No abstract

Research on hydrogels as soil conditioners has been developed based on hydrogels copolymerized with composite materials in the form of chitosan and TiO 2 to overcome low physical properties and low swelling of polyacrylamide. The aims of the study are synthesis, characterization, application of hydrogels, and determination of the physical and chemical properties of soil and the growth of soybean plants. Synthesis of chitosan-co-polyacrylamide-TiO 2 crosslinked glutaraldehyde hydrogel was prepared by the chemical crosslinking method. The characterization of hydrogel was performed by using Fourier Transform Infra-Red (FTIR) and Scanning Electron Microscope (SEM). FTIR spectrum shows the functional groups of chitosan co-polyacrylamide-TiO 2 crosslinked glutaraldehyde which includes OH functional groups (3408.22 cm-1), NH (1602.85 cm-1), C=O (1502 cm-1), CN (1600.92 cm-1), and Ti-O (619.15 cm-1). The SEM image shows the formation of pores and cavities in the hydrogel. The application of hydrogels in soybean plants shows differences in physical and chemical properties of soil and plant growth. The use of all variations of hydrogel had no signifi cant effect on soil physical properties including temperature, humidity, and bulk density. Meanwhile, hydrogels with TiO 2 concentration of 60 ppm infl uence signifi cantly to the chemical properties of soil such as organic carbon, cation exchange capacity (CEC), and level of nitrogen, phosphorus, and potassium in the soil. The optimum number of leaves, plant height, total dry weight are 68 leave blades, 207 cm, and 20.6 g, respectively. This optimum condition was found in the use of KTiKPAG60 hydrogel. The results showed that chitosan-co-polyacrylamide-TiO 2 crosslinked glutaraldehyde has the potential to be a soil conditioner.

Chitosan co-polyacrylamide hydrogel crosslinked has been prepared by glutaraldehyde to obtain the unique material as soil remediation for agriculture applications which play a role in water storage to increase plant fertility. In this study, we examine the compositions effect of hydrogel material, the optimum concentration of glutaraldehyde as crosslinker, and hydrogel properties. Based on the results, the hydrogel successfully synthesized through chemical crosslinking methods that the 0.53 g, 1.06 g, and 1.59 g of glutaraldehyde to (0.9:5.1), (1.2:4.8) and (1.5:4.5) grams of chitosan and acrylamide were used to increase the degree of swelling properties KKPAG105 396.17% (0.9:5.1) and KKPAG205 262.51% (1.2:4.8), respectively. Subsequently, Fourier-transform infrared spectroscopy (FTIR) was characterized to identify functional groups of hydrogel material shows that the existing functional groups of OH overlapping with NH at 3446.72 cm-1 from chitosan, C=O at 1633.49 cm-1 from glutaraldehyde, and C=N 1433.11 cm-1 from polyacrylamide. In addition, morphologically has been identified by Scanning Electron Microscope (SEM) that the chitosan co-polyacrylamide hydrogel crosslinked by glutaraldehyde which is pores formed for passing water absorption. Based on this study, we can be able to utilize in regeneration of soil mining area.

This research is on the manufacture of chitosan hydrogel crosslinked with malonic acid to be used as a soil conditioner for soybean plant (glycine max L. merrill). The aim of the study is to determine the effect of chitosan composition on malonic acid and the characteristics of hydrogel, and the effect of hydrogel as soil conditioner—its physical and chemical properties and role in soybean plant growth. Hydrogel of chitosan crosslinked malonic acid is carried out through a crosslinking chemical method. The increase in chitosan and malonic acid concentration can increase the swelling degree of hydrogel by 285.32%. Characterization is done using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). FTIR analysis shows changes in the specific absorption between chitosan and chitosan crosslinked malonic acid that occurs in the area of wave number 1080 cm−1 (C─O). SEM analysis shows that the increase in chitosan composition and malonic acid concentration causes the surface structure to be rough, hollow, and irregular. The use of hydrogel on soil conditions of soybean plants at 75th day measurements which give the most significant positive response is chitosan: malonic acid (2.5 g: 2.5%). Moisture value, soil temperature, C‐organic content, absorbed potassium level, and cation exchange capacity (CEC) content are 50%, 27–30 °C, 2%, 20.54 ppm, and 17.74 meq/100 g, respectively. In addition, the effect of hydrogel use on soybean plants result in the plant reaching a maximum height of 93 cm on the 75th day. The chitosan–malonic acid hydrogel has potential as soil conditioner.