scholarly journals Rheological Characterization of Agarose and Poloxamer 407 (P407) Based Hydrogels

MRS Advances ◽  
2018 ◽  
Vol 3 (30) ◽  
pp. 1719-1724 ◽  
Author(s):  
Nehir Kandemir ◽  
Yuqing Xia ◽  
Pengfei Duan ◽  
Wenjian Yang ◽  
Jinju Chen
Keyword(s):  
Loss Modulus ◽  
Thermomechanical Properties ◽  
Poloxamer 407 ◽  
Strain Rates ◽  
Rheological Characterization ◽  
Order Of Magnitude ◽  
Softening Material ◽  
Composite Moduli ◽  
The Given

ABSTRACTPoloxamer 407 (P407) is a biocompatible thermo-setting polymer, while agarose is a biocompatible thermo-softening material. It is interesting to mix them to examine any possible synergy in thermomechanical properties. In this study, rotational rheometer was adopted to study rheological properties of the mixtures of agarose/P407 gels with different concentrations at various frequencies, strain rates and temperatures. It has revealed that the addition of P407 decreased the gel stiffness by an order of magnitude. For the given combinations in this study, the increase in agarose concentration would increase both the storage modulus and loss modulus of the gel mixtures. The variation in P407 concentration (2.5%-10%) minimally changes the composite moduli. These agarose/P407 gel mixtures also exhibited shear thinning behavior. However, the addition of P407 (2.5%-10%) to agarose gel only has very small effect on thermomechanical properties of agarose gels. The overall transition temperature for these gel mixtures is governed by P407 melting point where the phase change starts around 55°C and the gels completely collapse at the melting temperature of agarose.

Rheological characterization of Poloxamer 407 lidocaine hydrochloride gels

2002 ◽  
Vol 17 (3) ◽  
pp. 161-167 ◽  
Author(s):  
E.J Ricci ◽  
M.V.L.B Bentley ◽  
M Farah ◽  
R.E.S Bretas ◽  
J.M Marchetti
Keyword(s):  
Poloxamer 407 ◽  
Lidocaine Hydrochloride ◽  
Rheological Characterization

Rheological characterization of biocompatible associative polymer hydrogels with crystalline and amorphous endblocks

2006 ◽  
Vol 21 (8) ◽  
pp. 2118-2125 ◽  
Author(s):  
Sarvesh K. Agrawal ◽  
Naomi Sanabria-DeLong ◽  
Gregory N. Tew ◽  
Surita R. Bhatia
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Elastic Modulus ◽  
Block Length ◽  
Rheological Characterization ◽  
Precise Control ◽  
Order Of Magnitude ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Control over mechanical properties of hydrogels is of primary importance for the use of these materials in drug delivery and tissue engineering applications. We demonstrate here that crystallinity and block length of poly(lactide) (PLA) can be used to tune the elastic modulus of associative network gels of poly(lactide)–poly(ethylene oxide)–poly(lactide) over several orders of magnitude. Polymers made with crystalline L lactic acid blocks formed very stiff hydrogels at 25 wt% concentration with an elastic modulus that was almost an order of magnitude higher than hydrogels of polymers with a similar molecular weight but containing amorphous D/L-lactic acid blocks. The relaxation behavior and crosslink density of gels are also significantly influenced by crystallinity of PLA and are again a function of PLA block length. Using these variables we can design new tailor-made materials for biomedical applications with precise control over their structure and mechanical properties.

scholarly journals Rheological Characterization of Commercial Sweetened Condensed Milk

2014 ◽  
Vol 32 (1) ◽  
Author(s):  
AFONSO MOTA RAMOS ◽  
ANDERSON NASCIMENTO DE OLIVEIRA ◽  
MANOELA MACIEL S. DIAS ◽  
ERICK ORNELLAS NEVES
Keyword(s):  
Loss Modulus ◽  
Material Behavior ◽  
Effect Of Temperature ◽  
Rheological Characterization ◽  
Sweetened Condensed Milk ◽  
Pseudoplastic Fluid ◽  
Fluid Behavior ◽  
Condensed Milk ◽  
Versus Strain

The present study have analyzed samples of sweetened condensed milk of five brands sold in the Brazilian market regarding their rheological behavior and viscoelasticity. The products presented pseudoplastic fluid behavior, illustrated by the experimental data of shear stress versus strain rate, with adjustments made to fit the Power Law and Casson models. The effect of temperature on apparent viscosity of the products followed the Arrhenius model, with activation energy values ranging from 33.8 to 40.9 kJ mol-1. The products showed loss modulus (G’’) greater than storage modulus (G ‘), indicating a semi-liquid material behavior.

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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