Starch-Chitosan Hydrogels for the Controlled-Release of Herbicide in Agricultural Applications: A Study on the Effect of the Concentration of Raw Materials and Crosslinkers

2022 ◽  
Author(s):  
Karishma Supare ◽  
Prakash Mahanwar
Keyword(s):  
Controlled Release ◽  
Raw Materials ◽  
Agricultural Applications ◽  
Chitosan Hydrogels

Characterization and Physical Properties of Chitosan Modified Bamboo Pulp Fiber Fabric

2011 ◽  
Vol 197-198 ◽  
pp. 1231-1235 ◽  
Author(s):  
Xin Liu ◽  
Yun Hui Xu ◽  
Wei Wei Zhang
Keyword(s):  
Controlled Release ◽  
Sodium Periodate ◽  
Raw Materials ◽  
Covalent Bond ◽  
Added Value ◽  
Aqueous Acetic Acid ◽  
Pulp Fiber ◽  
Bamboo Pulp ◽  
Recovery Angle ◽  
Fiber Fabric

With science and standard of living progressing, functional textile become more and more popular. We reported that a new bamboo pulp fiber fabric with the chitosan modification (CMBPFF) was prepared by the selective oxidation of sodium periodate and then treatment with a solution of chitosan aqueous acetic acid. The resulting CMBPFF is a nonpolluting and eco-friendly fabric product through the method of natural raw materials and no additives, which not only increase the added value of the product but also achieve natural ecological fabrics. This research using Kjeldahl nitrogen analysis showed that the maximum percentage of chitosan crosslinked on bamboo pulp fiber fabric was 10.52% (w/w). FT-IR spectra characterization suggested that the imine covalent bond between the chitosan and the oxidized bamboo pulp cellulose was formed through a series of reaction. The breaking strength of the modified fabric remained basically unchanged when the concentration of sodium periodate was less than 2.0 mg/ml. Furthermore, the chitosan modified bamboo pulp fiber fabric had the good antibacterial property. The wrinkle recovery angle and moisture regain of the chitosan modified fabric were improved. Meanwhile, a model experiment for the controlled release the drug was investigated using cactus extracts, a component of a Chinese medicine, indicated the extensive applicability of CMBPFF as a carrier for the controlled release drugs.

scholarly journals Lauric Acid-Modified Nitraria Seed Meal Composite as Green Carrier Material for Pesticide Controlled Release

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Bo Bai ◽  
Xiaohui Xu ◽  
Jingjie Hai ◽  
Na Hu ◽  
Honglun Wang ◽  
...  
Keyword(s):  
Controlled Release ◽  
Lauric Acid ◽  
Hydrophobic Surface ◽  
Seed Meal ◽  
Hydrophobic Property ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Agricultural Applications ◽  
Highly Hydrophobic ◽  
Efficient Loading

To alleviate the adverse effects of pesticide residues on the environment, development of a more safe, economical, and reliable usage approach of pesticides is critically urgent. In the present study, a novel pesticide carrier LA-NSM (lauric acid-modified Nitraria seed meal) with controlled release property was prepared through grafting esterification of lauric acid onto Nitraria seed meal substrates. The structure of the obtained samples was characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and contact angle measurements. The results indicated that LA-NSM products had a well-defined hydrophobic surface and irregular holes for efficient loading of pesticide molecules. Deltamethrin (DEL), a representative insoluble pyrethroid insecticide in water, was deliberately selected as the index pesticide to evaluate the loading and releasing efficiency of LA-NSM. The loading capacity of LA-NSM for DEL can reach about 1068 mg/g. pH, humidity of soil, and temperature had a significant influence on controlled release performance of LA-NSM@DEL. Moreover, the releasing kinetics of LA-NSM@DEL composites could be fitted well with the Higuchi model. Overall, the highly hydrophobic property, excellent loading, and controlled release ability of LA-NSM made it a promising candidate in agricultural applications.

scholarly journals Evaluation of Pig Manure for Environmental or Agricultural Applications through Gasification and Soil Leaching Experiments

2021 ◽  
Vol 11 (24) ◽  
pp. 12011
Author(s):  
Despina Vamvuka ◽  
Adamantia Raftogianni
Keyword(s):  
Carbon Dioxide ◽  
Soil Amendment ◽  
Activated Carbons ◽  
Raw Materials ◽  
Structural Characteristics ◽  
Pig Manure ◽  
Mineral Matter ◽  
Soil Leaching ◽  
Agricultural Applications ◽  
Leaching Experiments

The current study aimed at evaluating an untreated pig manure, firstly for its suitability for soil amendment in combination with an agricultural/bio-solid biochar, and secondly for its potential to be used for adsorption of hazardous species, replacing expensive activated carbons. Column soil leaching experiments were designed to simulate field conditions, and physical, chemical and mineralogical analyses were performed for raw materials and/or leachates. For activated carbon production, the manure was gasified by steam or carbon dioxide at high temperatures. Biochars were analyzed for organic and mineral matter, structural characteristics and organic functional groups. Activation by steam or carbon dioxide greatly enhanced specific surface area, reaching values of 231.4 and 233.3 m2/g, respectively. Application of manure to the soil promoted leaching of nitrates and phosphates and raised COD values of water extracts. Biochar addition retained these ions and reduced COD values up to 10 times at the end of the three-month period. The concentrations of heavy metals in the leachates were low and, in the presence of biochar in soil blends, they were significantly reduced by 50–70%. The manure presents a significant potential for adsorption of various pollutants or improvement of soil amendment if carefully managed.

scholarly journals Layered double hydroxide/sepiolite hybrid nanoarchitectures for the controlled release of herbicides

2019 ◽  
Vol 10 ◽  
pp. 1679-1690 ◽  
Author(s):  
Ediana Paula Rebitski ◽  
Margarita Darder ◽  
Pilar Aranda
Keyword(s):  
Controlled Release ◽  
Ion Exchange ◽  
Single Step ◽  
Basal Spacing ◽  
In Vitro Tests ◽  
Bidistilled Water ◽  
Continuous Release ◽  
Agricultural Applications ◽  
Double Hydroxides

In this work, organic–inorganic hybrid nanoarchitectures were prepared in a single coprecipitation step by assembling magnesium–aluminum layered double hydroxides (MgAl-LDH) and a sepiolite fibrous clay, with the simultaneous encapsulation of the herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) as the MgAl-LDH retains its ion exchange properties. The synthetic procedure was advantageous in comparison to the incorporation of MCPA by ion exchange after the formation of the LDH/sepiolite nanoarchitecture in a previous step, as it was less time consuming and gave rise to a higher loading of MCPA. The resulting MCPA-LDH/sepiolite nanoarchitectures were characterized by various physicochemical techniques (XRD, FTIR and 29Si NMR spectroscopies, CHN analysis and SEM) that revealed interactions of LDH with the sepiolite fibers through the silanol groups present on the outer surface of sepiolite, together with the intercalation of MCPA in the LDH confirmed by the increase in the basal spacing from 0.77 nm for the pristine LDH to 2.32 nm for the prepared materials. The amount of herbicide incorporated in the hybrid nanoarchitectures prepared by the single-step coprecipitation method surpassed the CEC of LDH (ca. 330 mEq/100 g), with values reaching 445 mEq/100 g LDH for certain compositions. This suggests a synergy between the inorganic solids that allows the nanoarchitecture to exhibit better adsorption properties than the separate components. Additionally, in the release assays, the herbicide incorporated in the hybrid nanoarchitectures could be completely released, which confirms its suitability for agricultural applications. In order to achieve a more controlled release of the herbicide and to act for several days on the surface of the soil, the hybrid nanoarchitectures were encapsulated in a biopolymer matrix of alginate/zein and shaped into spheres. In in vitro tests carried out in bidistilled water, a continuous release of MCPA from the bionanocomposite beads was achieved for more than a week, while the non-encapsulated materials released the 100% of MCPA in 48 h. Besides, the encapsulation may allow for better handling and transport of the herbicide.

scholarly journals Chitosan Hydrogels for Chondroitin Sulphate Controlled Release: An Analytical Characterization

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Annalisa Bianchera ◽  
Enrico Salomi ◽  
Matteo Pezzanera ◽  
Elisabeth Ruwet ◽  
Ruggero Bettini ◽  
...  
Keyword(s):  
Controlled Release ◽  
Chondroitin Sulphate ◽  
Sem Analysis ◽  
Uv Spectrophotometry ◽  
Analytical Characterization ◽  
Feret Diameter ◽  
Chitosan Scaffolds ◽  
Chitosan Hydrogels

This paper provides an analytical characterization of chitosan scaffolds obtained by freeze-gelation toward the uptake and the controlled release of chondroitin sulphate (CS), as cartilage repair agent, under different pH conditions. Scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and liquid chromatography-UV spectrophotometry (LC-UV) techniques were exploited to obtain qualitative and quantitative descriptions of polymer and drug behaviour in the biomaterial. As for morphology, SEM analysis allowed the evaluation of scaffold porosity in terms of pore size and distribution both at the surface (Feret diameter58±19 μm) and on the cross section (Feret diameter106±51 μm). LC and ATR-FTIR evidenced a pH-dependent CS loading and release behaviour, strongly highlighting the role of electrostatic forces on chitosan/chondroitin sulphate interactions.

scholarly journals Applied Rheology as Tool for the Assessment of Chitosan Hydrogels for Regenerative Medicine

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2189
Author(s):  
Pablo Sánchez-Cid ◽  
Mercedes Jiménez-Rosado ◽  
María Alonso-González ◽  
Alberto Romero ◽  
Victor Perez-Puyana
Keyword(s):  
Mechanical Properties ◽  
Regenerative Medicine ◽  
Significant Influence ◽  
Soft Tissues ◽  
Raw Materials ◽  
Gelation Temperature ◽  
Key Factor ◽  
High Thermal Resistance ◽  
Chitosan Hydrogels ◽  
Agitation Time

The regeneration of soft tissues that connect, support or surround other tissues is of great interest. In this sense, hydrogels have great potential as scaffolds for their regeneration. Among the different raw materials, chitosan stands out for being highly biocompatible, which, together with its biodegradability and structure, makes it a great alternative for the manufacture of hydrogels. Therefore, the aim of this work was to develop and characterize chitosan hydrogels. To this end, the most important parameters of their processing, i.e., agitation time, pH, gelation temperature and concentration of the biopolymer used were rheologically evaluated. The results show that the agitation time does not have a significant influence on hydrogels, whereas a change in pH (from 3.2 to 7) is a key factor for their formation. Furthermore, a low gelation temperature (4 °C) favors the formation of the hydrogel, showing better mechanical properties. Finally, there is a percentage of biopolymer saturation, from which the properties of the hydrogels are not further improved (1.5 wt.%). This work addresses the development of hydrogels with high thermal resistance, which allows their use as scaffolds without damaging their mechanical properties.

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