scholarly journals Physicochemical, Spectroscopic and Rheological Characterization of Anacardium occidentale gum Exudates

2019 ◽  
pp. 1-15
Author(s):  
Nnabuk Okon Eddy ◽  
Inemesit Udofia ◽  
Edward Okey ◽  
Anduang O. Odiongenyi ◽  
Patrick Udofia
Keyword(s):  
Physicochemical Analysis ◽  
Anacardium Occidentale ◽  
Rheological Characteristics ◽  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Rheological Characterization ◽  
Average Value ◽  
Irregular Shapes ◽  
Plant Gums

Anacardium occidentale gum exudate was analyzed for physicochemical, spectroscopic and rheological characteristics. Physicochemical analysis revealed that the gum is mildly acidic, ionic, extremely rich in carbohydrate and calcium. GCMS spectrum revealed the presence of some carboxylic acids, ketone and alkanes. The FTIR spectrum of the gum closely resembled those of other polysaccharides. Scanning electron micrograph revealed the presence of pores containing particles with irregular shapes. The average value of intrinsic viscosity of the gum was 3.28 dL/g, which compared favourably with those obtained for some plant gums. From the Huggins, Kraemer and Power law models, it was deduced that there is absence of molecular association and that the conformation of the gum is more rod like. Viscosity of the studied gum was found to be greatly influenced by the presence of urea, K+, Ca2+ and Al2+. Anarcadium occidentale gum exhibited a non-Newtonian property with characteristics dilatant and shears thickening properties.

Preparation and Characterization of a Novel Mixed Functional Cationic Exchange Copolymer Microsphere as Drug Carrier

2012 ◽  
Vol 476-478 ◽  
pp. 2288-2291 ◽  
Author(s):  
Kaewnapa Wongsermsin ◽  
Praneet Opanasopit ◽  
Tanasait Ngawhirunpat ◽  
Prasert Akkaramongkolporn
Keyword(s):  
Drug Carrier ◽  
Gastric Ph ◽  
The Novel ◽  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Cationic Exchange ◽  
The Fourier Transform ◽  
Release Characteristic ◽  
Dextromethorphan Hydrobromide

The objective of the present study was to prepare a novel mixed functional cationic exchange copolymer microsphere containing methyl methacrylic acid and sulfonated styrene crosslinked with divinylbenzene. The emulsion polymerization was used to prepare the cationic exchange copolymer microsphere which was characterized by the scanning electron micrograph (SEM) and the fourier transform infrared spectroscopy (FTIR). The release characteristic of the loaded drug i.e. dextromethorphan hydrobromide from the copolymer microsphere was studied under both simulated gastric (pH 1.2) and intestinal (pH 6.8) conditions. The result showed that the drug released from the novel copolymer microsphere depended on the pH of the release media.

scholarly journals Rheological Characterization of Alginate Based Hydrogels for Tissue Engineering

MRS Advances ◽  
2017 ◽  
Vol 2 (24) ◽  
pp. 1309-1314 ◽  
Author(s):  
Pengfei Duan ◽  
Nehir Kandemir ◽  
Jiajun Wang ◽  
Jinju Chen
Keyword(s):  
Mechanical Properties ◽  
Drug Delivery ◽  
Tissue Engineering ◽  
Drug Delivery Systems ◽  
Rheological Characteristics ◽  
Scaffold Material ◽  
Rheological Characterization ◽  
Frequency Sweep ◽  
Strain Sweep

ABSTRACTHydrogels have been widely used in many applications from tissue engineering to drug delivery systems. For both tissue engineering and drug delivery, the mechanical properties are important because they would affect cell-materials interactions and injectability of drugs encapsulated in hydrogel carriers. Therefore, it is important to study the mechanical properties of these hydrogels, particularly at physiological temperature (37°C). This study adopted strain sweep and frequency sweep rotational rheological tests to investigate the rheological characteristics of various tissue engineering relevant hydrogels with different concentrations at 37°C. These hydrogels include alginate, RGD-alginate, and copolymerized collagen/alginate/fibrin. It has revealed that the addition of RGD has negligible effect on the elastic modulus and viscosity of alginate. Alginate gels have demonstrated shear thinning behavior which indicates that they are suitable candidates as carriers for cells or drug delivery. The addition of collagen and fibrin would reinforce the mechanical properties of alginate which makes it a strong scaffold material.

scholarly journals Characterization of Silica Particles and Concentration Dependent Adsorption Study of Biomolecules

1970 ◽  
Vol 45 (4) ◽  
pp. 363-366
Author(s):  
MA Rahman ◽  
MAJ Miah ◽  
H Ahmad
Keyword(s):  
Ph Value ◽  
Xrd Analysis ◽  
Silica Particles ◽  
Adsorption Behavior ◽  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Oh Groups ◽  
Adsorption Study ◽  
Isoelectric Ph

Submicron-sized silica particles were initially characterized by scanning electron micrograph, FTIR spectroscopy and XRD analysis. The observations revealed that the highly dispersed amorphous silica particles were relatively monodispersed and the particles surface was covered with hydrogen bonded OH groups. Relatively higher magnitude of adsorption of cationic emulsifier and coagulation of silica particles suggested that particles were negatively charged. A comparative study of adsorption behavior of different biomolecules such as trypsin, albumin and lysozyme was also done at the respective isoelectric pH value. The magnitude of adsorption increased with the increase in the amount of immobilization per unit mass of silica particles. Key words: Silica; Amorphous; Adsorption behavior; Emulsifier; Biomolecules DOI: 10.3329/bjsir.v45i4.7377 Bangladesh J. Sci. Ind. Res. 45(4), 363-366, 2010

Analytical and High-Resolution EM Study of Crystalline Phases formed at Metal-Ceramic Interface

1990 ◽  
Vol 48 (2) ◽  
pp. 426-427
Author(s):  
N. Merk ◽  
A. P. Tomsia ◽  
G. Thomas
Keyword(s):  
Cross Section ◽  
Dissimilar Materials ◽  
Ceramic Materials ◽  
Electron Micrograph ◽  
Scanning Electron Micrograph ◽  
Structural Applications ◽  
Metal Ceramic ◽  
The Subject ◽  
Ceramic Compounds ◽  
Scanning Electron

A recent development of new ceramic materials for structural applications involves the joining of ceramic compounds to metals. Due to the wetting problem, an interlayer material (brazing alloy) is generally used to achieve the bonding. The nature of the interfaces between such dissimilar materials is the subject of intensive studies and is of utmost importance to obtain a controlled microstructure at the discontinuities to satisfy the demanding properties for engineering applications . The brazing alloy is generally ductile and hence, does not readily fracture. It must also wett the ceramic with similar thermal expansion coefficient to avoid large stresses at joints. In the present work we study mullite-molybdenum composites using a brazing alloy for the weldment.A scanning electron micrograph from the cross section of the joining sequence studied here is presented in Fig. 1.

Rheological characterization of tack and viscoelasticity of compositions of crepe coating used in the Yankee dryer

TAPPI Journal ◽  
2019 ◽  
Vol 18 (11) ◽  
pp. 641-649
Author(s):  
JOSHUA OMAMBALA ◽  
CARL MCINTYRE
Keyword(s):  
Normal Force ◽  
Weight Ratio ◽  
Good Combination ◽  
Rheological Characterization ◽  
Nonlinear Viscoelastic ◽  
Coating Composition ◽  
Linear And Nonlinear ◽  
Work Done ◽  
Tissue Production

The vast majority of tissue production uses creping to achieve the required set of properties on the base sheet. The Yankee coating helps to develop the desired crepe that in turn determines properties such as bulk and softness. The adhesion of the sheet to the Yankee surface is a very important characteristic to consider in achieving the desired crepe. The coating mix usually consists of the adhesive, modifier, and release. A good combination of these components is essential to achieving the desired properties of the tissue or towel, which often are determined by trials on the machine that can be time consuming and lead to costly rejects. In this paper, five compositions of an industrial Yankee coating adhesive, modifier, and release were examined rheologically. The weight ratio of the adhesive was kept constant at 30% in all five compositions and the modifier and release ratios were varied. The normal force and work done by the different compositions have been shown at various temperatures simulating that of the Yankee surface, and the oscillatory test was carried out to explain the linear and nonlinear viscoelastic characteristic of the optimal coating composition.

CHEMICAL AND RHEOLOGICAL CHARACTERIZATION OF A VEGETABLE-BASED EMULSION

2019 ◽  
Author(s):  
Luiz Eduardo Rodrigues Vieira ◽  
Leonardo Rosa Ribeiro da Silva ◽  
Felipe Chagas Rodrigues de Souza ◽  
Wisley Sales ◽  
Álisson Rocha Machado
Keyword(s):  
Rheological Characterization

RHEOLOGICAL CHARACTERIZATION OF PERUVIAN COPPER ORE SLURRIES

2020 ◽  
Author(s):  
Joel López Bonilla ◽  
Cesar Celis ◽  
Danmer Maza
Keyword(s):  
Rheological Characterization ◽  
Copper Ore

scholarly journals Toward Physicochemical and Rheological Characterization of Different Injectable Hyaluronic Acid Dermal Fillers Cross-Linked with Polyethylene Glycol Diglycidyl Ether

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 948
Author(s):  
Nicola Zerbinati ◽  
Sabrina Sommatis ◽  
Cristina Maccario ◽  
Maria Chiara Capillo ◽  
Giulia Grimaldi ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Polyethylene Glycol ◽  
Biological Activities ◽  
Diglycidyl Ether ◽  
Dermal Filler ◽  
Cross Linking ◽  
Matrix Structure ◽  
Dermal Fillers ◽  
Rheological Characterization

(1) Background: Injectable hyaluronic acid (HA) dermal fillers are used to restore volume, hydration and skin tone in aesthetic medicine. HA fillers differ from each other due to their cross-linking technologies, with the aim to increase mechanical and biological activities. One of the most recent and promising cross-linkers is polyethylene glycol diglycidyl ether (PEGDE), used by the company Matex Lab S.p.A., (Brindisi, Italy) to create the HA dermal filler PEGDE family. Over the last few years, several studies have been performed to investigate the biocompatibility and biodegradability of these formulations, but little information is available regarding their matrix structure, rheological and physicochemical properties related to their cross-linking technologies, the HA content or the degree of cross-linking. (2) Methods: Seven different injectable HA hydrogels were subjected to optical microscopic examination, cohesivity evaluation and rheological characterization in order to investigate their behavior. (3) Results: The analyzed cross-linked dermal fillers showed a fibrous “spiderweb-like” matrix structure, with each medical device presenting different and peculiar rheological features. Except for HA non cross-linked hydrogel 18 mg/mL, all showed an elastic and cohesive profile. (4) Conclusions: The comparative analysis with other literature works makes a preliminary characterization of these injectable medical devices possible.

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