scholarly journals Physicochemical Characterization of Natural Wollastonite and Calcite

Minerals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 228 ◽  
Author(s):  
Murat Olgaç Kangal ◽  
Gülay Bulut ◽  
Onur Guven
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Chemical Stability ◽  
Raw Materials ◽  
Physicochemical Characterization ◽  
Contact Angles ◽  
Thermal Resistivity ◽  
Bright Color ◽  
High Alkalinity

Wollastonite and calcite minerals are significant raw materials and are extensively used due to their unique properties. Wollastonite is used in plastics, paint, ceramics, paper, resins, and in construction as a substitution for asbestos due to its chemical stability, thermal resistivity, needle-like shape, and brightness. Calcite is one of the most used raw materials because of its low hardness, high alkalinity, sorptive properties, white and bright color. Wollastonite and calcite are two minerals found together in nature. The most common method used for separating these two minerals is flotation. In this study, the surface properties of pure mineral samples were investigated. The pH profiles of both minerals were obtained by measuring the surface charge of particles followed by the measurement of the zeta potential in different collector concentrations. The wettability of minerals was examined by measuring their contact angles.

CHARACTERIZATION OF A SURFACE-CHARGE MODULATION ELECTROFLUIDIC TRANSISTOR BY HYDRODYNAMIC MEASUREMENTS

2012 ◽  
Vol 11 (04) ◽  
pp. 1240021
Author(s):  
GUILLAUME LAFFITE ◽  
XU ZHENG ◽  
LOUIS RENAUD ◽  
FRANÇOIS BESSUEILLE ◽  
ELISABETH CHARLAIX ◽  
...  
Keyword(s):  
Experimental Study ◽  
Zeta Potential ◽  
Surface Charge ◽  
Gate Voltage ◽  
Silica Surface ◽  
Insulating Layer ◽  
Charge Regulation ◽  
Charge Modulation ◽  
Gating Effect

We present an experimental study on the electrofluidic transistor in this paper. A novel and easy way to integrate the transistor into a microchannel is developed. The performances of the insulating layer, especially the leakage current under gate voltage, are carefully characterized. The change of surface charge on silica surface by gate polarization is measured, however, by measuring the streaming current, the gating effect on zeta potential has not been observed. This result should imply new assumption in the understanding of the charge regulation in the electrical double layer under gate polarization.

Mineralogical and physicochemical characterization of selected Portuguese Mesozoic-Cenozoic muddy/clayey raw materials to be potentially used as healing clays

Clay Minerals ◽  
2010 ◽  
Vol 45 (2) ◽  
pp. 229-240 ◽  
Author(s):  
M. Rebelo ◽  
F. Rocha ◽  
E. Ferreira Da Silva
Keyword(s):  
Physicochemical Properties ◽  
Mineral Water ◽  
Raw Materials ◽  
Physicochemical Characterization ◽  
Mineralogical Composition ◽  
Exchange Capacity ◽  
Water Mixture ◽  
X Ray Diffraction ◽  
Geological Formations

AbstractThe use of pelitic geological materials for the treatment of muscle-bone-skin pathologies, by application of a cataplasm made of clay and mineral water mixture, is currently receiving attention and interest from the general public and scientific community. In Portugal there are several natural occurrences of clays/muds which are used for pelotherapy and/or geotherapy. These are carried out either indoors (thalassotherapy and thermal centres) or outdoors, in natural sites generally located near the seaside. The aim of this study is to assess the mineralogical and physicochemical properties of Portuguese raw materials for therapeutic purposes. These materials were collected from different Portuguese Mesozoic-Cenozoic geological formations located in the neighbourhood of thermal centres or at beaches known from their empirical applications. X-ray diffraction (XRD) and scanning electron microscopy (SEM-EDS) were used to assess the mineralogical composition of these clays. Physicochemical properties, such as specific surface area, cation exchange capacity, plasticity/abrasiveness indices and heat diffusiveness were also determined. Having distinct geological ages and genesis, the materials examined are mainly illitic. Less abundant kaolinite and smectite are also present. With respect to their physicochemical properties, all samples have good thermal properties which make them potentially suitable for therapeutic or aesthetic purposes.

Characterization of surface charge and zeta potential of colloidal silica prepared by various methods

2014 ◽  
Vol 31 (11) ◽  
pp. 2088-2093 ◽  
Author(s):  
Gyeong Sook Cho ◽  
Dong-Hyun Lee ◽  
Hyung Mi Lim ◽  
Seung-Ho Lee ◽  
Chongyoup Kim ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Surface Charge ◽  
Colloidal Silica

scholarly journals Fabrication of Native and Enzymatically Modified Durian Seed (Durio zibethinus Murr.) Starch

2019 ◽  
Vol 1 (2) ◽  
Author(s):  
Susi Afrianti Rahayu ◽  
Nasrul Wathoni ◽  
Sriwidodo Sriwidodo ◽  
Lisa Sophianingsih
Keyword(s):  
Raw Materials ◽  
Starch Content ◽  
Physicochemical Characterization ◽  
Ash Content ◽  
Enzyme Extract ◽  
Durio Zibethinus ◽  
High Starch Content ◽  
Durian Seed ◽  
Starch Production

Durian seed (Durio zibethinus Murr.) has a high starch content (46.2%) and thus can be used as a new source of starch for the raw materials of pharmaceutical and food industries. In this study, we fabricated native and enzymatically modified durian seed starch using a rough enzyme extract from Saccharomycopsis fibuligera. Wet grinding method was used for starch production. Physicochemical characterization of the starches was investigated by organoleptic, acidity-basicity, loss on drying,  flow capability, compressibility, ash content and microbial limit. In addition, viscoamylograph had been done to clarify the viscosity properties of the starches. The result of starch production showed that the durian seed had a starch yield of 17.68%. Physicochemical characterization of the starch showed that the results of quality testing had fulfilled the Indonesian Pharmacopoeia 4th edition standards requirements, such as description, identification, acidity-basicity, loss on drying, ash content and microbial limit. In addition, viscoamylograph study showed that the enzymatically modified durian seed starch had a higher viscosity than the native durian seed starch. Interestingly, modification of the durian seed starch using a rough enzyme extract improved its flow capability and compressibility. These results suggest that the modified durian seed starch experienced an increase in viscosity, compressibility and flow capability compared to native durian starch.  Keywords: durian, seed, starch, enzymatic modification

scholarly journals Preparation and physicochemical characterization of Eudragit® RL100 Nanosuspension with potential for Ocular Delivery of Sulfacetamide

2010 ◽  
Vol 13 (4) ◽  
pp. 510 ◽  
Author(s):  
Bivash Mandal ◽  
Kenneth S Alexander ◽  
Alan T Riga
Keyword(s):  
Zeta Potential ◽  
Bacterial Infections ◽  
Room Temperature ◽  
In Vitro Release ◽  
Physicochemical Characterization ◽  
Entrapment Efficiency ◽  
Scanning Calorimetry ◽  
Freeze Dried ◽  
Drug Entrapment Efficiency

Purpose: Polymeric nanosuspension was prepared from an inert polymer resin (Eudragit® RL100) with the aim of improving the availability of sulfacetamide at the intraocular level to combat bacterial infections. Methods: Nanosuspensions were prepared by the solvent displacement method using acetone and Pluronic® F108 solution. Drug to polymer ratio was selected as formulation variable. Characterization of the nanosupension was performed by measuring particle size, zeta potential, Fourier Transform infrared spectra (FTIR), Differential Scanning Calorimetry (DSC), Powder X-Ray Diffraction (PXRD), drug entrapment efficiency and in vitro release. In addition, freeze drying, redispersibility and short term stability study at room temperature and at 40C were performed. Results: Spherical, uniform particles (size below 500 nm) with positive zeta potential were obtained. No significant chemical interactions between drug and polymer were observed in the solid state characterization of the freeze dried nanosuspension (FDN). Drug entrapment efficiency of the selected batch was increased by changing the pH of the external phase and addition of polymethyl methacrylate in the formulation. The prepared nanosuspension exhibited good stability after storage at room temperature and at 40C. Sucrose and Mannitol were used as cryoprotectants and exhibited good water redispersibility of the FDN. Conclusion: The results indicate that the formulation of sulfacetamide in Eudragit® RL100 nanosuspension could be utilized as potential delivery system for treating ocular bacterial infections.

scholarly journals Solid Lipid Nanoparticles (SLNs) with Potential as Cosmetic Hair Formulations Made from Otoba Wax and Ultrahigh Pressure Homogenization

Cosmetics ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 42 ◽  
Author(s):  
Sandra Rubiano ◽  
Juan D. Echeverri ◽  
Constain H. Salamanca
Keyword(s):  
Zeta Potential ◽  
Solid Lipid Nanoparticles ◽  
Physicochemical Characterization ◽  
Lipid Nanoparticles ◽  
Ultrahigh Pressure ◽  
Solid Lipid ◽  
Internal Phase ◽  
Microbiological Stability ◽  
Intermediate Chains

The development and physicochemical characterization of solid lipid nanoparticles (SLNs) with potential for formulating hair cosmetic products were carried out. SLNs were made from Otoba wax, which is native to the tropical Andean region and has a high chemical composition of fatty acids with intermediate chains. SLNs were formulated by preparing wax-in-water dispersions at two internal phase proportions (low = 5% w/w and high = 20% w/w), using the same ratio of surfactant system and preservatives. The coarse dispersions were subjected to ultrahigh pressure homogenization (UHPH), and thermal stability assays for 4 weeks were carried out, where changes in Creaming Index, droplet size, polydispersity, viscosity, zeta potential, conductivity, and pH were evaluated. The results showed that Otoba wax has a required HLB value around 9 and is mainly composed of lauric (~35%) and myristic (~45%), which have been reported to improve the condition of hair loss. Regarding the development on SLNs, it was found that the internal phase concentration did not considerably affect the physicochemical and microbiological properties. Likewise, it was found that UHPH enabled the production of SLNs with particle sizes <200 nm, low polydispersity (<0.3), high zeta potential values, and suitable physical and microbiological stability. Therefore, Otoba wax has potential for the development of SLNs applicable to cosmetic formulations, especially for hair products.

scholarly journals Mechanical and Microstructure Properties of Biochar-Based Mortar: An Internal Curing Agent for PCC

2019 ◽  
Vol 11 (9) ◽  
pp. 2491 ◽  
Author(s):  
Rayane Mrad ◽  
Ghassan Chehab
Keyword(s):  
Construction Industry ◽  
Raw Materials ◽  
Physicochemical Characterization ◽  
Partial Replacement ◽  
Alternative Material ◽  
Open Dumping ◽  
Environmentally Friendly Process ◽  
Guidelines And Recommendations ◽  
Biomass Decomposition

In pursuing sustainability targets, the construction industry has witnessed significant efforts exerted on exploring new alternatives for raw materials. Such initiatives aim to alleviate concerns of overexploitation of natural resources leading to their depletion. On a different note, the disposal of municipal solid waste (MSW) has also become a major concern in some countries, such as the case of Lebanon, where illegal dumping continues to take its toll on the environment. Pyrolysis has been introduced as a biomass decomposition process of MSW and is considered an environmentally friendly process that can mitigate open dumping. However, pyrolysis produces significant amounts of biochar as a byproduct that in turn needs to be disposed of or treated. This research aims to investigate the viability of using biochar as a sustainable alternative material to sand in cementitious mortar composites. A thorough microscale physicochemical characterization of the biochar is conducted prior to its inclusion in mortar. Then, its incorporation as a partial replacement of sand in mortar is assessed at the mesoscale level, based on performance indices that included compressive strength and microstructure properties. Analysis of the experimental results are used to provide guidelines and recommendations as to the effective incorporation of biochar fraction in cementitious mortar.

scholarly journals Physicochemical Characterization of Packaging Foils Coated by Chitosan and Polyphenols Colloidal Formulations

2020 ◽  
Vol 21 (2) ◽  
pp. 495 ◽  
Author(s):  
Lidija Fras Zemljič ◽  
Olivija Plohl ◽  
Alenka Vesel ◽  
Thomas Luxbacher ◽  
Sanja Potrč
Keyword(s):  
Surface Charge ◽  
Elemental Composition ◽  
Chitosan Nanoparticles ◽  
Physicochemical Characterization ◽  
Surface Characteristics ◽  
Nanoparticle Dispersions ◽  
Physico Chemical ◽  
Additive Formulation ◽  
Uv Ozone

In this research, antimicrobial polysaccharide chitosan was used as a surface coating for packaging material. The aim of our research was to establish an additive formulation of chitosan and antioxidative plant extracts as dispersion of nanoparticles. Chitosan nanoparticles with embedded thyme, rosemary and cinnamon extracts were synthesized, and characterized for this purpose. Two representative, commercially used foils, polypropylene (PP) and polyethylene (PE), previously activated by UV/ozone to improve coating adhesion, were functionalized using chitosan-extracts nanoparticle dispersions. The foils were coated by two layers. A solution of macromolecular chitosan was applied onto foils as a first layer, followed by the deposition of various extracts embedded into chitosan nanoparticles that were attached as an upper layer. Since active packaging must assure bioactive efficiency at the interface with food, it is extremely important to understand the surface characteristics and phenomena of functionalized foils. The physico-chemical analyses of functionalized foils were thus comprised of surface elemental composition, surface charge, wettability, as well as surface morphology. It has been shown that coatings were applied successfully with an elemental composition, surface charge and morphology that should enable coating stability, homogeneity and consequently provide an active concept of the packaging surface in contact with food. Moreover, the wettability of foils was improved in order to minimize the anti-fogging behavior.

Introducing Electrospray as a Potent Technique to Deliver Chitosan/pDNA Nanoparticles to Eukaryotic Cells

2021 ◽  
Vol 66 ◽  
pp. 73-84
Author(s):  
Farzaneh Saeedi Landi ◽  
Babak Negahdari ◽  
Fariba Esmaeili ◽  
Sedigheh Kolivand ◽  
Amir Amani
Keyword(s):  
Zeta Potential ◽  
Transfection Efficiency ◽  
Low Cost ◽  
Gene Transfection ◽  
Physicochemical Characterization ◽  
Entrapment Efficiency ◽  
Ratio Size ◽  
Agarose Electrophoresis ◽  
One Step

Electrospray technique has received increasing attentions for intracellular gene delivery as well as production of nanoparticles. In this study, chitosan/pDNA nanoparticles with N/P ratio of 5 were prepared and transferred to HEK293T cells by electrospray technique. Physicochemical characterization of prepared nanoparticles, including size, zeta potential and entrapment efficiency was performed and attachment of pDNA to chitosan was confirmed by gel agarose electrophoresis. Moreover, transfection efficiency was investigated using flow cytometry. MTT assay was performed for cell viability studies. Nanoparticles were prepared at three pDNA concentrations of 10, 55 and 100 μg/ml in fixed N/P ratio. Size of nanoparticles was obtained as 110, 188 and 240 nm, using DLS. SEM showed size of 102.34 ± 10.66 nm for samples having 55 μg/ml pDNA. Zeta potential and entrapment efficiency were +25 mv and 85±4%m respectively. The effect of pDNA concentration, electrospray time and incubation time on transfection efficiency was investigated using Box-Behnken design. Percent of GFP-positive cells was 41.05 ± 3.04% which was taken as an indicator of transfection efficiency. Transfection efficiency of this method was then compared with that of calcium phosphate (31.1 ± 2.4%), showing improved efficiency. Considering the fact that electrospray is an easy, low cost, one-step process which makes low damage to cells and produces monodispersed nanoparticles, the method is introduced as a fascinating approach in gene transfection.

Physicochemical characterization of raw materials and co-products from the titanium dioxide industry

2009 ◽  
Vol 166 (2-3) ◽  
pp. 1429-1440 ◽  
Author(s):  
M.J. Gázquez ◽  
J.P. Bolívar ◽  
R. García-Tenorio ◽  
F. Vaca
Keyword(s):  
Titanium Dioxide ◽  
Raw Materials ◽  
Physicochemical Characterization
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