scholarly journals Influence of Reaction pH towards the Physicochemical Characteristics of Phosphorylated Polyvinyl Alcohol-Aluminum Hosphate Nanocomposite

Coatings ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1105
Author(s):  
Asmalina Mohamed Saat ◽  
Md Salim Kamil ◽  
Nor Aliya Hamizi ◽  
Irfan Anjum Badruddin ◽  
Nadiah Ghazali ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Polyvinyl Alcohol ◽  
Spherical Shape ◽  
Aluminum Phosphate ◽  
Physicochemical Characteristics ◽  
Step Process ◽  
Vis Spectroscopy ◽  
Surface Nature

The present study deals with the formation of a phosphorylated polyvinyl alcohol (PPVA)-Aluminum Phosphate (AlPO4) nanocomposite, changing the pH solution under the two-step process involving the phosphorylation of polyvinyl alcohol (PVA) followed by the conjugation with AlPO4. The composite was formed by varying the pH of the solution in the range of 7–12 and the reflected changes in the product’s morphology, crystallinity, surface nature, thermal stability, etc. were recorded using FESEM, XRD, FTIR, UV-Vis spectroscopy, TGA, etc. From the analysis, it was found that the particles formed with two different sizes of the probed pH, and at pH 10 they were homogeneously distributed. In addition, the morphology of the PPVA-AlPO4 composite also seems to be altered with respect to the pH and this is due to the differences in the amount of H+ and OH− anions. Thus, from the overall analysis, it can be indicated that pH 10 needs to be maintained for the formation of a spherical shape and uniformly distributed PPVA-AlPO4 nanocomposite.

scholarly journals Physicochemical characteristics of chitosan from swimming crab (Portunus trituberculatus) shells prepared by subcritical water pretreatment

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gengxin Hao ◽  
Yanyu Hu ◽  
Linfan Shi ◽  
Jun Chen ◽  
Aixiu Cui ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Sodium Hydroxide ◽  
Subcritical Water ◽  
Physicochemical Characteristics ◽  
Ash Content ◽  
Portunus Trituberculatus ◽  
Swimming Crab ◽  
Water Pretreatment ◽  
Thermal Stability Of

AbstractThe physicochemical properties of chitosan obtained from the shells of swimming crab (Portunus trituberculatus) and prepared via subcritical water pretreatment were examined. At the deacetylation temperature of 90 °C, the yield, ash content, and molecular weight of chitosan in the shells prepared via subcritical water pretreatment were 12.2%, 0.6%, and 1187.2 kDa, respectively. These values were lower than those of shells prepared via sodium hydroxide pretreatment. At the deacetylation temperature of 120 °C, a similar trend was observed in chitosan molecular weight, but differences in chitosan yield and ash content were not remarkable. At the same deacetylation temperature, the structures of chitosan prepared via sodium hydroxide and subcritical water pretreatments were not substantially different. However, the compactness and thermal stability of chitosan prepared via sodium hydroxide pretreatment was lower than those of chitosan prepared via subcritical water pretreatment. Compared with the chitosan prepared by sodium hydroxide pretreatment, the chitosan prepared by subcritical water pretreatment was easier to use in preparing oligosaccharides, including (GlcN)2, via enzymatic hydrolysis with chitosanase. Results suggested that subcritical water pretreatment can be potentially used for the pretreatment of crustacean shells. The residues obtained via this method can be utilized to prepare chitosan.

scholarly journals The Development of the Innovative Synthesis Methodology of Albumin Nanoparticles Supported by Their Physicochemical, Cytotoxic and Hemolytic Evaluation

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4386
Author(s):  
Sonia Kudłacik-Kramarczyk ◽  
Anna Drabczyk ◽  
Magdalena Głąb ◽  
Paweł Gajda ◽  
Anna Czopek ◽  
...  
Keyword(s):  
Spherical Shape ◽  
Dermal Fibroblasts ◽  
Albumin Concentration ◽  
Salting Out ◽  
Tem Analysis ◽  
Albumin Nanoparticles ◽  
Vis Spectroscopy ◽  
Physicochemical Evaluation ◽  
Normal Human ◽  
Synthesis Methodology

Many studies are being performed to develop effective carriers for controlled cytostatic delivery wherein albumin is a promising material due to its tendency to accumulate near cancer cells. The novelty of this work involves the development of the synthesis methodology of albumin nanoparticles and their biological and physicochemical evaluation. Albumin particles were obtained via the salt-induced precipitation and K3PO4 was used as a salting-out agent. Various concentrations of protein and salting-out agent solutions were mixed using a burette or a syringe system. It was proved that the size of the particles depended on the concentrations of the reagents and the methodology applied. As a result of a process performed using a burette and 2 M K3PO4, albumin spheres having a size 5–25 nm were obtained. The size of nanospheres and their spherical shape was confirmed via TEM analysis. The use of a syringe system led to preparation of particles of large polydispersity. The highest albumin concentration allowing for synthesis of homogeneous particles was 2 g/L. The presence of albumin in spheres was confirmed via the FT-IR technique and UV-Vis spectroscopy. All samples showed no cytotoxicity towards normal human dermal fibroblasts and no hemolytic properties against human erythrocytes (the hemolysis did not exceed 2.5%).

Synthesis of Fine Nickel Powders by Solvothermal Method

2007 ◽  
Vol 334-335 ◽  
pp. 1145-1148 ◽  
Author(s):  
Yin Ye ◽  
Fang Li Yuan ◽  
Li Min Zhou ◽  
Hai Tao Huang
Keyword(s):  
Thermal Stability ◽  
Chemical Reduction ◽  
Spherical Shape ◽  
Butyl Alcohol ◽  
Nickel Powders ◽  
Good Crystallinity ◽  
Average Size ◽  
Solvothermal Conditions ◽  
Thermal Stability Of ◽  
Fine Nickel

Fine nickel powders have been prepared by chemical reduction between nickel acetate and alcohol under solvothermal conditions. The effect of adding surfactant and varying solvent on the particle size of the as-synthesized nickel powders have been explored. SEM, XRD and TG were employed to characterize the size, morphology, crystalline structure and the thermal stability of the as-synthesized nickel powders. It is revealed that the FCC-structured nickel powders are of uniform spherical shape with good crystallinity and thermal stability. Typically, nickel powders with an average size of 300 nm were obtained at 200°C for 8 h using 0.04 mol/L solution of Ni(CH3COO)2·4H2O in n-butyl alcohol under solvothermal conditions.

scholarly journals Copper (0) Mediated Single Electron Transfer-Living Radical Polymerization of Methyl Methacrylate: Functionalized Graphene as a Convenient Tool for Radical Initiator

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 874 ◽  
Author(s):  
Adhigan Murali ◽  
Srinivasan Sampath ◽  
Boopathi Appukutti Achuthan ◽  
Mohan Sakar ◽  
Suryanarayanan Chandrasekaran ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Electron Transfer ◽  
Methyl Methacrylate ◽  
Radical Polymerization ◽  
Living Radical Polymerization ◽  
Single Electron ◽  
Single Electron Transfer ◽  
Functionalized Graphene ◽  
Radical Initiator ◽  
Vis Spectroscopy

Polymer nanocomposites have been synthesized by the covalent addition of bromide-functionalized graphene (Graphene-Br) through the single electron transfer-living radical polymerization technique (SET-LRP). Graphite functionalized with bromide for the first time via an efficient route using mild reagents has been designed to develop a graphene based radical initiator. The efficiency of sacrificial initiator (ethyl α-bromoisobutyrate) has also been compared with a graphene based initiator towards monitoring their Cu(0) mediated controlled molecular weight and morphological structures through mass spectroscopy (MOLDI-TOF) and field emission scanning electron microscopy (FE-SEM) analysis, respectively. The enhancement in thermal stability is observed for graphene-grafted-poly(methyl methacrylate) (G-g-PMMA) at 392 °C, which may be due to the influence ofthe covalent addition of graphene, whereas the sacrificial initiator used to synthesize G-graft-PMMA (S) has low thermal stability as analyzed by TGA. A significant difference is noticed on their glass transition and melting temperatures by DSC. The controlled formation and structural features of the polymer-functionalized-graphene is characterized by Raman, FT-IR, UV-Vis spectroscopy, NMR, and zeta potential measurements. The wettability measurements of the novel G-graft-PMMA on leather surface were found to be better in hydrophobic nature with a water contact angle of 109 ± 1°.

Study of the structure and thermal characteristics of nanocomposites based on polyvinyl alcohol and intercalated montmorillonite

2019 ◽  
pp. 089270571987919
Author(s):  
Volodymyr Krasinskyi ◽  
Ivan Gajdos ◽  
Oleh Suberlyak ◽  
Viktoria Antoniuk ◽  
Tomasz Jachowicz
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Acrylic Acid ◽  
Polyvinyl Alcohol ◽  
Thermal Characteristics ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
The Degree Of Crystallinity

The structure and thermal characteristics of nanocomposites based on polyvinyl alcohol (PVA) and montmorillonite (MMT) intercalated with polyvinylpyrrolidone were investigated by X-ray diffraction analysis and differential scanning calorimetry. The modification of PVA with intercalated MMT reduces the degree of crystallinity of the resulting nanocomposites but significantly increases their thermal stability. Under ultrasound, the intercalated MMT was completely distributed in a PVA solution and formed a monocrystalline structure. Films based on PVA with modified MMT were cross-linked at 110°C in the presence of 5 wt% acrylic acid and 0.5 wt% Ferrous(II) sulfate as an initiator. The formed films have a homogeneous cross-linked structure.

scholarly journals Silver Nanoparticles Synthesized by Using Bacillus cereus SZT1 Ameliorated the Damage of Bacterial Leaf Blight Pathogen in Rice

Pathogens ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 160 ◽  
Author(s):  
Temoor Ahmed ◽  
Muhammad Shahid ◽  
Muhammad Noman ◽  
Muhammad Bilal Khan Niazi ◽  
Faisal Mahmood ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Bacillus Cereus ◽  
Plant Biomass ◽  
Spherical Shape ◽  
Leaf Blight ◽  
Bacterial Leaf Blight ◽  
Rrna Gene ◽  
Vis Spectroscopy ◽  
Bacterial Culture Supernatant

Amongst serious biotic factors deteriorating crop yield, the most destructive pathogen of rice is Xanthomonas oryzae pv. oryzae (Xoo), which causes bacterial leaf blight (BLB) disease. This study involved targeted use of biogenic silver nanoparticles (AgNPs) to control BLB in order to cope with the disadvantages of chemical disease control. AgNPs were biologically synthesized from natively isolated Bacillus cereus strain SZT1, which was identified through 16S rRNA gene sequence analysis. Synthesis of AgNPs in bacterial culture supernatant was confirmed through UV-VIS spectroscopy. Fourier transform infrared spectroscopy (FTIR) confirmed that the existence of AgNPs was stabilized with proteins and alcoholic groups. X-ray diffraction (XRD) data revealed the crystalline nature and imaging with scanning electron microscopy (SEM) and transmission electron microscopy (TEM), showing the spherical shape of AgNPs with particle sizes ranging from 18 to 39 nm. The silver presence in AgNPs was further confirmed by energy dispersive spectra. Biogenic AgNPs showed substantial antibacterial activity (24.21 ± 1.01 mm) for Xoo. In a pot experiment, AgNPs were found to be effective weapons for BLB by significantly increasing the plant biomass with a decreased cellular concentration of reactive oxygen species and increased concentration of antioxidant enzyme activity.

High Mobility IGZO/ITO Double-layered Transparent Composite Electrode: A Thermal Stability Study

2013 ◽  
Vol 1577 ◽  
Author(s):  
Aritra Dhar ◽  
T. L. Alford
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Electrical Properties ◽  
Indium Tin Oxide ◽  
High Mobility ◽  
Bottom Layer ◽  
Optoelectronic Device ◽  
Stability Study ◽  
Visible Range ◽  
Vis Spectroscopy

ABSTRACTThe fabrication of a thin film optoelectronic device involves the exposure of the transparent conductive oxide (TCO) to a high process temperature. Indium gallium zinc oxide (InGaZnO4 or IGZO) is a well known TCO with high optical transparency, moderate conductivity and high mobility. However, its electrical properties deteriorate after subsequent high temperature processes in air atmosphere. On the other hand indium tin oxide (ITO) has higher conductivity than IGZO and better thermal stability. Therefore, IGZO/ITO bilayers have been deposited on glass by radio frequency magnetron sputtering at room temperature and subsequently annealed at high temperatures in order to study their thermal stability. In the present work, a-IGZO layers with a thickness ranging from 10 nm to 100 nm were deposited over a 50 nm thick ITO layer. Results are compared with those from a single IGZO layered thin film without the ITO bottom layer. The structural, optical and electrical properties of the multilayers are studied with the use of scanning electron microscopy, UV–Vis spectroscopy and Hall measurement. An IGZO optimal thickness of 50 nm is found to improve the bilayer thermal stability at temperatures upto 400 °C keeping good opto-electrical properties. The sheet resistance for the optimized IGZO/ITO composite films is about 22 Ohm/sq, and the transmittance in the visible range is about 90%. The composite shows an excellent mobility above 40 cm2 /V-s and thus can be potentially applied as channel layer in thin film transistors (TFTs)

Preparation and Optimization of a Live Newcastle Disease Virus Vaccine Encapsulated in Chitosan Nanoparticles

2013 ◽  
Vol 662 ◽  
pp. 149-152
Author(s):  
Yan Hao ◽  
Hao Wu ◽  
Wei Li ◽  
Xiao Mei Luo ◽  
Kai Zhao
Keyword(s):  
Virus Vaccine ◽  
Chitosan Nanoparticles ◽  
Influence Factors ◽  
Spherical Shape ◽  
Entrapment Efficiency ◽  
Physicochemical Characteristics ◽  
Ionic Gelation ◽  
Synthetic Vaccines ◽  
Average Size ◽  
Newcastle Disease Virus Vaccine

In this study, the researcher’s interest is focused on establishing a model with La Sota live vaccine immobilized into chitosan, which was prepared using a ionic gelation method. The formulation, preparation procedure, influence factors, physicochemical characteristics were evaluated. The results of study demonstrate that the NDV-CS-NPs have been produced with suitable size, morphous regulation, extremely spherical shape, regular and well-distributed. The NDV-CS-NPs produced by the optimal formulation were average size (371.1nm) and proper zata potential (+2.84 mV). The entrapment efficiency was (74±3.7) %. It can provide a new useful information for the development and evaluation of synthetic vaccines.

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