scholarly journals Pickering emulsions stabilized by some inorganic materials

2021 ◽  
pp. 30-49
Author(s):  
Akbota Adilbekova ◽  
Ayaulym Yertayeva
Keyword(s):  
Colloidal Particles ◽  
Metal Oxide Nanoparticles ◽  
Inorganic Materials ◽  
Pickering Emulsions ◽  
Inorganic Particles ◽  
Carbon Particles ◽  
Inorganic Substances ◽  
Wide Range ◽  
Calcium Compounds ◽  
Clay Materials

The paper presents studies of various solid stabilizers of emulsions based on inorganic materials. Inorganic colloidal particles have an advantage for obtaining of stable emulsions due to their safety for use in food, cosmetics, pharmaceutical industry and medicine. Pickering emulsions have a higher biodegradability compared to classical emulsions stabilized with surfactants. An overview of inorganic substances such as silicon dioxide, clay materials, metal and metal oxide nanoparticles, calcium compounds and carbon particles used for stabilizing of Pickering emulsions is considered. A variety of solid inorganic particles as well as modification of their surfaces by surfactants allows to obtain the stable Pickering emulsions of different types for a wide range of applications. It should be noted that despite a large number of studies, this class of disperse systems is still not studied fully; various methods of their preparation and influence of solid particle size on stability and size of emulsions droplets are shown.

Inorganic-Polymer Nanocomposites for Optical Applications

2006 ◽  
Author(s):  
H. Du ◽  
S. H. Ng ◽  
K. T. Neo ◽  
M. Ng ◽  
I. S. Altman ◽  
...  
Keyword(s):  
Surface Modification ◽  
Optical Sensors ◽  
Protective Coatings ◽  
Functional Materials ◽  
Optical Data Storage ◽  
Inorganic Materials ◽  
Planar Waveguides ◽  
Optical Data ◽  
Inorganic Particles ◽  
Wide Range

The combination of organic and inorganic materials forms unique composites with properties that neither of the two components provides. Such functional materials are considered innovative advanced materials that enable applications in many fields, including optics, electronics, separation membranes, protective coatings, catalysis, sensors, biotechnology, and others. The challenge of incorporating inorganic particles into an organic matrix still remains today, especially for nanoparticles, due to the difficulties in their dispersion, de-agglomeration and surface modification. NanoGram has pioneered a nanomaterials synthesis technology based on laser pyrolysis process to produce a wide range of crystalline nanomaterials including complex metal oxides, nitrides and sulfides and with precisely controlled compositions, crystal structure, particle size and size distributions. In this paper we will present some examples of nanocomposites prepared using different polymer host materials and phase-pure rutile TiO2. The inorganic component can be dispersed at higher 50 weight percent into the polymer matrix. We have demonstrated a 0.2–0.3 increase of refractive index in the composite over that of host polymer while maintaining high optical transparency. These nanocomposites can be used in a range of applications or optical devices, such as planar waveguides, flat panel displays, optical sensors, high-brightness LEDs, diffraction gratings and optical data storage. Experimental data on TiO2 nanoparticle characterization, dispersion technique, surface modification and will be presented and nanocomposite properties discussed.

How to use alum with cationic dispersed rosin size

TAPPI Journal ◽  
2016 ◽  
Vol 15 (5) ◽  
pp. 331-335 ◽  
Author(s):  
LEBO XU ◽  
JEREMY MYERS ◽  
PETER HART
Keyword(s):  
Zeta Potential ◽  
Colloidal Particles ◽  
Streaming Potential ◽  
Excessive Amount ◽  
Paper Machine ◽  
Optimum Amount ◽  
Potential Measurement ◽  
Streaming Current ◽  
Wide Range ◽  
Laboratory Results

Retention of cationic dispersed rosin size was studied via turbidity measurements on stock filtrate with different alum and dispersed rosin size dosages. Stock charge characteristics were analyzed using both an analysis of charge demand determined via a streaming current detector and an evaluation of zeta potential of the fibers by streaming potential measurement. The results indicated that an optimum amount of alum existed such that good sizing retention was maintained throughout a wide range of dispersed rosin size dosages. However, when an excessive amount of alum was used and fines and colloidal particles were transitioned from anionic to cationic, the cationic size retention was reduced. Laboratory results were confirmed with a paper machine trial. All data suggested that a stock charge study was necessary to identify optimal alum dosage for a cationic dispersed rosin sizing program.

Recent advances in the design of inorganic and nano-clay particles for the treatment of brain disorders

2021 ◽  
Author(s):  
Francesca Persano ◽  
Svetlana Batasheva ◽  
Gölnur Fakhrullina ◽  
Giuseppe Gigli ◽  
Stefano Leporatti ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Silica Nanoparticles ◽  
Biomedical Applications ◽  
Inorganic Materials ◽  
Brain Disorders ◽  
Clay Particles ◽  
Recent Advances ◽  
Wide Range ◽  
Nano Clay

Inorganic materials, in particular nanoclays and silica nanoparticles, have attracted enormous attention due to their versatile and tuneable properties, making them ideal candidates for a wide range of biomedical applications, such as drug delivery.

scholarly journals ADSORBATIVE SEPARATION OF DOXYCYCLINE FROM AQUEOUS SOLUTION WITH N,N-DIETHYL N-METHYL CHITOSAN, GUM AND POLYACRYLIC ACID BASED HYDROGELS

2021 ◽  
Vol 11 (07) ◽  
pp. 44-53
Author(s):  
Mirvari Hasanova Mirvari Hasanova
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Zeta Potential ◽  
Polyacrylic Acid ◽  
Inorganic Materials ◽  
Biologically Active ◽  
Cross Linking ◽  
Separation And Purification ◽  
Inorganic Substances ◽  
The Cross

The separation and purification of antibiotics with sorption by ion-exchange materials, as well as their delivery in biological processes by immobilization, are now widely used in biotechnology. There are many scientific studies in the literature on the sorption of antibiotics by polymer-based sorbents and inorganic materials, as well as the study of thermodynamics and kinetics of the process. In the literature, the acquisition of biologically active systems from the sorption of antibiotics by ion-exchange fibers based on various polymers and inorganic substances was carried out. However, the synthesis of selective gels for the effective separation of doxycycline and its delivery in different pH mediums by sorption with biodegradable, biocompatible polysaccharide-containing composites is one of the topical issues. Gel was synthesized from the cross-linking of N,N-diethyl N-methyl derivative of a natural polyaminosaccharide of chitosan by glutaric aldehyde. Also, pH-sensitive hydrogels that can swollen in water were synthesized from the cross-linking of a graft copolymer of cherry source gummiarabic with N-vinylpyrrolidone, as well as synthetic polymer polyacrylic acid with N,N-methylene-bis-acrylamide. The structure of the gels were identified by FTIR and NMR spectroscopy, and the sorption of doxycycline antibiotic from an aqueous solution was investigated. According to the values of zeta potential, the protonation of functional groups in the main macromolecule in an acidic medium leads to a value of zeta potential of 40÷80 mV on the surface of chitosan-based gel and others. Although the chemical structure is different, the isoelectric point is set around pH=6÷8 for all three hydrogels. The dependences of the sorption process on the amount of gels, antibiotic concentration, temperature, and pH medium were studied. The experimental data were analyzed using two adsorption models, Langmuir and Freundlich, with the later system providing the best fit. Doxycycline is adsorbed on the surface of chitosan, gummiarabic and polyacrylic acid based hydrogel composite through by physical interactions. Also, the results of thermodynamic parameters ΔG40 kJ/mol show that the nature of the adsorption process is physical, and spontaneous, too. Keywords: Chitosan, Gummiarabic-arabinogalactane, polyacrylic acid, hydrogel, sorption isoterms, doxycycline, thermodynamica.

scholarly journals Bio-Templating: An Emerging Synthetic Technique for Catalysts. A Review

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1364
Author(s):  
M. Carmen Herrera-Beurnio ◽  
Jesús Hidalgo-Carrillo ◽  
Francisco J. López-Tenllado ◽  
Juan Martin-Gómez ◽  
Rafael C. Estévez ◽  
...  
Keyword(s):  
Active Sites ◽  
Experimental Studies ◽  
Functional Materials ◽  
Inorganic Materials ◽  
Hierarchical Organization ◽  
Materials Synthesis ◽  
Energy Capture ◽  
Wide Range ◽  
Mineralization Processes ◽  
And Storage

In the last few years, researchers have focused their attention on the synthesis of new catalyst structures based on or inspired by nature. Biotemplating involves the transfer of biological structures to inorganic materials through artificial mineralization processes. This approach offers the main advantage of allowing morphological control of the product, as a template with the desired morphology can be pre-determined, as long as it is found in nature. This way, natural evolution through millions of years can provide us with new synthetic pathways to develop some novel functional materials with advantageous properties, such as sophistication, miniaturization, hybridization, hierarchical organization, resistance, and adaptability to the required need. The field of application of these materials is very wide, covering nanomedicine, energy capture and storage, sensors, biocompatible materials, adsorbents, and catalysis. In the latter case, bio-inspired materials can be applied as catalysts requiring different types of active sites (i.e., redox, acidic, basic sites, or a combination of them) to a wide range of processes, including conventional thermal catalysis, photocatalysis, or electrocatalysis, among others. This review aims to cover current experimental studies in the field of biotemplating materials synthesis and their characterization, focusing on their application in heterogeneous catalysis.

scholarly journals Prospects of Biocatalyst Purification Enroute Fermentation Processes

2021 ◽  
Author(s):  
Michael Bamitale Osho ◽  
Sarafadeen Olateju Kareem
Keyword(s):  
Fermentation Process ◽  
Colloidal Particles ◽  
Methyl Cellulose ◽  
Industrial Applications ◽  
Maximum Activity ◽  
Inorganic Materials ◽  
Organic Substrates ◽  
Ammonium Sulphate Precipitation ◽  
Sodom Apple ◽  
Microbial Agents

Biotransformation of broth through fermentation process suffers a major setback when it comes to disintegration of organic substrates by microbial agents for industrial applications. These biocatalysts are in crude/dilute form hence needs to be purified to remove colloidal particles and enzymatic impurities thus enhancing maximum activity. Several contractual procedures of concentrating dilute enzymes and proteins had been reported. Such inorganic materials include ammonium sulphate precipitation; salting, synthetic polyacrylic acid; carboxy-methyl cellulose, tannic acid, edible gum and some organic solvents as precipitants etc. The emergence of organic absorbents such as sodom apple (Calostropis procera) extract, activated charcoal and imarsil had resulted in making significant impact in industrial circle. Various concentrations of these organic extracts have been used as purifying agents on different types of enzyme vis: lipase, amylase, protease, cellulase etc. Purification fold and stability of the enzyme crude form attained unprecedented results.

LASER FLUORESCENCE OF SAND AND CLAY MATERIALS

1977 ◽  
Vol 57 (1) ◽  
pp. 1-8
Author(s):  
A. R. MACK ◽  
E. J. BRACH
Keyword(s):  
Grain Size ◽  
Fluorescence Spectra ◽  
Laser Energy ◽  
Average Power ◽  
Laser Fluorescence ◽  
Regression Estimate ◽  
Airborne Laser ◽  
Wide Range ◽  
Fineness Of Grain ◽  
Clay Materials

Samples of granular materials illuminated with a 20 m Watt (average power) laser energy source at a wavelength of 337.1 nm differed in their fluorescence spectra over a wide range of wavelengths from approximately 380 to 660 nm. The fluorescent yield was usually higher with increased fineness of grain size and with increased concentration of clay (> 10% of under 2-μ grain size). However, sandy soils containing a low content of clay (i.e. < 10%) had a higher yield than the regression estimate. Modifying the fluorosensor for greater resolution at a higher energy level (1 nm bandwidth and 25 m Watt average power) resulted in eight discernible peaks between 384 and 440 nm, at 486 and at 550 nm. Overall fluorescence was markedly increased by removal of Fe coatings from the surface of the grains by a dithionite treatment. Thus, laser-induced fluorescence spectra obtained from various partially vegetated land areas by airborne laser fluorosensing may be influenced by the granular material associated with non-vegetated "open" areas.

Engineering functional alginate beads for encapsulation of Pickering emulsions stabilized by colloidal particles

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101267-101276 ◽  
Author(s):  
Hongshan Liang ◽  
Bin Zhou ◽  
Jing Li ◽  
Yun He ◽  
Yaqiong Pei ◽  
...  
Keyword(s):  
Sustained Release ◽  
Colloidal Particles ◽  
Alginate Beads ◽  
Delivery Systems ◽  
Pickering Emulsions ◽  
Pharmaceutical Industries ◽  
Hydrophilic Compounds

Pickering emulsions are widely used as delivery systems in food, cosmetics, and pharmaceutical industries for the encapsulation and sustained release of hydrophilic compounds.

scholarly journals A comparison of the radiosensitisation ability of 22 different element metal oxide nanoparticles using clinical megavoltage X-rays

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Alexandra Guerreiro ◽  
Nicholas Chatterton ◽  
Eleanor M. Crabb ◽  
Jon P. Golding
Keyword(s):  
Dna Damage ◽  
Metal Oxide ◽  
Hydroxyl Radical ◽  
Singlet Oxygen ◽  
Hydroxyl Radicals ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
X Rays ◽  
X Ray ◽  
Wide Range

Abstract Background A wide range of nanoparticles (NPs), composed of different elements and their compounds, are being developed by several groups as possible radiosensitisers, with some already in clinical trials. However, no systematic experimental survey of the clinical X-ray radiosensitising potential of different element nanoparticles has been made. Here, we directly compare the irradiation-induced (10 Gy of 6-MV X-ray photon) production of hydroxyl radicals, superoxide anion radicals and singlet oxygen in aqueous solutions of the following metal oxide nanoparticles: Al2O3, SiO2, Sc2O3, TiO2, V2O5, Cr2O3, MnO2, Fe3O4, CoO, NiO, CuO, ZnO, ZrO2, MoO3, Nd2O3, Sm2O3, Eu2O3, Gd2O3, Tb4O7, Dy2O3, Er2O3 and HfO2. We also examine DNA damage due to these NPs in unirradiated and irradiated conditions. Results Without any X-rays, several NPs produced more radicals than water alone. Thus, V2O5 NPs produced around 5-times more hydroxyl radicals and superoxide radicals. MnO2 NPs produced around 10-times more superoxide anions and Tb4O7 produced around 3-times more singlet oxygen. Lanthanides produce fewer hydroxyl radicals than water. Following irradiation, V2O5 NPs produced nearly 10-times more hydroxyl radicals than water. Changes in radical concentrations were determined by subtracting unirradiated values from irradiated values. These were then compared with irradiation-induced changes in water only. Irradiation-specific increases in hydroxyl radical were seen with most NPs, but these were only significantly above the values of water for V2O5, while the Lanthanides showed irradiation-specific decreases in hydroxyl radical, compared to water. Only TiO2 showed a trend of irradiation-specific increase in superoxides, while V2O5, MnO2, CoO, CuO, MoO3 and Tb4O7 all demonstrated significant irradiation-specific decreases in superoxide, compared to water. No irradiation-specific increases in singlet oxygen were seen, but V2O5, NiO, CuO, MoO3 and the lanthanides demonstrated irradiation-specific decreases in singlet oxygen, compared to water. MoO3 and CuO produced DNA damage in the absence of radiation, while the highest irradiation-specific DNA damage was observed with CuO. In contrast, MnO2, Fe3O4 and CoO were slightly protective against irradiation-induced DNA damage. Conclusions Beyond identifying promising metal oxide NP radiosensitisers and radioprotectors, our broad comparisons reveal unexpected differences that suggest the surface chemistry of NP radiosensitisers is an important criterion for their success.

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