Comparative Studies of the Synthesis and Physical Characterization of ZnO Nanoparticles Using Nerium oleander Flower Extract and Chemical Methods

Khalil, M.; Alqahtany, Faleh Z.

doi:10.1007/s10904-020-01494-w

Cited by 13 publications

(9 citation statements)

References 61 publications

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“…A chemical method was also used to synthesize ZnO NPs according the method described by Khalil and Alqahtany (2020) . Briefly, 50 mL (0.2 mol/L) C 4 H 6 O 4 Zn•2H 2 O solution and 50 mL 0.2 mol/L NaBH 4 solution were agitated for 1 h, and then settled overnight.…”

Section: Methodsmentioning

confidence: 99%

Zinc oxide nanoparticles synthesized using coffee leaf extract assisted with ultrasound as nanocarriers for mangiferin

Wang

Mei

Manivel

et al. 2022

Current Research in Food Science

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Section: Methodsmentioning

confidence: 99%

Zinc oxide nanoparticles synthesized using coffee leaf extract assisted with ultrasound as nanocarriers for mangiferin

Wang

Mei

Manivel

et al. 2022

Current Research in Food Science

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“…Activation energy ( E a ) for the main stage of decomposition was calculated on the basis of TGA analysis and Arrhenius kinetic theory. It was calculated from the slope of the plot of ln [ln(1/ y )] versus 1000/ T , , which yielded a straight line based on Broido’s equation, as given in eq ln [ ln true( 1 y true) ] = prefix− ( E a RT ) + ln nobreak0em.25em⁡ A where E a is the activation energy (kJ/mol), R is the universal gas constant ( R = 8.314 J·mol –1 ·K –1 ), T is the temperature recorded in thermogram (K), and A is the pre-exponential factor (min –1 ). The conversion degree, which is denoted by y , was calculated using eq y = w normalt − w ∞ w 0 − w ∞ where w t is the weight that has not yet decomposed, w o is the original weight, and w ∞ is the residue weight.…”

Section: Methodsmentioning

confidence: 99%

Section: Thermal Stability Analysismentioning

confidence: 99%

Mechanical and Thermal Evaluation of Carrageenan/Hydroxypropyl Methyl Cellulose Biocomposite Incorporated with Modified Starch Corroborated by Molecular Interaction Recognition

Ramli

Adam

Amin

et al. 2022

ACS Appl. Polym. Mater.

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Vegetarian hard capsule has attracted surging demand as an alternative to gelatin; however, only few have been commercialized. Carrageenan extracted from seaweed has the potential to be utilized as a hard capsule material. Improving the mechanical and thermal properties of carrageenan biocomposite is therefore of great importance for future use in the drug delivery system. Hence, carboxymethyl sago starch (CMSS) was incorporated to strengthen the carrageenan biocomposite in a concentration range from 0 to 1.0% w/v. The intermolecular hydrogen bonding formed between carrageenan and CMSS was revealed via density functional theory (DFT) calculations and substantiated by 1 H NMR and FTIR spectra. The result showed that the hydrogen bond is established between hydroxyl (carrageenan)−carbonyl (CMSS) groups at a distance of 1.87 Å. The bond formation subsequently increased the tensile strength of the biocomposite film and the loop strength of the hard capsule by 20.6 and 7.7%, respectively. The glass transition temperature of the film was increased from 37.8 to 47.8 °C, increasing the thermal stability. The activation energy upon decomposition of the film is 74.4 kJ•mol −1 , representing a 26.2% increase over the control carrageenan. These findings demonstrate that incorporation of CMSS increases the properties of carrageenan biocomposite and provides a promising alternative to animal-based hard capsules.

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“…where y is the degree of conversion, w t is the weight at any time in grams, w o is the initial weight, and w ∞ is the weight of residue. Based on the degree of conversion, a graph was drawn by plotting ln [ln (1/y)] versus 1000/T, where the value of E a was provided from the slope of the graph [31,32] as in Equation ( 2):…”

Section: Kinetic Analysis By Broido's Modelmentioning

confidence: 99%

“…[70,73] The positive values of ΔG reveal that the thermal degradation of all films is a non-spontaneous process (ΔG > 0, endergonic) and is difficult to carry out at the end of the process, which subsequently increases the thermal stability of the film. [31] 4 | CONCLUSION Introducing HPMC in the carrageenan matrix plays a vital role that significantly influences the mechanical and thermal behaviour of the film. Carra-HPMC0.8 film demonstrated comparable yet promising mechanical properties in terms of tensile strength, elongation at break, and capsule loop strength, confirming the positive effect of HPMC.…”

Section: Kinetic Analysis By the Broido's Modelmentioning

confidence: 99%

Evaluation of mechanical and thermal properties of carrageenan/hydroxypropyl methyl cellulose hard capsule

et al. 2022

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The inherent source of gelatin used for commercial hard capsules causes a surging demand for vegetarian capsules. In this work, carrageenan is utilized in preparing hard capsules to meet consumer preferences. Hydroxypropyl methylcellulose (HPMC) was incorporated as a reinforcing agent to improve the low mechanical properties of hard capsules made of carrageenan. The HPMC concentration was manipulated from 0.2 to 1.0 w/v% in the carrageenan matrix. The increasing concentration of HPMC exerts significant effects on the tensile strength and elongation at break, with an improvement of 59.1% and 46.9%, respectively, at the optimized HPMC concentration of 0.8 w/v%. The loop strength of the capsule is also increased by 56.4% with decreasing moisture content. The downfield movement from around 3.20 ppm of the carrageenan proton to 3.33 ppm in the proton nuclear magnetic resonanance ( 1H‐NMR) spectrum suggests the formation of intermolecular hydrogen bonding between carrageenan and HPMC, which correlates to the results of Fourier‐transform infrared spectroscopy (FTIR) and zeta potential. The glass transition temperature of the film was increased from 37.8 to 65.3°C, showing an upgrade in thermal stability. The film possesses a major mass loss with an activation energy of 64.7 kJ/mol with an increment of 43.4% compared to the control carrageenan. These findings support the conclusion that HPMC enhanced the mechanical properties and thermal stability of the carrageenan film, and the comprehensive analysis of the molecular interaction and decomposition kinetics subsequently may expand the application fields of the carrageenan‐HPMC hard capsule as an alternative to gelatin in the future.

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Comparative Studies of the Synthesis and Physical Characterization of ZnO Nanoparticles Using Nerium oleander Flower Extract and Chemical Methods

Cited by 13 publications

References 61 publications

Zinc oxide nanoparticles synthesized using coffee leaf extract assisted with ultrasound as nanocarriers for mangiferin

Zinc oxide nanoparticles synthesized using coffee leaf extract assisted with ultrasound as nanocarriers for mangiferin

Mechanical and Thermal Evaluation of Carrageenan/Hydroxypropyl Methyl Cellulose Biocomposite Incorporated with Modified Starch Corroborated by Molecular Interaction Recognition

Evaluation of mechanical and thermal properties of carrageenan/hydroxypropyl methyl cellulose hard capsule

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