Aynaz Holakoyi; Omid Ramezani; Hossein Kermanian; Faranak Mohammad Kazemi
Abstract
Introduction: Due to the hydrophilic nature of cellulose, nanofibrillated cellulose (NFC) is supplied in low solid content and high viscosity. As a cost saving strategy, increasing the possible highest solid content is preferred, which is hardly feasible owing to the irreversible hydrogen bonding formation ...
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Introduction: Due to the hydrophilic nature of cellulose, nanofibrillated cellulose (NFC) is supplied in low solid content and high viscosity. As a cost saving strategy, increasing the possible highest solid content is preferred, which is hardly feasible owing to the irreversible hydrogen bonding formation during drying. This phenomenon known as Hornification prevents the cellulose nanofibrils to be readily dispersed in water after being dried. This research assessed an environmentally friendly procedure for the production of water-dispersible nanofibrillated cellulose powder based on carboxymethyl cellulose (CMC) absorption. Material and methods: The absorption of varying amounts of CMC (0, 20 and 40 ml to constant 100 ml NFC) on cellulose nanofibrils in different temperatures of 22 °C (ambient) and 121 °C (autoclave) was investigated using conductometric titration. As the innovative part of the project, hydrodynamic properties of the dispersed NFC suspension including viscosity, turbidity, hydrodynamic specific volume, and water uptake were explored. Besides, the size of powder particles was probed by Dynamic Light Scattering (DLS). Results and discussion: The results indicated that in the highest addition level of CMC (40 ml) and autoclaving at 121 °C for 25 min, the highest absorption was observed, which yielded maximum results in all hydrodynamic properties compared to the control and other treated samples. On the contrary, data recorded for DLS signified that Poly Dispersity Index and the hydrodynamic diameter of the treated samples were bigger than untreated NFC, which was ascribed to the aggregation and agglomeration of cellulose particles in aqueous media. Conclusion: Based on the method presented in this research, NFC powders with suitable dispersibility were obtained after oven-drying. It is concluded that the addition of adequate CMC to NFC results in increased dispersion and waster absorption capacity. The achievements of this novel method facilitates the production, handling, and storage of NFC in industrial applications.
Shahram Namdjoyan; Hossein Kermanian; Ali Abolhasani Soorki; Sedigheh Modarres Tabatabaei; Nazli Elyasi
Volume 15, Issue 3 , October 2017, , Pages 109-122
Abstract
Introduction:
It was shown that the use of signaling molecules like nitric oxide donor sodium nitroprusside (SNP) can elevate phytoremediation potential of some plant species. The aim of the study is to reveal the effect of SNP on the enhancement of the phytoremediation potential and physiological responses ...
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Introduction:
It was shown that the use of signaling molecules like nitric oxide donor sodium nitroprusside (SNP) can elevate phytoremediation potential of some plant species. The aim of the study is to reveal the effect of SNP on the enhancement of the phytoremediation potential and physiological responses of zinc-stressed safflower roots.
Material and methods:
The treatments were arranged in a completely randomized design with five replicates. After 10 days, the level of oxidative markers (e.g., H2O2 and lipid peroxidation) and antioxidant compounds (e.g., glutathione, ascorbate and phytochelatins) of plants were analyzed.
Results and discussion:
SNP application alleviated Zn-induced growth inhibition of roots probably through induction of some antioxidative compounds.Application of SNP resulted in decrease in oxidative markers and the activity of SOD as compared to the plants treated with Zn only. No relationship was found between SNP supplementation and glutathione and ascorbate levels, while upon application of SNP the level of PCs increased significantly.
Conclusion:
The results suggest that the application of SNP render safflower roots more tolerant to zinc toxicity possibly through zinc chelation by the stimulation of phytochelatin production.
