Physical and Thermal Properties of Chitosan

Siriprom, Wichian; Chantarasunthon, K.; Teanchai, K.

doi:10.4028/www.scientific.net/amr.979.315

Cited by 4 publications

(3 citation statements)

References 4 publications

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“…The bulk‐specific heat linear regression equations for C1 and RC are shared as following:

C_{p, C 1} = 5.42 M_{% (italicwb)} + 1.85 (r^{2} = 0.9998),

C_{p, RC} = 5.40 M_{% (italicwb)} + 1.78 (r^{2} = 0.9997) .

Even though the bulk thermal conductivity values were low when compared to different agricultural products (Doymaz & Pala, 2003; Siriprom et al, 2014; Sreenarayanan & Chattopadhyay, 1986), both evaluated varieties presented higher bulk thermal conductivity values than the Caturra mutation and other varieties (Chandrasekar & Viswanathan, 1999; Ghosh & Gacanja, 1970; Pérez‐Alegría et al, 2001), implying that they are able to transfer heat faster than other ones (Figure 9). Suppose this property is combined with the fact that they also displayed higher C p values, then, for such varieties, the heat will travel faster across the grain bed thanks to the bulk thermal conductivity and will also remain for a more extended time due to the C p .…”

Section: Resultsmentioning

confidence: 99%

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Thermophysical properties of parchment coffee: New Colombian varieties

Duque‐Dussán

Sanz‐Uribe²,

Lubert

et al. 2023

J Food Process Engineering

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The thermophysical properties of coffee have a special partaking during the drying process since a material‐depending heat and mass transfer occurs between the bean and the drying air. Conditional to the thermophysical properties of the parchment coffee, the drying can be more or less efficient, affecting the final quality and seed safety. Several coffee varieties have been studied; however, the National Coffee Research Center of Colombia has developed new highly productive coffee varieties resistant to different diseases: Cenicafé 1 and Castillo®. Nevertheless, the thermophysical properties of these specific varieties were not yet investigated; moreover, the availability of information related to these properties of different coffee varieties in the literature is relatively scarce. Thus, this study targeted to determine the parchment coffee thermophysical properties of these new varieties at five different moisture contents % (wb): 53%, 42%, 32%, 22% and 11%, using optimized techniques and methods to ensure high accuracy and exactness. It was found that the new varieties have larger, heavier, and denser beans; it was also seen that the bulk thermal conductivity and the bulk‐specific heat are higher in these varieties than in the older ones. It was also revealed that the length, width, thickness, and surface area did not change as the moisture was removed, whereas the bulk density, kernel density, mass, bulk‐specific heat, and bulk thermal conductivity decreased as the moisture was reduced. Displaying better thermophysical properties will improve the drying and roasting processes; hence, a better final product can be expected from these varieties. Practical applications Knowing the thermal and physical properties of these new varieties will allow the growers and coffee processing facilities to predict, simulate and control different post‐harvesting processes such as pulping, fermentation, drying, storing, and roasting. Also, the already developed mathematical models to estimate coffee drying times can be updated, improving the accuracy of the predictions, bed porosities, mass, and heat transfer in order to safeguard the innocuousness of the product.

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“…The bulk‐specific heat linear regression equations for C1 and RC are shared as following:

C_{p, C 1} = 5.42 M_{% (italicwb)} + 1.85 (r^{2} = 0.9998),

C_{p, RC} = 5.40 M_{% (italicwb)} + 1.78 (r^{2} = 0.9997) .

Section: Resultsmentioning

confidence: 99%

“…To determine the bulk‐specific heat capacity of the coffee ( C pcoffee ), the method of mixtures (Monirul Islam Chowdhury et al, 2001; Siriprom et al, 2014) was used. A 100 g sample of coffee was heated indirectly in a water bath; a thermocouple temperature sensor controlled the grain temperature.…”

Section: Methodsmentioning

confidence: 99%

Thermophysical properties of parchment coffee: New Colombian varieties

Duque‐Dussán

Sanz‐Uribe²,

Lubert

et al. 2023

J Food Process Engineering

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“…These two phases correspond to the hydrated crystallization and anhydrous crystallization of chitosan, respectively. The development of crystallinity in chitosan was due to the formation of hydrogen bonds between chains, and the crystalline form of chitosan changes with the conformation of chitosan [30]. The diffraction pattern of SiO2 shows no polycrystalline peak except of the broad one centered at 2θ = 23°, indicating that the SiO2 has an amorphous-crystalline structure.…”

Section: X-ray Diffraction Analysismentioning

confidence: 99%

Chitosan/Silica Nanocomposite Preparation from Shrimp Shell and Its Adsorption Performance for Methylene Blue

et al. 2022

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In this study, novel chitosan/silica composites with different mass ratios were prepared by in-situ hydrolysis using chitosan (from shrimp shell) as a carrier, triblock copolymer (P123) as the structure-directing agent, and ethyl orthosilicate as a silicon source. These nanocomposites were characterized by different techniques, including the FT-IR, XRD, TGA, SEM, TEM and N2 adsorption–desorption. The results indicated that the morphology and properties of composites changed with the introduction of silica. When the CS/TEOS mass ratio was 0.0775, the CS−2/SiO2 composite displayed a coral-like three-dimensional porous structure with specific surface area of 640.37 m2/g and average pore size of 1.869 nm. The adsorption properties for methylene blue (MB) were investigated as well and the CS−2/SiO2 showed better adsorption performance. The removal rate for MB reached 94.01% with absorbents dosage of 6 g/L, initial concentration of 40 mg/L, initial pH value of 7, temperature of 35 °C, and adsorption time of 40 min. The adsorption process well fitted the Langmuir isothermal model and quasi-second-order adsorption kinetics model. The maximum adsorption capacity for MB was 13.966 mg/g based on Langmuir fitting. The surface functional groups of the composites can play an important role in the adsorption. The adsorption mechanism of CS−2/SiO2 on MB involved electrostatic interaction, hydrogen bonding and functional group complexation. In addition, the prepared chitosan/silica composites showed good reusability at six cycles, making them a promising material in the application of removing dyeing wastewater.

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