This study aimed to evaluate the effect of ammonium persulfate’s (APS) oxidation time on the characteristics of the cellulose nanocrystals (CNCs) of balsa and kapok fibers after delignification pretreatment with sodium chlorite/acetic acid. This two-step method is important for increasing the zeta potential value and achieving higher thermal stability. The fibers were partially delignified using acidified sodium chlorite for four cycles, followed by APS oxidation at 60 °C for 8, 12, and 16 h. The isolated CNCs with a rod-like structure showed an average diameter in the range of 5.5–12.6 nm and an aspect ratio of 14.7–28.2. Increasing the reaction time resulted in a gradual reduction in the CNC dimensions. The higher surface charge of the balsa and kapok CNCs was observed at a longer oxidation time. The CNCs prepared from kapok had the highest colloid stability after oxidation for 16 h (−62.27 mV). The CNCs with higher crystallinity had longer oxidation times. Thermogravimetric analysis revealed that the CNCs with a higher thermal stability had longer oxidation times. All of the parameters were influenced by the oxidation time. This study indicates that APS oxidation for 8–16 h can produce CNCs from delignified balsa and kapok with satisfactory zeta potential values and thermal stabilities.

Cellulose nanocrystals (CNCs) were successfully isolated from oil palm fronds (OPFs) using different concentrations of ammonium persulfate (APS), and their characteristics were analyzed by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis, and thermogravimetric analysis (TGA). APS oxidation effectively isolated CNCs with rod-like morphology in nanometer scale. The dimensions of the CNCs decreased with increasing APS concentration. FTIR and XRD analyses revealed that all the CNCs showed crystals in the form of cellulose I without crystal transformation occurring during APS treatment. The relative crystallinity of the CNCs increased with increasing APS concentration, whereas their thermal stability decreased. An APS concentration of 2 M was found to be optimal for isolating the CNCs.

Chemical components content of seven Indonesian bamboo species were investigated. Bamboo species used in this study including Andong bamboo (Gigantochloa pseudoarundinacea), Tali bamboo (G.apus), Hitam bamboo (G. artoviolacea), Betung bamboo (Dendrocalamus asper), Sembilang bamboo (D. giganteus), Ampel bamboo (Bambusa vulgaris var. vulgaris), and Kuning bamboo (B. vulgaris var. striata). Holocellulose, alphacellulose, Klason lignin, acid-soluble lignin, extractives content, and pH value were determined. The highest holocellulose and alphacellulose content were found in Ampel and Hitam bamboo, respectively. Sembilang bamboo has the highest lignin content. Generally, Ampel bamboo has the highest extractives content. The pH value of the seven bamboo species showed that all bamboo species tend to be acidic.

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biodegradable polymer such as PVA is considered the most promising candidates for developing the sustainable sticker. The objective of this study was to determine the most suitable PVA + TS blends as adhesives agent for AMF spores inoculation via seed coating which can enhance the spores viability and their beneficial properties in maize. The polythene bag experiment was performed in a screen house of the Department of Plant Protection Faculty of Agriculture, University of Bengkulu Indonesia in 2015. Six adhesive blends were employed: 100% PVA + 0% TS, 75% PVA + 25% TS, 50% PVA + 50% TS, 25% PVA + 75% TS, 0% PVA + 100% TS, and no coating. The six experimental treatments were laid out in a completely randomized design with three replications. The results show that root colonization, AMF spore population, and shoot dry weight in 75% PVA + 25% TS were equal to those in 100% PVA. Root colonization, AMF spore population, shoot P content, and shoot P concentration were greater for 50% PVA + 50% TS than 100% PVA, 100% TS, and no coating. A mixture of 50% PVA + 50% TS was considered the preferred sticker. Thus, the tapioca starch can be used to substitute 25 - 50% of the PVA used without reducing AMF inoculant adhering to seed.Keywords: polymeric seed coating, seed coating formulation, arbuscular mycorrhizal fungi, sustainable coating adhesive, seed inoculation, seed inoculant