Structural, thermal and mechanical properties of polymer nanocomposites based on organosoluble polyimide with naphthyl pendent group and layered double hydroxide

2016 ◽  
Vol 29 (8) ◽  
pp. 951-959 ◽  
Author(s):  
Mohammad Dinari ◽  
Ahmad Reza Rajabi
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Layered Double Hydroxide ◽  
In Situ Polymerization ◽  
Zinc Nitrate ◽  
Precipitation Reaction ◽  
Nitrate Hexahydrate ◽  
Pendent Group ◽  
Co Precipitation ◽  
Double Hydroxide

In this study, a soluble aromatic polyimide (PI) with naphthyl pendent group was initially synthesized by the reaction of pyromellitic dianhydride (PMDA) with 5-methyl- N,N-bis(4-nitrophenyl)naphthalen-1-amine. Then, via co-precipitation reaction of zinc nitrate hexahydrate and chromium nitrate nonahydrate, Zn/Cr-layered double hydroxide (LDH) was synthesized using hydrothermal techniques. Finally, different novel nanocomposites (NCs) based on PI and Zn/Cr-LDH (1, 2, 4 wt%) were produced through in situ polymerization. The resulting materials were characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, thermogravimetry analysis (TGA), field emission scanning electron microscopy, transmission electron microscopy, and mechanical testing. According to the TGA results, the prepared NCs showed high thermal stability at higher temperature due to the good dispersion and homogeneity of Zn/Cr-LDH in polymeric matrix. Consequently, the mechanical properties of the synthesized NCs were enhanced by the incorporation of 2 wt% Zn/Cr-LDH in the polymer matrix.

scholarly journals Pre-treatment of desalination feed seawater by Jordanian Tripoli, Pozzolana, and Feldspar: Batch experiments

2011 ◽  
Vol 17 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Aiman Al-Rawajfeh ◽  
Khaldoon Al-Whoosh ◽  
Dwairi Al ◽  
Ahmad Al-Maaberah ◽  
Amer Tarawneh
Keyword(s):  
Layered Double Hydroxide ◽  
Metal Ion ◽  
Raw Materials ◽  
Batch Experiments ◽  
Initial Concentration ◽  
Considerable Potential ◽  
Ion Concentrations ◽  
Pre Treatment ◽  
Co Precipitation ◽  
Double Hydroxide

In this research, composites of layered double hydroxide (LDH) with three Jordanian natural raw materials; Tripoli (T), Pozzolana (P) and Feldspar (F) were prepared by co-precipitation and have been used for feed seawater pre-treatment. The data reveals that percent adsorption decreased with increase in initial concentration, but the actual amount of adsorbed ions per unit mass of LDH/T-P-F increased with increase in metal ion concentrations. The values of ?Go were negative and within 21 to 26 KJ/mol, while the values of ?Ho and ?So were positive and within the range of 0.1 to 25 KJ/mol. The values of ?H?, ?S?, and ?G? indicate the favorability of physisorption and show that the LDH/T-P-F composites have a considerable potential as adsorbents for the removal of ions from seawater.

An elegant synthesis of chitosan grafted hydrotalcite nano-bio composite material and its effective catalysis for solvent-free synthesis of jasminaldehyde

RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 94562-94570 ◽  
Author(s):  
Jacky H. Adwani ◽  
Noor-ul H. Khan ◽  
Ram S. Shukla
Keyword(s):  
Composite Material ◽  
Layered Double Hydroxide ◽  
Solvent Free ◽  
Precipitation Method ◽  
Co Precipitation ◽  
Double Hydroxide ◽  
Solvent Free Synthesis

A novel nano-bio composite of chitosan and a layered double hydroxide elegantly synthesized by a co-precipitation method had effectively and selectively catalysed the jasminaldehyde synthesis.

scholarly journals In Situ Growth of ZnO Nanostructures on Cotton Fabric by Solochemical Process for Antibacterial Purposes

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
D. A. R. Souza ◽  
M. Gusatti ◽  
R. Z. Ternus ◽  
M. A. Fiori ◽  
H. G. Riella
Keyword(s):  
Electron Microscopy ◽  
Cotton Fabric ◽  
Zinc Nitrate ◽  
Nitrate Hexahydrate ◽  
Zno Nanostructures ◽  
In Situ Growth ◽  
Zinc Oxide Nanostructures ◽  
Gram Positive Bacteria ◽  
Transmission Electron

A practical and economical method was developed for the production of an antibacterial cotton fabric using zinc oxide nanostructures without the use of surface modifying agents. In this process, zinc nitrate hexahydrate and potassium hydroxide were used as starting materials and the reaction was performed at 50°C. The in situ growth of ZnO nanostructures on cotton fabric occurred in a single-stage process, and it started when the fabric samples were dipped for 1 min in the solution containing all the starting materials. The treated and untreated fabric samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and EDS. The cotton fabrics coated with ZnO nanostructures presented an antibacterial efficiency towards Pseudomonas aeruginosa, a gram-negative bacteria, and Staphylococcus aureus (S. aureus), a gram-positive bacteria.

Stabilization of Dicalcium Silicate-Zn Composite Approaching Layered Double Hydroxide Structure for Bioactive Cement Applications

2022 ◽  
Author(s):  
Hind Agourrame ◽  
Amine Belafhaili ◽  
Nisrine El Fami ◽  
Nacer Khachani ◽  
Mohamed Alami Talbi ◽  
...  
Keyword(s):  
Acid Solution ◽  
Layered Double Hydroxide ◽  
S Phase ◽  
Dicalcium Silicate ◽  
Metal Salts ◽  
Basic Solution ◽  
Silicate Phase ◽  
Edax Analysis ◽  
Co Precipitation ◽  
Double Hydroxide

Layered Double Hydroxide (LDH) is ionic clay that is characterized by the union of metal cations and OH- hydroxides. LDH composites exhibit considerably high releasing and recharging capacity and have applications as bioactive cements. They can be prepared by direct co-precipitation of metal salts at controlled pH. The preparation is carried out from an acid solution of Zn (NO3)2.6H2O, Al (NO3)3.9H2O and a basic solution of Na2CO3 and NaOH, with a Zn/Al ratio = 3, the pH is stabilized between 9 and 9.5 at a constant temperature of 45°C. The objective of this study is to incorporate Zinc and Aluminum elements at different percentages in dicalcium silicate phase to produce C2S phase incorporating LDH composite. The characterizations of the developed phases by XRD and SEM indicate the formation of stoichiometric LDH phases Zn6Al2(OH)16CO3.4H2O and non-stoichiometric Zn0.61Al0.39 (OH)2(CO3)0.195.xH2O, the incorporation of Zn in the belitic C2S phase and not Al. The obtained micrographs by SEM(EDAX) analysis show new morphology of the stabilized composite.

Two-different ways of synthesis for EG: Study of mechanical, thermal, and electrical properties of epoxy composite for TIMs

2020 ◽  
pp. 095400832094538
Author(s):  
Sagar Kumar Nayak ◽  
Arjyama Mishra ◽  
Subhransu S Pradhan ◽  
Jyoti Agarwal
Keyword(s):  
Electron Microscopy ◽  
Epoxy Composite ◽  
Expanded Graphite ◽  
Ammonium Persulfate ◽  
Zinc Nitrate ◽  
Electrochemical Process ◽  
Graphite Flake ◽  
Nitrate Hexahydrate ◽  
Transmission Electron ◽  
Inverse Rule

The current study reports the synthesis of expanded graphite (EG) in two different ways and its fabrication with epoxy matrix to form composite at various filler fractions (5, 10, 12.5). One type EG (EG-C) is prepared by the electrochemical process using natural graphite flake (NGF), concentrated sulfuric acid, and ammonium persulfate, while the other (EG-P) is just mixing and heating of NGF with zinc nitrate hexahydrate. The functional groups of synthesized EG were confirmed by Fourier transform infrared spectroscopy. The surface morphology and microstructure of synthesized filler (EG-C, EG-P) were studied using X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. An optimum through-plane thermal conductivity (TC) of 2.04 and 2.22 W/mK was observed in the case of the composites containing 12.5 wt% of EG-C and EG-P, respectively. The obtained experimental TC was compared with three numerical thermal models, that is, inverse rule of mixture, Maxwell–Eucken model, and Agari model. Furthermore, the thermal stability of both composites was compared by using a thermogravimetric analyzer. The electrical resistivity of EG-P/epoxy composite at different formulations was higher than the EG-C-filled epoxy composites.

Cu/Al Layered Double Hydroxide by Co-precipitation with High Anti-UV Performance in Waterborne Varnish

2019 ◽  
Vol 48 (8) ◽  
pp. 866-869
Author(s):  
Xiuxiu Han ◽  
Shuhua Zhang ◽  
Jingjing Lu ◽  
Yingying Ma ◽  
Nengshuo Fu ◽  
...  
Keyword(s):  
Layered Double Hydroxide ◽  
Co Precipitation ◽  
Double Hydroxide

Thermal and rheological properties of polyamide 6/layered double hydroxide clay composites

2019 ◽  
Vol 27 (9) ◽  
pp. 567-581 ◽  
Author(s):  
RDS Zwane ◽  
ER Sadiku ◽  
SS Ray ◽  
NE Luruli
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Rheological Properties ◽  
Layered Double Hydroxide ◽  
Polyamide 6 ◽  
Negative Influence ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Double Hydroxide ◽  
Nucleating Effect

Thermal and rheological properties of polyamide 6/layered double hydroxide (PA6/LDH) composites were studied. Pristine (U-LDH) and organically modified (M-LDH) clays were used in this study. Some evidence of intercalation was observed on the microstructure of PA6/M-LDH samples, while PA6/U-LDH was characterised by microcomposite morphology as shown by the transmission electron microscopy results. The scanning electron microscopy results showed a complete delamination of the M-LDH in the PA6 matrix while U-LDH was evenly dispersed as immiscible tactoids. In the melt state, the M-LDH had a significant influence on the melt microstructure of PA6 matrix when compared to U-LDH. Differential scanning calorimetry results, both dynamic and isothermal experiments, showed that LDH had a heterogeneous nucleating effect on the PA6 matrix, with the U-LDH showing better nucleating effect when compared to M-LDH. The thermogravimetric analysis results showed that M-LDH had a negative influence on the thermal stability of the composites, while U-LDH improved their thermal stability. The X-ray diffraction and dynamic mechanical analysis results showed that the presence of M-LDH promoted the formation of γ-crystallites in the PA6 matrix, while U-LDH composites were dominated by the α-crystallites. This phenomenon had a positive correlation with increasing content of both LDH clays. An overall improved dynamic mechanical properties were observed for PA6/U-LDH when compared to PA6/M-LDH composites.

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