scholarly journals Exploring the difference in xerogels and organogels through in situ observation

2018 ◽  
Vol 5 (1) ◽  
pp. 170492
Author(s):  
Binglian Bai ◽  
Zhiming Li ◽  
Haitao Wang ◽  
Min Li ◽  
Yukihiro Ozaki ◽  
...  
Keyword(s):  
Liquid Crystalline ◽  
Fluorescence Spectra ◽  
Chemical Properties ◽  
Columnar Structure ◽  
In Situ Observation ◽  
Physico Chemical ◽  
Aggregation Structure ◽  
Ft Ir ◽  
The Difference

Solvent–gelator interactions play a key role in mediating organogel formation and ultimately determine the physico-chemical properties of the organogels and xerogels. The ethanol organogels of 1,4-bis[(3,4,5-trihexyloxy phenyl)hydrazide]phenylene (TC6) were investigated in situ by FT-IR, Raman and fluorescence spectra, and XRD, and it was confirmed that the intermolecular interaction and aggregation structure of TC6 ethanol organogels were quite different from those of xerogels. Simultaneously, unprecedented phase transition from organogel to suspension upon heating was observed in ethanol organogel, and the suspension phase exhibited lytropic liquid crystalline behaviour with a rectangular columnar structure. This study may open the possibility to design new gelators with a new dimension of versatility.

In situ dual crosslinking strategy to improve the physico-chemical properties of thermoplastic starch

2021 ◽  
pp. 118250
Author(s):  
Hamed Peidayesh ◽  
Abolfazl Heydari ◽  
Katarína Mosnáčková ◽  
Ivan Chodák
Keyword(s):  
Chemical Properties ◽  
Thermoplastic Starch ◽  
Physico Chemical

scholarly journals Soil physico-chemical characterization in the different soil layers of National Maize Research Program, Rampur, Chitwan, Nepal

2018 ◽  
Vol 3 (1) ◽  
pp. 28-44
Author(s):  
Dinesh Khadka ◽  
Sushil Lamichhane ◽  
Amit P Timilsina ◽  
Bandhu R Baral ◽  
Kamal Sah ◽  
...  
Keyword(s):  
Research Program ◽  
Soil Structure ◽  
Sandy Loam ◽  
Chemical Properties ◽  
Single Layer ◽  
Chemical Characterization ◽  
Bottom Layer ◽  
Soil Parameters ◽  
Physico Chemical

Soil pit digging and their precise study is a decision making tool to assess history and future of soil management of a particular area. Thus, the present study was carried out to differentiate soil physico-chemical properties in the different layers of excavated pit of the National Maize Research Program, Rampur, Chitwan, Nepal. Eight pits were dug randomly from three blocks at a depth of 0 to 100 cm. The soil parameters were determined in-situ, and in laboratory for texture, pH, OM, N, P (as P2O5), K (as K2O), Ca, Mg, S, B, Fe, Zn, Cu and Mn of collected soils samples of different layers following standard analytical methods at Soil Science Division, Khumaltar. The result revealed that soil structure was sub-angular in majority of the layers, whereas bottom layer was single grained. The value and chrome of colour was increasing in order from surface to bottom in the majority pits. Similarly, the texture was sandy loam in majority layers of the pits. Moreover, four types of consistence (loose to firm) were observed. Furthermore, mottles and gravels were absent in the majority layers. Likewise, soil was very to moderately acidic in observed layers of majority pits, except bottom layer of agronomy block was slightly acidic. Regarding fertility parameters (OM, macro and micronutrients), some were increasing and vice-versa, while others were intermittent also. Therefore, a single layer is not dominant for particular soil physico-chemical parameters in the farm. In overall, surface layer is more fertile than rest of the layers in all the pits.     

scholarly journals In situ sol-gel synthesis of hyaluronan derivatives bio-nanocomposite hydrogels

2019 ◽  
Vol 6 (5) ◽  
pp. 249-258 ◽  
Author(s):  
U D’Amora ◽  
A Ronca ◽  
M G Raucci ◽  
S M Dozio ◽  
H Lin ◽  
...  
Keyword(s):  
Sol Gel ◽  
Chemical Properties ◽  
Filler Concentration ◽  
Similar Degree ◽  
Nanocomposite Hydrogels ◽  
Physico Chemical ◽  
Inorganic Fillers ◽  
Sol Gel Synthesis ◽  
Physical Blending

Abstract The main driving idea of the present study was the comparison between two different chemical modifications of hyaluronic acid (HA) followed by the development of nanocomposite hydrogels directly in situ by biomineralization of photocrosslinkable HA polymers through sol-gel synthesis. In this way, it has been possible to overcome some limitations due to classical approaches based on the physical blending of inorganic fillers into polymer matrix. To this aim, methacrylated and maleated HA, synthesized with similar degree of substitution (DS) were compared in terms of mechanical and physico-chemical properties. The success of in situ biomineralization was highlighted by reflect Fourier transform infrared spectroscopy and thermogravimetric analysis. Furthermore, mechanical characterization demonstrated the reinforcing effect of inorganic fillers evidencing a strong correlation with DS. The swelling behavior resulted to be correlated with filler concentration. Finally, the cytotoxicity tests revealed the absence of toxic components and an increase of cell proliferation over culture time was observed, highlighting these bio-nanocomposite hyaluronan derivatives as biocompatible hydrogel with tunable properties.

Autoclave-assisted green synthesis of silver nanoparticles using A. fumigatus mycelia extract and the evaluation of their physico-chemical properties and antibacterial activity

2018 ◽  
Vol 7 (3) ◽  
pp. 217-224 ◽  
Author(s):  
Sarah Ghanbari ◽  
Hamideh Vaghari ◽  
Zahra Sayyar ◽  
Mohammad Adibpour ◽  
Hoda Jafarizadeh-Malmiri
Keyword(s):  
Particle Size ◽  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Chemical Properties ◽  
Heating Time ◽  
Gram Negative Bacteria ◽  
Synthesis Conditions ◽  
High Antibacterial Activity ◽  
Physico Chemical ◽  
Ft Ir

Abstract Silver nanoparticles (AgNPs) were synthesized using Aspergillus fumigatus (A. fumigatus) mycelia extract via the hydrothermal method. The main reducing and stabilizing groups and components of A. fumigatus extract, such as amine, hydroxyl, amid, protein, enzymes, and cell saccharide compounds, were identified by Fourier transform infrared (FT-IR). Central composition design was used to plan the experiments, and response surface methodology was applied to evaluate of the effects of independent variables, including the amount of the prepared extract (5–7 ml) and heating time (10–20 min) at 121°C and 1.5 bar), on the particle size of the synthesized AgNPs, as manifested in broad emission peak (λmax). More stable and spherical monodispersed AgNPs, with mean particle size, polydispersity index (PDI) value, and maximum ζ potential value of 23 nm, 0.270, and +35.3 mV, respectively, were obtained at the optimal synthesis conditions using 7 ml of A. fumigatus extract and heating time of 20 min. The synthesized AgNPs indicated high antibacterial activity against both Gram-positive and Gram-negative bacteria.

scholarly journals Preparation and of PVA-based compositions with embedded silver, copper and zinc oxide nanoparticles and assessment of their antibacterial properties

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Jolanta Pulit-Prociak ◽  
Anita Staroń ◽  
Paweł Staroń ◽  
Anna Chmielowiec-Korzeniowska ◽  
Agata Drabik ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Metallic Nanoparticles ◽  
Antibacterial Properties ◽  
Chemical Properties ◽  
Microscopic Analysis ◽  
Poly Vinyl Alcohol ◽  
Physico Chemical ◽  
Dynamic Light Scattering Technique ◽  
Ft Ir ◽  
Bacterial Film

Abstract A series of poly(vinyl alcohol) (PVA) based liquid compositions with addition of zinc oxide, silver and copper nanoparticles has been prepared. The compositions also contained other consistency-forming organic components. The physico-chemical properties of the products have been determined. Their pH and density have been assessed. Also, the size of nanoparticles has been defined with using a dynamic light scattering technique. The compositions were subjected to XRD, FT-IR and microscopic analysis as well. Thanks to the incorporation of both metal oxide and metallic nanoparticles, it was possible to enrich the products with antibacterial properties. Their inhibiting properties in the growth of microorganisms have been confirmed against both Gram-negative and Gram-positive strains such as E. coli, S. aureus and P. aeruginosa. Thanks to the ability for solidification, the compositions may be applied on a bacterially contaminated surface, and after destroying the microorganisms and its solidification, it may be peeled off along with the dead bacterial film.

Structural and Photocatalytic Property of CaTiO3 Nanosphere

2020 ◽  
Vol 979 ◽  
pp. 169-174 ◽  
Author(s):  
C. Karthikeyan ◽  
M. Thamima ◽  
S. Karuppuchamy
Keyword(s):  
Dye Degradation ◽  
Uv Light ◽  
Chemical Properties ◽  
Photocatalytic Property ◽  
Advanced Characterization ◽  
Morphological Studies ◽  
Physico Chemical ◽  
Raman Study ◽  
Ft Ir ◽  
Xrd Patterns

The nanostructured photocatalysts are the most promising materials for the degradation of toxic dyes. Particularly, CaTiO3 has been used in several applications including catalytic, optical, biological and electronic. In this present study, perovskite structured CaTiO3 nanomaterials have been synthesized by microwave irradiation method. The physico-chemical properties of the prepared CaTiO3 nanomaterials were studied by various advanced characterization techniques. The XRD patterns confirm the presence of perovskite structure of the prepared nanomaterials. FT-IR analysis confirms the presence of Ca-Ti-O vibrational bonds. Micro Raman study display the existence of O-Ca-Ti-O with B1g mode of vibrations. Morphological studies revealed the presence of truncated nanospheres. The dye degradation property of prepared CaTiO3 was investigated by Malachite green (MG) by UV-light.

Influence of Copolymer Architecture on Generation of Defects in Reactive Multilayer Coextrusion

2015 ◽  
Vol 651-653 ◽  
pp. 836-841 ◽  
Author(s):  
Arnaud Bondon ◽  
Khalid Lamnawar ◽  
Abderrahim Maazouz
Keyword(s):  
Chemical Properties ◽  
Polyamide 6 ◽  
Interface Roughness ◽  
Interfacial Instabilities ◽  
Influence Of Process Parameters ◽  
Ethylene Vinyl Alcohol ◽  
Barrier Layers ◽  
Interfacial Morphology ◽  
Physico Chemical

Several polymers can be combined in one multilayer structure by reactive coextrusion. Tie-layers are often used to compatibilize adjacent layers and may reduce or suppress interfacial instabilities and defects in multilayer coextrusion flow. However, a new additional defect defined as “grainy” defect can be observed. In our best of knowledge, no study in literature has been dedicated to understand its origin. The phenomena are quite complex due to the coupling of the effects of flow and the physico-chemical mechanisms at the interface. The aim of this work is to understand the relationship between the instabilities and defects encountered in multilayer coextruded films and the role of the copolymer formed in-situ between tie and barrier layers. Polyamide 6 (PA6) and ethylene-vinyl alcohol copolymer (EVOH) were used as barrier layers sandwiched in polypropylene (PP) with or without tie-layer based on polypropylene grafted maleic anhydride (PP-g-MA). Influence of process parameters and nature of the polymer pair on the generation of “grainy” defect has been assessed and related to the rheological and the physico-chemical properties of layers. These experiments showed that this defect appeared mainly in the compatibilized EVOH system and could be distinguished from the usual coextrusion instabilities. Interfacial properties between tie and barrier layers have been investigated. Shear stress relaxation experiments have been carried out on reactive tie/barrier bilayers. Due to the interphase generated in-situ, the relaxation behavior was altered by extending the relaxation time. Investigation of interfacial morphology highlighted that the copolymer architecture significantly affected the interface/interphase development and interface roughness. Hence, relationships between relaxation process, interfacial morphology and copolymer structure were correlated with the generation of grainy defects in coextrusion.

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