with particular reference to those compounded with zinc oxide.

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Investigation of Phase, Purity, Morphology and Particle Size of Zn(1-x)CuxO Materials via X-Ray Diffraction (XRD) and Microscopic Techniques

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.895.343 ◽

2014 ◽

Vol 895 ◽

pp. 343-346

Author(s):

Muhd Firdaus Kasim ◽

Norlida Kamarulzaman ◽

Suraya Ahmad Kamil

Keyword(s):

Particle Size ◽

Zinc Oxide ◽

Metal Oxides ◽

Chelating Agents ◽

X Ray Diffraction ◽

Soft Chemistry ◽

Phase Purity ◽

X Ray ◽

Heavily Doped ◽

Microscopic Techniques

Substitution of cations in metal oxides result in differences of materials characteristics. Substitution resulting in isostructural materials is not easy. In this work, Cu has been used as the substitution element for Zn in Zinc oxide. The Zn(1-x)CuxO (x=0.01, 0.02, 0.03, 0.04, 0.05) materials were prepared via a simple soft chemistry method without using any chelating agents. Results showed that some of the samples are pure but the heavily doped samples contain a very small amount of CuO as an impurity. XRD and microscopy results agree with each other.

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Mining Wastes of an Albite Deposit as Raw Materials for Vitrified Mullite Ceramics

Minerals ◽

10.3390/min11030232 ◽

2021 ◽

Vol 11 (3) ◽

pp. 232

Author(s):

Pedro J. Sánchez-Soto ◽

Eduardo Garzón ◽

Luis Pérez-Villarejo ◽

George N. Angelopoulos ◽

Dolores Eliche-Quesada

Keyword(s):

Particle Size ◽

Raw Materials ◽

Phase Evolution ◽

Particle Size Analysis ◽

Size Analysis ◽

Mining Wastes ◽

X Ray Diffraction ◽

X Ray ◽

Maximum Value

In this work, an examination of mining wastes of an albite deposit in south Spain was carried out using X-ray Fluorescence (XRF), X-ray diffraction (XRD), particle size analysis, thermo-dilatometry and Differential Thermal Analysis (DTA) and Thermogravimetric (TG) analysis, followed by the determination of the main ceramic properties. The albite content in two selected samples was high (65–40 wt. %), accompanied by quartz (25–40 wt. %) and other minor minerals identified by XRD, mainly kaolinite, in agreement with the high content of silica and alumina determined by XRF. The content of Na2O was in the range 5.44–3.09 wt. %, being associated with albite. The iron content was very low (<0.75 wt. %). The kaolinite content in the waste was estimated from ~8 to 32 wt. %. The particle size analysis indicated values of 11–31 wt. % of particles <63 µm. The ceramic properties of fired samples (1000–1350 °C) showed progressive shrinkage by the thermal effect, with water absorption and open porosity almost at zero at 1200–1250 °C. At 1200 °C, the bulk density reached a maximum value of 2.38 g/cm3. An abrupt change in the phase evolution by XRD was found from 1150 to 1200 °C, with the disappearance of albite by melting in accordance with the predictions of the phase diagram SiO2-Al2O3-Na2O and the system albite-quartz. These fired materials contained as main crystalline phases quartz and mullite. Quartz was present in the raw samples and mullite was formed by decomposition of kaolinite. The observation of mullite forming needle-shape crystals was revealed by Scanning Electron Microscopy (SEM). The formation of fully densified and vitrified mullite materials by firing treatments was demonstrated.

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Enhancing carbonation and chloride resistance of autoclaved concrete by incorporating nano-CaCO3

Nanotechnology Reviews ◽

10.1515/ntrev-2020-0078 ◽

2020 ◽

Vol 9 (1) ◽

pp. 998-1008

Author(s):

Guo Li ◽

Zheng Zhuang ◽

Yajun Lv ◽

Kejin Wang ◽

David Hui

Keyword(s):

Cement Hydration ◽

Mercury Intrusion Porosimetry ◽

Hardened Concrete ◽

Optimal Dosage ◽

Hydration Products ◽

X Ray Diffraction ◽

Carbonation Depth ◽

X Ray ◽

Chloride Resistance

AbstractThree nano-CaCO3 (NC) replacement levels of 1, 2, and 3% (by weight of cement) were utilized in autoclaved concrete. The accelerated carbonation depth and Coulomb electric fluxes of the hardened concrete were tested periodically at the ages of 28, 90, 180, and 300 days. In addition, X-ray diffraction, thermogravimetry, and mercury intrusion porosimetry were also performed to study changes in the hydration products of cement and microscopic pore structure of concrete under autoclave curing. Results indicated that a suitable level of NC replacement exerts filling and accelerating effects, promotes the generation of cement hydration products, reduces porosity, and refines the micropores of autoclaved concrete. These effects substantially enhanced the carbonation and chloride resistance of the autoclaved concrete and endowed the material with resistances approaching or exceeding that of standard cured concrete. Among the three NC replacement ratios, the 3% NC replacement was the optimal dosage for improving the long-term carbonation and chloride resistance of concrete.

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Synthesis of magnesium carbonate hydrate from natural talc

Open Chemistry ◽

10.1515/chem-2020-0154 ◽

2020 ◽

Vol 18 (1) ◽

pp. 951-961

Author(s):

Qiuju Chen ◽

Tao Hui ◽

Hongjuan Sun ◽

Tongjiang Peng ◽

Wenjin Ding

Keyword(s):

Crystal Structure ◽

Particle Size ◽

Crystal Growth ◽

Crystal Morphology ◽

Magnesium Carbonate ◽

Organic Additives ◽

X Ray Diffraction ◽

Morphological Transformation ◽

X Ray ◽

Carbonation Process

AbstractVarious morphologies of magnesium carbonate hydrate had been synthesized without using any organic additives by carefully adjusting the reaction temperature and time during the talc carbonation process. At lower temperatures, magnesium carbonate hydrate was prone to display needle-like morphology. With the further increase of the carbonation temperature, the sheet-like crystallites became the preferred morphology, and at higher aging temperatures, these crystallites tended to assemble into layer-like structures with diverse morphologies, such as rose-like particles and nest-like structure. The reaction time had no effect on the crystal morphology, but it affected the particle size and situation of the crystal growth. X-Ray diffraction results showed that these various morphologies were closely related to their crystal structure and compositions. The needle-like magnesium carbonate hydrate had a formula of MgCO3·3H2O, whereas with the morphological transformation from needle-like to sheet-like, rose-like, and nest-like structure, their corresponding compositions also changed from MgCO3·3H2O to 4MgCO3·Mg(OH)2·8H2O, 4MgCO3·Mg(OH)2·5H2O, and 4MgCO3·Mg(OH)2·4H2O.

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Synthesis and Characterization of Clay Polymer Nanocomposites of P(4VP-co-AAm) and Their Application for the Removal of Atrazine

Polymers ◽

10.3390/polym11040721 ◽

2019 ◽

Vol 11 (4) ◽

pp. 721 ◽

Cited By ~ 3

Author(s):

Jorge A. Ramírez-Gómez ◽

Javier Illescas ◽

María del Carmen Díaz-Nava ◽

Claudia Muro-Urista ◽

Sonia Martínez-Gallegos ◽

...

Keyword(s):

Polymer Nanocomposites ◽

Nanocomposite Materials ◽

Synthesis And Characterization ◽

Cross Linking ◽

X Ray Diffraction ◽

Numerous Species ◽

X Ray ◽

Different Types ◽

Synthesized Materials

Atrazine (ATZ) is an herbicide which is applied to the soil, and its mechanism of action involves the inhibition of photosynthesis. One of its main functions is to control the appearance of weeds in crops, primarily in corn, sorghum, sugar cane, and wheat; however, it is very toxic for numerous species, including humans. Therefore, this work deals with the adsorption of ATZ from aqueous solutions using nanocomposite materials, synthesized with two different types of organo-modified clays. Those were obtained by the free radical polymerization of 4-vinylpyridine (4VP) and acrylamide (AAm) in different stoichiometric ratios, using tetrabutylphosphonium persulfate (TBPPS) as a radical initiator and N,N′-methylenebisacrylamide (BIS) as cross-linking agent. The structural, morphological, and textural characteristics of clays, copolymers, and nanocomposites were determined through different analytical and instrumental techniques, i.e., X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Adsorption kinetics experiments of ATZ were determined with the modified and synthesized materials, and the effect of the ratio between 4VP and AAm moieties on the removal capacities of the obtained nanocomposites was evaluated. Finally, from these sets of experiments, it was demonstrated that the synthesized nanocomposites with higher molar fractions of 4VP obtained the highest removal percentages of ATZ.

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