Ultrasound-assisted of poly (trimethylene terephthalate) dyeing with nano-disperse blue 79: isotherms, kinetics, and thermodynamics insights

2020 ◽  
pp. 1-10
Author(s):  
Shirin Babaei Golshan Abadi ◽  
Mohammad Esmail Yazdanshenas ◽  
Ramin Khajavi ◽  
Abosaeed Rashidi ◽  
Mehdi Varsei
Keyword(s):  
Kinetics And Thermodynamics ◽  
Ultrasound Assisted ◽  
Trimethylene Terephthalate

scholarly journals Kinetics and Thermodynamics Study of Ultrasound-Assisted Depolymerization of k-Carrageenan in Acidic Solution

2020 ◽  
Vol 15 (1) ◽  
pp. 280-289
Author(s):  
Ratnawati Ratnawati ◽  
Nita Indriyani
Keyword(s):  
Molecular Weight ◽  
Rate Constant ◽  
Reaction Rate ◽  
Acidic Solution ◽  
Biomedical Application ◽  
Bond Cleavage ◽  
Reaction Rate Constant ◽  
Order Kinetic ◽  
Kinetics And Thermodynamics ◽  
Ultrasound Assisted

K-carrageenan is a natural polymer with high molecular weight ranging from 100 to 1000 kDa. The oligocarrageenan with low molecular weight is widely used in biomedical application. The aim of this work was to depolymerize k-carrageenan in an acidic solution with the assistance of ultrasound irradiation. The ultrasonication was conducted at various pH (3 and 6), temperatures (30-60 °C), and depolymerization time (0-24 minutes). The results show that the depolymerization reaction follows pseudo-first-order kinetic model with reaction rate constant of 1.856×10-7 to 2.138×10-6 s-1. The reaction rate constant increases at higher temperature and lower pH. The Q10-temperature coefficients of the depolymerization are 1.25 and 1.51 for pH 6 and 3, respectively. The enthalpy of activation (ΔH‡) and the Gibbs energy of activation (ΔG‡) are positive, while the entropy of activation (ΔS‡) is negative, indicating that the activation step of the ultrasound-assisted depolymerization of k-carrageenan is endothermic, non-spontaneous, and the molecules at the transition state is more ordered than at the ground state. The ΔH‡ and the ΔS‡ are not affected by temperature, while the ΔG‡ is a weak function of temperature. The ΔH‡ and ΔS‡ become smaller at higher pH, while the ΔG‡ increases with the increase of pH. The kinetics and thermodynamics analysis show that the ultrasound-assisted depolymerization of k-carrageenan in acidic solution is possibly through three mechanisms, i.e. bond cleavage due to cavitational effect of microbubbles, hydroxyl radical and hydrogen peroxide, as well as proton. Copyright © 2020 BCREC Group. All rights reserved 

Ultrasound assisted enzymolysis of sunflower meal protein: Kinetics and thermodynamics modeling

2018 ◽  
Vol 41 (7) ◽  
pp. e12865 ◽  
Author(s):  
Mokhtar Dabbour ◽  
Ronghai He ◽  
Benjamin Mintah ◽  
Yingxiu Tang ◽  
Haile Ma
Keyword(s):  
Sunflower Meal ◽  
Protein Kinetics ◽  
Kinetics And Thermodynamics ◽  
Meal Protein ◽  
Ultrasound Assisted ◽  
Thermodynamics Modeling

scholarly journals Kinetics and Thermodynamics of Ultrasound-Assisted Depolymerization of κ-Carrageenan

2016 ◽  
Vol 11 (1) ◽  
pp. 48 ◽  
Author(s):  
Ratnawati Ratnawati ◽  
Aji Prasetyaningrum ◽  
Dyah Hesti Wardhani
Keyword(s):  
Molecular Weight ◽  
Average Molecular Weight ◽  
Chain Scission ◽  
Number Average Molecular Weight ◽  
Covalent Bonds ◽  
Exponential Factor ◽  
Kinetics And Thermodynamics ◽  
Thermal Depolymerization ◽  
Ultrasound Assisted ◽  
Kinetics Of

<p>The ultrasound-assisted depolymerization of κ-carrageenan has been studied at various temperatures and times. The κ-carrageenan with initial molecular weight of 545 kDa was dispersed in water to form a 5 g/L solution, which was then depolymerized in an ultrasound device at various temperatures and times. The viscosity of the solution was measured using Brookfield viscometer, which was then used to find the number-average molecular weight by Mark-Houwink equation. To obtain the kinetics of κ-carrageenan depolymerization, the number-average molecular weight data was treated using midpoint-chain scission kinetics model. The pre-exponential factor and activation energies for the reaction are 2.683×10<sup>-7</sup> mol g<sup>-1</sup> min<sup>-1</sup> and 6.43 kJ mol<sup>-1</sup>, respectively. The limiting molecular weight varies from 160 kDa to 240 kDa, and it is linearly correlated to temperature. The results are compared to the result of thermal depolymerization by calculating the half life. It is revealed that ultrasound assisted depolymerization of κ-carrageenan is faster than thermal depolymerization at temperatures below 72.2°C. Compared to thermal depolymerization, the ultrasound-assisted process has lower values of E<sub>a</sub>, ΔG<sup>‡</sup>, ΔH<sup>‡</sup>, and ΔS<sup>‡</sup>, which can be attributed to the ultrasonically induced breakage of non-covalent bonds in κ-carrageenan molecules. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 10<sup>th</sup> November 2015; Revised: 18<sup>th</sup> January 2016; Accepted: 19<sup>th</sup> January 2016</em></p><p><strong>How to Cite</strong>: Ratnawati, R., Prasetyaningrum, A., Wardhani, D.H. (2016). Kinetics and Thermodynamics of Ultrasound-Assisted Depolymerization of κ-Carrageenan. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11(1): 48-58. (doi:10.9767/bcrec.11.1.415.48-58)</p><p><strong>Permalink/DOI</strong>:<a href="/index.php/bcrec/editor/viewMetadata/%20http:/dx.doi.org/10.9767/bcrec.11.1.415.48-58"> http://dx.doi.org/10.9767/bcrec.11.1.415.48-58</a></p><p> </p>

Innovative Extraction Techniques for the Optimum Extraction of Phenolic Compounds from Peanut Meal and Evaluation of Their Biological Activities

2019 ◽  
Vol 4 (2) ◽  
Keyword(s):  
Phenolic Compounds ◽  
Carcinoma Cell ◽  
Biological Activities ◽  
Peanut Meal ◽  
Ultrasound Assisted Extraction ◽  
Carcinoma Cell Lines ◽  
Assisted Extraction ◽  
Phenolic Extract ◽  
Ultrasound Assisted ◽  
Water Ratio

There is a worldwide demand for phenolic compounds (PC) because they exhibit several biological activities. This work aimed at extracting phenolic compounds from peanut meal. The methods of extraction were mainly: conventional solvent extraction (traditional methods) and ultrasound assisted extraction (recent methods) and comparing their results. Peanut meal (PM) was prepared by defatting with n-hexane, and then extracted by the two previous methods. First, the conventional solvents used were 80% methanol, ethanol, acetone, isopropanol, and distilled water. Then studied Different parameters such as meal: water ratio, also the effect of temperature and the pH on the extraction process. Second, ultrasonic assisted extractions (USAE), the parameters investigated were temperature, time and speed of sonication. Finally, all the extracts were analyzed by HPLC for their phenolic contents. Results indicated that the highest extracted PC achieved by solvents was in distilled water where 1:100, Meal: Water ratio which extracted 40 mg PC / g PM at 30& 35°C. Highest extracted PC was achieved by alkaline medium at pH 12 more than acidic and neutral medium. While (USAE) at speed 8 ultrasonication and temperature 30ᵒC, extracted 49.2mg PC /g PM. Sothe ultrasound assisted extraction exhibited great influence on the extraction of phenolic compounds from peanut meal. The ultrasonic peanut extract was examined for its antioxidant, antimicrobial and anticarcinogenic activities. The antioxidant activity of PM phenolic extract prepared by ultrasonic technique, was measured by, β-carotene, and DPPH methods, and reducing antioxidant power. Results revealed values: 84.57, 57.72 and 5960 respectively. The PM extract showed different levels of antimicrobial activity against the pathogenic bacteria used. As for the anticarcinogenic effect PM phenolic extract most effective on inhibiting colon carcinoma and lung carcinoma cell lines with IC50 = 20.7 and 20.8 µ/ml., respectively. This was followed by intestinal carcinoma and liver carcinoma cell lines with IC50= 39.6 and 40.2µ/ml.

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