Characterization and analysis of novel natural cellulosic fiber extracted from Strelitzia reginae plant

The purpose of this study is to evaluate in detail the usability of new cellulosic fibers extracted from the stem of the plant Strelitzia reginae, as a potential reinforcement for polymer composites. The morphological, physical, thermal, and mechanical properties of fibers were addressed for the first time in this paper. Both untreated and alkali-treated fibers were characterized, using scanning electron microscopy (SEM), Fourier-transform infrared, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), optical microscope, and X-ray diffraction (XRD) and applying tensile test for determining the mechanical behavior. For both fiber treated at one hour (T1H) and at four hours (T4H), the stem anatomy and fiber SEM micrographs showed a strong presence of fiber cells. Thermogravimetry and DSC showed that the fiber was thermally stable up to 233°C for untreated fiber, 254 and 240°C, respectively, In single-fiber tensile tests, it was observed that the fibers extracted from the stem of Strelitzia reginae were strong. The mean values of Young’s modulus exhibited by untreated fibers and treated (T1H) and (T4H) are, respectively, 9.89 GPa, 12.08, and 18.39 GPa. Also mean values of tensile strength are 271.79, 306.23, and 421.39 MPa. The XRD reveals the presence of cellulose with a Crystallinity Index of 70% for raw fiber and 72% for the treated one. Fourier-transform infrared analysis well demonstrated the effect of chemical treatment. It can be concluded from the results of all above experiments that the Strelitzia reginae fibers (SR) could serve as a possible reinforcement in composite materials.

EXTENDING VASE LIFE OF CUT Strelitzia reginae Aiton FLOWERS BY COBALT CHLORIDE, CERIUM NITRATE, SILVER NANOPARTICLES AND NANOSIL

Cut flowers of Strelitzia reginae Aiton (Strelitziaceae) generally have a short vase life. Vascular blockage is a major reason for this. In this paper, we evaluated the effects of pulse treatment with disinfectants including cobalt chloride (CoCl2), cerium nitrate (Ce(NO3)3), silver nanoparticles (SNP) and Nanosil on the vase life and physiological characteristics of cut S. reginae flowers stems. Cut flowers kept in the vase solution containing these disinfectants showed significant increase in solution uptake, the content of total protein and pigments of petals, the activities of antioxidantive active enzymes superoxide dismutase (SOD) and ascorbate peroxidase (APX). Also, the number of stem-end bacteria and malondialdehyde (MDA) content in cut flowers were decreased as compared to control. Based on obtained results, we introduce Ce(NO3)3 as the most effective treatment to extend the vase life of cut S. reginae flowers. More so with the concentration of 300 µM which induced the maximum solution uptake and SOD and APX activities that resulted in the longest vase life. Findings of the present study suggested that Ce(NO3)3 prolonged postharvest longevity of S. reginae by increasing the solution uptake and SOD and APX activity and decreasing the MDA content. The use of Ce(NO3)3 reduces the use of chemicals and make saving in costs. The highest bacterial population of micro-organisms on cut stem ends were Escherichia coli, Bacillus, Staphylococcus and Streptococcus. Cerium nitrate had the strongest effect on reduction of these bacterial population and yeast.

Hydrodynamic Parameters of Strelitzia Gum

The flower of Strelitzia reginae generates abundant and viscous mucilage as exudate, which is purified in periods of heating–cooling, and finally precipitated with ethanol, obtaining strelitzia gum (StrG). By means of intrinsic viscosity measurement, the viscometric molecular weight (MWv) is determined, with a value of 200,000 g/mol, as well as a hydrodynamic radius of 20 ± 1 nm and a hydration value of 445 ± 34 g/g. The size of StrG was compared against dynamic light scattering data with a value of 16 ± 2 nm and a MWDLS of 230,000 g/mol. StrG is a biopolyelectrolyte with an “a” value of 0.85, which corresponds to a flexible behavior with a great effect of volume exclusion. This statement is based on the difficulty of gum dissolution, that should be performed at 80 °C. This macromolecule is very promising and can potentially be used in several industrial applications, such as in film forming, and as a gel, thickener, and coemulsifier.