“…There were four different types of C atom in STTPs. The peak at 292.78 eV could be assigned to pure carbon, [44] and peak at 288.58 eV could be attributed to ‐C=O group [45] . The peak at 286.08 eV was referred to the functionalized carbons, such as C−O, C−S, or C−N, and peak at 284.78 eV was consistent with the non‐functionalized carbons of C−C and C−H [42] .…”
Sagittaria trifolia tuber is an aquatic vegetable. In this work, microwave‐assisted enzymatic extraction (MEE) was used to extract S. trifolia tuber polysaccharides (STTPs). Optimum conditions were complex enzyme of 2 %, liquid‐to‐solid ratio of 43 : 1 mL g−1, microwave power of 506 W, and time of 8 min, under which STTPs yield was 36.22±0.69 %, higher than those of other methods. STTPs were sulfated polysaccharides with sulfur valence of S6+. STTPs comprised mannose, glucose, galactose, and arabinose at a mole ratio of 3.69 : 19.33 : 6.21 : 1.00, molecular weights of 3606 kDa and 149.6 kDa, particle size of 220 nm, and zeta potential of −5.02 mV. The surface of STTPs was full of bumps and holes, and abundant in O1s and non‐functionalized C1s. STTPs would scavenge reactive oxygen species with advantage. It would provide an efficient MEE method to obtain antioxidant STTPs, also a clue for extracting polysaccharides from starch‐rich crops.
“…There were four different types of C atom in STTPs. The peak at 292.78 eV could be assigned to pure carbon, [44] and peak at 288.58 eV could be attributed to ‐C=O group [45] . The peak at 286.08 eV was referred to the functionalized carbons, such as C−O, C−S, or C−N, and peak at 284.78 eV was consistent with the non‐functionalized carbons of C−C and C−H [42] .…”
Sagittaria trifolia tuber is an aquatic vegetable. In this work, microwave‐assisted enzymatic extraction (MEE) was used to extract S. trifolia tuber polysaccharides (STTPs). Optimum conditions were complex enzyme of 2 %, liquid‐to‐solid ratio of 43 : 1 mL g−1, microwave power of 506 W, and time of 8 min, under which STTPs yield was 36.22±0.69 %, higher than those of other methods. STTPs were sulfated polysaccharides with sulfur valence of S6+. STTPs comprised mannose, glucose, galactose, and arabinose at a mole ratio of 3.69 : 19.33 : 6.21 : 1.00, molecular weights of 3606 kDa and 149.6 kDa, particle size of 220 nm, and zeta potential of −5.02 mV. The surface of STTPs was full of bumps and holes, and abundant in O1s and non‐functionalized C1s. STTPs would scavenge reactive oxygen species with advantage. It would provide an efficient MEE method to obtain antioxidant STTPs, also a clue for extracting polysaccharides from starch‐rich crops.
“…The appeared structures might be due to the application of KOH that was mixed with rice straw ash 49 . Along with, heating at a high temperature in a muffle furnace results in a material with a greater surface area and a higher mesoporosity 50 . Figure 1 Morphological characterization using high resolution microscopy.…”
Arsenic is a major global threat to the ecosystem. Here we describe a highly accurate sensing platform using silica nanoparticles/graphene at the surface of aluminum interdigitated electrodes (Al IDE), able to detect trace amounts of arsenic(III) in rice grain samples. The morphology and electrical properties of fabricated Al IDEs were characterized and standardized using AFM, and SEM with EDX analyses. Micrometer scale Al IDEs were fabricated with silicon, aluminum, and oxygen as primary elements. Validation of the bare Al IDE with electrolyte fouling was performed at different pH levels. The sensing surface was stable with no electrolyte fouling at pH 7. Each chemical modification step was monitored with current–volt measurement. The surface chemical bonds were characterized by fourier transform infrared spectroscopy (FTIR) and revealed different peaks when interacting with arsenic (1600–1000 cm−1). Both silica nanoparticles and graphene presented a sensitive limit of detection as measured by slope calibration curves at 0.0000001 pg/ml, respectively. Further, linear regression was established using ΔI (A) = 3.86 E−09 log (Arsenic concentration) [g/ml] + 8.67 E−08 [A] for silica nanoparticles, whereas for graphene Y = 3.73 E−09 (Arsenic concentration) [g/ml] + 8.52 E−08 on the linear range of 0.0000001 pg/ml to 0.01 pg/ml. The R2 for silica (0.96) and that of graphene (0.94) was close to the maximum (1). Modification with silica nanoparticles was highly stable. The potential use of silica nanoparticles in the detection of arsenic in rice grain extract can be attributed to their size and stability.
“…The SEM micrographs revealed graphene flakes with a rough surface. The activating agent KOH and the high thermal exfoliation process caused changes in the morphological structure of the sheets [17]. The SEM images obtained for GO @ RHA are much better than GO @ graphite powder.…”
Section: Scanning Electron Microscopy (Sem)mentioning
confidence: 99%
“…This is because the activated KOH mixed with the rice husk ash defines the particle microstructures. Furthermore, heating at a high temperature in a calcination furnace results in a material with a larger surface area and better mesoporosity [17]. TEM images of nanocellulose in figure 3(c) show circular shaped nanoparticles of NC @ cellulose powder.…”
Section: Transmission Electron Microscopy (Tem)mentioning
In this study, main focus has been drawn on the utilization of agricultural waste sources to synthesize nanomaterials. Graphene oxide and nanocellulose were prepared using rice husk ash and sugarcane bagasse, respectively. Further, their nanocomposites were also prepared in (1:1) ratio of graphene oxide and nanocellulose. The synthesized nanomaterials from agricultural waste were compared with those prepared from conventional sources through varied characterizations. Scanning electron microscopy, transmission electron microscopy, fourier transform infrared spectroscopy and N2 adsorption-desorption analysis was performed to examine the structural, functional and surface properties of the prepared nanomaterials from different precursors. High resolution imaging revealed better structural characteristics of the nanomaterials fabricated from agri-waste precursors. SEM images showed well exfoliated structure of GO and porous nature of NC. The folded layers of GO represent the presence of hydroxyl groups in the TEM images of GO @ graphite powder. TEM images of nanocellulose showed circular shaped nanoparticles of NC @ cellulose powder. Fourier transform infrared spectroscopy confirmed the presence of all the essential functional groups in the structure of prepared nanomaterials. The nanocomposites prepared using agricultural waste sources and conventional sources were inspected by N2 adsorption-desorption analysis, which demonstrated that the nanocomposites prepared from agri-waste sources exhibits much higher specific surface area than that of prepared from conventional precursors. R2 possess specific surface area of 82.832 m2/g while, R1 possess only 6.721 m2/g. N2 adsorption-desorption analysis revealed the pore volume, pore diameter, micropore volume, micropore area and surface area of the prepared nanocomposites. The nanomaterials prepared using agricultural waste products shows desirable characteristics in all aspects which makes them equally applicable in energy storage devices, food packaging, drug delivery systems, nanosensors and water filtration systems.
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