ABSTRACT
This research aims to create an emulsion formulation utilizing lignin as a carrier and citronella oil for its application as a herbicide. The formulation composition includes lignin solution 55-62%v/v, Tween 80 25%w/v, propylene glycol 10%w/v, and citronella oil 3-10%w/v. The preparation steps involve preparing the oil phase by mixing tween 80 surfactant, propylene glycol, and citronella oil; preparing the aqueous phase by mixing lignin into distilled water at pH 12 with stirring; mixing the oil phase and the water phase accompanied by stirring at 5000-10000 rpm for 1-5 minutes until a stable solution is formed as a natural herbicide. The application outcomes revealed that the formulation successfully eliminated specific weeds within two to three days at the maximum concentration of 10%, leaving no detectable herbicide residue after 7 and 15 days of treatment. The result demonstrates how green technology has the capacity to replace herbicides derived from chemicals, especially in the agricultural sector.
ABSTRACT
Thermoplastic starch (TPS) is considered as alternative material for substitute petroleum-based materials for single-use packaging material applications. The main weakness of TPS is sensitive to water and humidity which causes low mechanical properties and low thermal resistance. To address this limitation, one can enhance the strength is by incorporating cellulose nanofiber as a reinforcing agent. Cellulose nanofiber used in this study is bacterial cellulose, synthesized from tapioca liquid waste media, namely Nata de Cassava (NDCass). The effect of NDCass addition to TPS on chemical characteristics, physical properties, crystallinity, mechanical properties, and thermal properties was investigated. As the results, NDCass incorporation has no significant effect on the chemical structure and crystal structure of composites as observed by FTIR and XRD analysis. Incorporating of NDCass improved the mechanical properties by 37.3 %, the thermal stability, and the viscosity, however reduced the elongation at break by 65.6 %, the density, the melt flow and shear rate of TPS biocomposite. This study evidently that starch from Arenga pinnata trunk and bacterial cellulose from tapioca liquid waste can be manufactured into biocomposites using in-situ twin screw extrusion which beneficial for large-scale applications.
Subject(s)
Cellulose , Nanofibers , Cellulose/chemistry , Starch/chemistry , Nanofibers/chemistry , Water/chemistryABSTRACT
The spreading behavior of a coating solution is an important factor in determining the effectiveness of spraying applications. It determines how evenly the droplets spread on the substrate surface and how quickly they form a uniform film. Fluid mechanics principles govern it, including surface tension, viscosity, and the interaction between the liquid and the solid surface. In our previous work, chitosan (CS) film properties were successfully modified by blending with polyvinyl alcohol (PVA). It was shown that the mechanical strength of the composite film was significantly improved compared to the virgin CS. Here we propose to study the spreading behavior of CS/PVA solution on fresh bananas. The events upon droplet impact were captured using a high-speed camera, allowing the identification of outcomes as a function of velocity at different surface wettabilities (wetting and non-wetting) on the banana peels. The mathematical model to predict the maximum spreading factor, ßmax, was governed by scaling law analysis using fitting experimental data to identify patterns, trends, and relationships between ßmax and the independent variables, Weber (We) numbers, and Reynolds (Re) numbers. The results indicate that liquid viscosity and surface properties affect the droplet's impact and spreading behavior. The Ohnesorge (Oh) numbers significantly influenced the spreading dynamics, while the banana's surface wettability minimally influenced spreading. The prediction model reasonably agrees with all the data in the literature since the R2 = 0.958 is a powerful goodness-of-fit indicator for predicting the spreading factor. It scaled with ßmax=a+0.04We.Re1/3, where the "a" constants depend on Oh numbers.
ABSTRACT
The premise of this work is the modification of the properties of chitosan-based film for possible use in food packaging applications. The biofilm was prepared via thermal and mechanical treatment through blending polymers with chitosan using Polyvinyl Alcohol (PVA) and loading different types of chemical agents, i.e., citric acid (CA), succinic acid (SA), and tetraethoxysilane (TEOS). The modification was carried out under high-speed homogenization at elevated temperature to induce physical cross-linkage of chitosan polymer chains without a catalyst. The findings showed that PVA improved the chitosan films' Tensile strength (TS) and elongation at break (Eb). The presence of chemicals caused an increase in the film strength for all samples prepared, in which a 5% w/w of chemical in the optimum composition CS/PVA (75/25) provided the maximum strength, namely, 33.9 MPa, 44.0 MPa, and 41.9 MPa, for CA-5, SA-5, and TEOS-5, respectively. The chemical agents also increased the water contact angles for all tested films, indicating that they promoted hydrophobicity. The chemical structure analysis showed that, by incorporating three types of chemical agents into the CS/PVA blend films, no additional spectral bands were found, indicating that no covalent bonds were formed. The thermal properties showed enhancement in melting peak and degradation temperature of the blend films, compared to those without chemical agents at the optimum composition. The X-ray diffraction patterns exhibited that PVA led to an increasing crystallization tendency in the blend films. The morphological observation proved that no irregularities were detected in CS/PVA blend films, representing high compatibility with both polymers.
ABSTRACT
Thermoplastic starch (TPS) has three main disadvantages, i.e., poor mechanical properties, low thermal stability and water sensibility. To overcome these disadvantages, TPS properties can be improved by starch modification, adding reinforcements and blending with other polymers. In this research, to prepare modified TPS, starch modification was carried out by in situ modification. The modified TPS was prepared by adding Arenga pinnata palm starch (APPS), glycerol and benzoyl peroxide simultaneously in the twin-screw extruder. Morphology analysis of TPS revealed that the starch granules were damaged and gelatinized in the extrusion process. No phase separation is observed in TPS, which exhibits that starch granules with and without benzoyl peroxide were uniformly dispersed in the matrix. The addition of benzoyl peroxide resulted in increased density of TPS from 1.37 to 1.39 g·cm-3, tensile strength from 7.19 to 8.61 MPa and viscosity from 2482.19 to 2604.60 Pa.s. However, it decreased the elongation at break of TPS from 33.95 to 30.16%, melt flow rate from 7.13 to 5.73 gr/10 min and glass transition temperature from 65 to 52 °C. In addition, the thermal analysis showed that the addition of benzoyl peroxide increased the thermal stability of TPS and extended the temperature range of thermal degradation.
ABSTRACT
The method of solvothermal by one-step operation has been performed to synthesize of magnetic amine-functionalized sugarcane bagasse biocomposites (SB-MH). The obtained SB-MH contains 62.34% of Fe, 17.8 mmol/g of amine, and a magnetic property of 19.46 emu/g. The biocomposite surface area increased significantly from 1.617 to 25.789 m2/g after amine functionalization. The optimum condition of SB-MH used for Pb(II) ion removal was achieved at pH 5 for 360 min with adsorption capacity of 203.522 mg/g. The pseudo 2nd order was well-fitted to the model of Pb(II) ion adsorption. Meanwhile, other contaminant parameters number of Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), and dye in wastewater were also remarkably reduced by about 74.4%, 88.0%, and 96.7%, respectively. The reusability of SB-MH with 4th repetitions showed only a slight decrease in performance of 5%. Therefore, the proposed magnetic amine-functionalized sugarcane bagasse biocomposites lead to a very potential adsorbent implemented in high scale due to high surface area, easy separation, stable materials and capability to adsorb contaminants from aqueous solution.
