scholarly journals Synthesis, Characterization and Properties of Antibacterial Polyurethanes

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 213
Author(s):  
Jihua Duan ◽  
Guichang Jiang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Self Assembly ◽  
Gel Permeation Chromatography ◽  
Gray Mold ◽  
Proton Nuclear Magnetic Resonance ◽  
Step Method ◽  
Chemical Structures ◽  
Physically Crosslinked ◽  
Scanning Electron

Novel physically crosslinked polyurethane (PUII), based on isophorone diisocyanates, was prepared by a conventional two-step method. The chemical structures of the PUII were characterized by fourier transform infrared (FTIR), proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), scanning electron microscopy (SEM) and DSC. The PUII hydrogels were subjected to solvent-induced self-assembly in THF + water to construct a variety of morphologies. The self-assembly morphology of the PUII was observed by scanning electron microscopy (SEM). The PUII films with different amounts (0.2%, 0.4%, 0.6%, 0.8%, 1.0%) of 1,3,5-Tris(2-hydroxyethyl)hexahydro-1,3,5-triazine (TNO) were challenged with Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Gray mold. The results showed that when a small amount of antibacterial agent were added, the antibacterial effect of films on Botrytis cinerea was more obvious. The mechanical evaluation shows that the antimicrobial polyurethane films exhibit good mechanical properties.

Effect of TiC on coarsening and macrosegregation of Al–Bi alloys

2020 ◽  
Vol 111 (7) ◽  
pp. 607-615
Author(s):  
Congmin Li ◽  
Yanguo Yin ◽  
Ming Xu ◽  
Jianfeng Cheng ◽  
Lan Shen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Heterogeneous Nucleation ◽  
Self Assembly ◽  
Holding Time ◽  
Energy Dispersive ◽  
Melt Temperature ◽  
X Ray ◽  
Minority Phase ◽  
Scanning Electron

Abstract The microstructures of an Al-Bi immiscible alloy and the corresponding composites containing TiC (1 wt.% and 2 wt.%) were explored for melt temperatures of 800 °C, 850 °C, and 900°C. It was demonstrated that serious coarsening and macrosegregation of Bi-rich minority phase particles occurred, which was slightly alleviated by increasing the melt temperature from 800 °C to 900 °C. By adding TiC particles, the coarsening and macrosegregation of Bi-rich minority phase particles were significantly impeded. Scanning electron microscopy and energy-dispersive X-ray spectroscopy revealed that TiC particles were located inside and on the surface of Bi-rich minority phase particles, exhibiting heterogeneous nucleation and self-assembly behaviour. By properly increasing the holding time of the melt, finer and more uniform Bi-rich minority phase particles were obtained.

scholarly journals Improving the reactivity of phenylacetylene macrocycles toward topochemical polymerization by side chains modification

2014 ◽  
Vol 10 ◽  
pp. 1613-1619 ◽  
Author(s):  
Simon Rondeau-Gagné ◽  
Jules Roméo Néabo ◽  
Maxime Daigle ◽  
Katy Cantin ◽  
Jean-François Morin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Raman Spectroscopy ◽  
Self Assembly ◽  
Significant Enhancement ◽  
Side Chains ◽  
X Ray Diffraction ◽  
X Ray ◽  
Topochemical Polymerization ◽  
Scanning Electron

The synthesis and self-assembly of two new phenylacetylene macrocycle (PAM) organogelators were performed. Polar 2-hydroxyethoxy side chains were incorporated in the inner part of the macrocycles to modify the assembly mode in the gel state. With this modification, it was possible to increase the reactivity of the macrocycles in the xerogel state to form polydiacetylenes (PDAs), leading to a significant enhancement of the polymerization yields. The organogels and the PDAs were characterized using Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM).

Synthesis of PZT Disks by a Hydrothermal Method

2012 ◽  
Vol 174-177 ◽  
pp. 592-595
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Method ◽  
Formation Mechanism ◽  
Powder Diffraction ◽  
Self Assembly ◽  
Hydrothermal Process ◽  
X Ray ◽  
Extended Length ◽  
Scanning Electron

The organization of nanostructures across extended length scales is a key challenge in the design of integrated materials with advanced functions. PbZr0.52Ti0.48O3multilayer disks which were constructed by oriented rectangle nanoparticles were easily prepared by a simple surfactant-free hydrothermal process. The as-prepared powders were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results indicated that the as-prepared PZT disks were constructed by self-assembly of rectangle nanoparticles by a perfect manner. The formation mechanism of the products was discussed.

scholarly journals Synthesis of Thermo-Responsive Block-Graft Copolymer Based on PCL and PEG Analogs, and Preparation of Hydrogel via Click Chemistry

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 765 ◽  
Author(s):  
Pei Shang ◽  
Jie Wu ◽  
Xiaoyu Shi ◽  
Zhidan Wang ◽  
Fei Song ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graft Copolymer ◽  
Self Assembly ◽  
Three Dimensional ◽  
Cycloaddition Reaction ◽  
Temperature Response ◽  
Gel Permeation Chromatography ◽  
Proton Nuclear Magnetic Resonance ◽  
Fluorescence Probes ◽  
Different Temperatures

Thermo-responsive cross-linkable mPEG-b-[PCL-g-(MEO2MA-co-OEGMA)]-b-mPEG was synthesized by ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP). Then, the cross-linkable block-graft copolymer was used to prepare hydrogel via a copper-catalyzed 1,3-dipolar azide-alkyne cycloaddition reaction. The chemical structure and composition of copolymer were characterized by proton nuclear magnetic resonance (1H NMR), Fourier-transform infrared (FT-IR) and gel permeation chromatography (GPC). The self-assembly behaviors of the copolymer in aqueous solution were studied by UV spectrophotometer, fluorescence probes, the surface tension method, dynamic light scattering, and transmission electron microscopy. The results proved that the copolymer has excellent solubility and better temperature response. The three-dimensional network structure of the gels, observed by scanning electron microscopy at different temperatures, indicated that the gels have temperature response.

Polymer-Assisted Hydrothermal Synthesis of PbTiO3 Crystals

2012 ◽  
Vol 528 ◽  
pp. 176-179
Author(s):  
Yong Gang Wang ◽  
Lin Lin Yang ◽  
Xin Wang ◽  
Song Li ◽  
Yu Jiang Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Hydrothermal Synthesis ◽  
Formation Mechanism ◽  
Powder Diffraction ◽  
Self Assembly ◽  
Hydrothermal Process ◽  
X Ray ◽  
Assembly Structure ◽  
Scanning Electron

Using polymer as a surfactant, we successfully synthesized of PbTiO3 crystals with a self-assembly structure by a hydrothermal process. The as-obtained powders were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results show that the presence of PVP, PEG and PVA plays a key role on the formation of self-assembly structure and the corresponding formation mechanism was briefly discussed.

scholarly journals Manilkara zapota (Linn.) Seeds: A Potential Source of Natural Gum

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Sudarshan Singh ◽  
Sunil B. Bothara
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Gel Permeation Chromatography ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manilkara Zapota ◽  
Gel Permeation ◽  
Scanning Electron

Mucilage isolated from seeds of Manilkara zapota (Linn.) P. Royen syn. is a plant growing naturally in the forests of India. This mucilage is yet to be commercially exploited, and characterized as polymer. Various physicochemical methods like particle size analysis, scanning electron microscopy, thermal analysis, gel permeation chromatography, X-ray diffraction spectrometry, zeta potential, Fourier transform infrared spectroscopy, and nuclear magnetic resonance spectroscopy have been employed to characterize this gum in the present study. Particle size analyses suggest that mucilage has particle size in nanometer. Scanning electron microscopy analysis suggests that the mucilage has irregular particle size. The glass transition temperature of the gum was observed to be 138°C and 136°C by differential scanning calorimetry and differential thermal analysis, respectively. The thermogravimetric analysis suggested that mucilage had good thermal stability. The average molecular weight of mucilage was determined to be 379180, by gel permeation chromatography, while the viscosity of mucilage was observed to be 219.1 cP. The X-ray diffraction spectrometry pattern of the mucilage indicates a completely amorphous structure. Elemental analysis of the gum revealed the contents of carbon, hydrogen, nitrogen, and sulfur to be 80.9 (%), 10.1 (%), 1.58 (%), and 512 (mg/kg), respectively. Mucilage had specific content of calcium, magnesium, potassium, lower concentrations of aluminum, cadmium, cobalt, lead, and nickel. The major functional groups identified from FT-IR spectrum include 3441 cm−1 (–OH), 1660 cm−1 (Alkenyl C–H & C=C Stretch), 1632 cm−1 (–COO–), 1414 cm−1 (–COO–), and 1219 cm−1 (–CH3CO). Analysis of mucilage by paper chromatography and 1D NMR, indicated the presence of rhamnose, xylose, arabinose, mannose, and fructose.

Preparation and Study of P(Styrene-Divinylbenzene)/Polyacrylamide Particles

2014 ◽  
Vol 1004-1005 ◽  
pp. 282-285
Author(s):  
Jian Li Wang ◽  
Zhong Hua Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Infrared Spectroscopy ◽  
Emulsion Polymerization ◽  
Diameter Distribution ◽  
Step Method ◽  
Styrene Divinylbenzene ◽  
Concentrated Emulsion ◽  
Scanning Electron

The micro-sized p(styrene-1,4-divinylbenzene)/polyacrylamide(p(St-DVB)/pAM) particles were prepared by a two-step method. P(St-DVB) cores were firstly obtained via concentrated emulsion polymerization, and then the cores were swelled sufficiently and reacted with acrylamide until p(St-DVB)/pAM particles were obtain. The morphologies and compositions of p(St-DVB)/pAM particles were characterized by scanning electron microscopy(SEM) and infrared spectroscopy(IR) individually. It was proved that the micro-morphologies of p(St-DVB)/pAM particles were nearly spherical or even peanut shape. It was also found that the diameter distribution of p(St-DVB)/pAM particles became narrower with the increasing of DVB amounts, and the same trade was also observed on emulsifier amounts.

scholarly journals Self-Assembly Preparation of Nano-Lignin/Cationic Polyacrylamide Complexes

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1726
Author(s):  
Guoyu Tian ◽  
Xiuhong Zhong ◽  
Xuehai Wu ◽  
Zhaojiang Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Light Scattering ◽  
Self Assembly ◽  
Average Particle Size ◽  
Average Particle ◽  
Nano Particle ◽  
Enhanced Fluorescence ◽  
Scanning Electron

The present work describes the preparation of nano-lignin particles from calcium lignosulfonate (CL). The nano-lignin was fabricated from colloidal lignin–polyacrylamide complexes via self-assembly. The sizes of the nano-lignin particles were examined by dynamic light scattering (DLS) and scanning electron microscopy (SEM). The results indicated that the average particle size of the prepared nano-lignin was approximately 100 nm. In addition, the obtained nano-lignin exhibited enhanced fluorescence intensity when compared with the original lignin, which might represent a potential application of this nano-particle product.

Efficient improvement in non-enzymatic glucose detection induced by the hollow prism-like NiCo2S4 electrocatalyst

2021 ◽  
Author(s):  
Dandan Chu ◽  
Li Yan ◽  
Qiwen Chen ◽  
Xue-Qiang Chu ◽  
Danhua Ge ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Glucose Detection ◽  
X Ray Diffraction ◽  
Step Method ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

The hollow prism-like NiCo2S4 mateials (NiCo2S4 HNPs) were successfully fabricated by a two-step method. Scanning electron microscopy (SEM), transmission electron microscopy (TEM) and a powder X-ray diffraction (XRD) confirmed the...

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