scholarly journals Hydrophobic and Flame-Retardant Foam Based on Cellulose

2021 ◽  
Author(s):  
Amal H. Abdel Kader ◽  
sawsan Dacrory ◽  
Tawfik A. Khattab ◽  
samir kamel ◽  
Hussein Abou-Yousef
Keyword(s):  
Chemical Structure ◽  
Freeze Drying ◽  
Fire Retardant ◽  
Spray Coating ◽  
Drying Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Flammability Test ◽  
Flammability Characteristics ◽  
Scanning Electron

Abstract A series of lightweight, hydrophobic, and fire retardant foams were fabricated through activation of cellulose by phosphoric acid as a primarily step. Dolomite clay was embedded onto the cellulosic suspensions with gelatin/ tannin as adhesive followed by freeze drying process. A solution of the environmentally friendly silicone rubber (RTV) was applied onto foam samples via spray-coating to improve their water repealing performance, which was explored by investigating both of water contacting angle and wettability time of the coated foam samples. Flammability characteristics, thermal decomposition, surface morphology, and chemical structure of treated and untreated foams were investigated by flammability test, thermogravimetric analysis, scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared, respectively. Results showed that the foams loaded dolomite and coated RTV have high hydrophobicity as well as anti-inflammability.

Corrosion Behavior of Q235A Steel under Wet-Dry Cyclic Condition

2012 ◽  
Vol 557-559 ◽  
pp. 139-142
Author(s):  
Jian Guo Liu ◽  
Yan Tao Li ◽  
Bao Rong Hou
Keyword(s):  
Electron Microscopy ◽  
Chloride Concentration ◽  
Corrosion Products ◽  
Drying Process ◽  
X Ray Diffraction ◽  
Cathodic Process ◽  
X Ray ◽  
Reduction Processes ◽  
Cyclic Condition ◽  
Scanning Electron

The corrosion processes and mechanisms of Q235A steel under wet-dry cyclic condition were studied using polarization curve compared with immersion samples, while, the corrosion morphologies and corrosion products of the steel samples were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The cathodic process of wet-dry samples was likely to be controlled not by the oxygen reduction, but rather by the reduction of corrosion products. During the drying process of the wet-dry sample, the electrolyte thickness decreased and chloride concentration increased. Oxygen would be much easier to diffuse into the interface of electrolyte/metal, which improved the cathodic reduction processes. Except for this, the rust itself took part in the reduction processes and hence increased the corrosion rate of the steel samples.

scholarly journals Preparation of BaZrO3 powders by a spray-drying process

2003 ◽  
Vol 18 (6) ◽  
pp. 1325-1332 ◽  
Author(s):  
B. Robertz ◽  
F. Boschini ◽  
A. Rulmont ◽  
R. Cloots ◽  
I. Vandriessche ◽  
...  
Keyword(s):  
Spray Drying ◽  
Precursor Solution ◽  
Barium Zirconate ◽  
Drying Process ◽  
X Ray Diffraction ◽  
High Quality ◽  
Corrosion Resistant ◽  
X Ray ◽  
Potential Use ◽  
Scanning Electron

The potential use of barium zirconate for the manufacture of corrosion-resistant substrates emphasizes the need for a simple, inexpensive, and easily scalable process to produce high-quality powders with well-controlled composition and properties. However, the classical solid-state preparation of barium zirconate leads to an inhomogeneous powder unsuitable for applications in highly corrosive environment. For this paper, the possibility to use the spray-drying technique for the preparation of BaZrO3 powders with a controlled size distribution and morphology was investigated. The influence of the nature and concentration of the precursor solution and the influence of the spray-drying step are discussed on the basis of x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and dilatometric measurements.

Effect of Processing Conditions on Properties of KMnO4-Treated PAN Fibers

2013 ◽  
Vol 821-822 ◽  
pp. 23-27
Author(s):  
Xiang Li ◽  
Chun Yi Liu ◽  
Ai Wen Qin ◽  
Xin Zhen Zhao ◽  
Chun Ju He
Keyword(s):  
Mechanical Properties ◽  
Aqueous Solution ◽  
Chemical Structure ◽  
Suitable Condition ◽  
Wide Angle ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron ◽  
Pan Fibers

Plasticized polyacrylonitrile(PAN) fibers have been chemically impregnated with aqueous solution of KMnO4under varying conditions of temperature and time. The effect of modification conditions on the chemical structure and the mechanical properties of precursor fibers are characterized by wide-angle X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscope. The experimental results show that KMnO4can be used not only as catalyst for cyclization reaction, but also as plasticizer. The chemical modification between KMnO4and PAN can not occur below70°C, the most suitable condition for modification is performed at 80°C for 5 min.

scholarly journals Synthesis of Nanocrystalline Mg-Al Hydrotalcites in the Presence of Starch—the Effect on Structure and Composition

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 602
Author(s):  
Alicja Michalik ◽  
Bogna D. Napruszewska ◽  
Anna Walczyk ◽  
Joanna Kryściak-Czerwenka ◽  
Dorota Duraczyńska ◽  
...  
Keyword(s):  
Freeze Drying ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthesis Parameters ◽  
All Solutions ◽  
Co Precipitation ◽  
Starch Potato ◽  
Degree Of Order ◽  
Scanning Electron

The study describes the synthesis of Mg-Al hydrotalcite (Ht) with the use of starch as a structure controlling biotemplate. Syntheses were carried out at room temperature, by co-precipitation at pH = 10. The investigated synthesis parameters included the nature of the precipitating agent (NaOH/Na2CO3 or NH3aq/(NH4)2CO3), the nature of starch (potato, corn and cassava), the method of starch addition to reagents, the method of drying and the effect of washing. The materials were examined with X-ray diffraction, scanning electron microscopy/energy dispersive X-ray spectroscopy and infrared spectroscopy. The data show that synthesis of Ht materials in the presence of starch, with use of the ammonia-based precipitant, enabled preparation of nanocrystalline Ht with very fine (<50 nm) particle size. All investigated starches had a similar effect on the crystallinity and the grain size of Ht precipitates. Ht with the smallest nanocrystals was obtained when starch was present in all solutions used for synthesis, and the final product subjected to freeze drying. Washing with water was found to enhance recrystallization and exchange of nitrates for carbonates. Infrared spectra showed that an interaction exists between the biopolymer template and the Ht particles, resulting in a higher degree of order within the Ht-adhering starch component.

scholarly journals Effect of H2O Activity on Zeolite Formation

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4780
Author(s):  
Claudia Belviso ◽  
Francesco Cavalcante
Keyword(s):  
Liquid Nitrogen ◽  
Sodium Aluminate ◽  
Drying Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lta Zeolite ◽  
Zeolite Formation ◽  
Silica Alumina ◽  
Over Time ◽  
Scanning Electron

In an effort to understand the effects of H2O activity on zeolite formation, we have synthesized LTA zeolite using a combination of freezing processes and varying drying temperatures. Sodium aluminate and sodium silicate were used to form LTA zeolite, according to the IZA (International Zeolite Association) protocol. The synthesis steps were modified by adding the precursor frozen process by a rapid liquid nitrogen (−196 °C) treatment or slow conventional freezer treatment (−20 °C). The samples were subsequently sonicated and then dried at 80 °C or 40 °C. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed on the samples immediately after the drying process as well as after 2 weeks and 1 month of aging the solid products. The results indicated that LTA zeolite does not form. The silica-alumina precursor after both freezing processes and after being dried at 80 °C showed the presence of sodalite displaying stable behavior over time. Both sets of samples dried at 40 °C and did not show the presence of zeolite immediately after the drying process. However, after 2 weeks, the liquid nitrogen–frozen precursor was characterized by the presence of EMT whereas zeolites never formed in the −20 °C samples. These results suggest that freezing processes differently control the H2O activity during the drying and aging processes in the solid state. Thus, although the precursor chemical composition is the same, the type of zeolite formed is different.

scholarly journals ENHANCEMENT OF LORNOXICAM SOLUBILITY BY INCLUSION COMPLEXATION WITH CYCLODEXTRIN: PREPARATION AND CHARACTERIZATION

2016 ◽  
Vol 9 (1) ◽  
pp. 132 ◽  
Author(s):  
Shahira Fawzy El-menshawe ◽  
Essam Eissa ◽  
Adel A. Ali ◽  
Ahmed A. Abderhman
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Inclusion Complexation ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Physical Mixing ◽  
Solid Complexes ◽  
Scanning Electron

<p><strong>Objective: </strong>Lornoxicam is a potent anti-inflammatory drug which has analgesic and antipyretic properties. It is water-insoluble powder. The inclusion complexes of lornoxicam (LOR) with β-cyclodextrin (βCD) and 2-hydroxypropyl-β-cyclodextrin (HPCD) were prepared and characterised in order to improve the solubility of the drug and enhance its bioavailability.</p><p><strong>Methods: </strong>Complexes were prepared by physical mixing and freeze-drying in three different drug/polymer ratios (1:1, 1:2 and 3:2). The solid complexes were characterised through differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray diffraction, nuclear magnetic resonance (NMR) spectroscopy, and Fourier transformed infrared (FTIR) spectroscopy.</p><p><strong>Results: </strong>The data showed that LOR may be complexed with cyclodextrin (CD) forming soluble complexes. The lyophilized 1:2 LOR/HPCD complex is the most soluble.</p><p><strong>Conclusion: </strong>Solubility increases with lyophilization than with physical mixing and by the use of HPCD than βCD in complexation.</p>

scholarly journals Influence of Strong Acid Hydrolysis Processing on the Thermal Stability and Crystallinity of Cellulose Isolated from Wheat Straw

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Chemar J. Huntley ◽  
Kristy D. Crews ◽  
Mohamed A. Abdalla ◽  
Albert E. Russell ◽  
Michael L. Curry
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Acid Hydrolysis ◽  
Wheat Straw ◽  
Cellulose Fibers ◽  
Drying Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Cellulose extractions from wheat straw via hydrochloric, nitric, and sulfuric acid hydrolysis methods were carried out. X-ray diffraction spectral analyses reveal that depending on the acid conditions used the structure of the cellulose exhibited a mixture of polymorphs (i.e., CI and CIII cellulose phases). In addition, the percent crystallinity, diameter, and length of the cellulose fibers varied tremendously as determined by X-ray diffraction and scanning electron microscopy. Thermal gravimetric analysis measurements revealed that the thermal stability of the extracted cellulose varied as a function of the acid strength and conditions used. Scanning electron microscopy analysis revealed that the aggregation of cellulose fibers during the drying process is strongly dependent upon the drying process and strength of the acids used.

scholarly journals Sustainable Functionalization of PAN to Improve Tinctorial Capacity

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3665
Author(s):  
Vasilica Popescu ◽  
Ingrid Ioana Buciscanu ◽  
Melinda Pruneanu ◽  
Stelian Sergiu Maier ◽  
Angela Danila ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Xrd Analysis ◽  
Hypervalent Iodine ◽  
X Ray Diffraction ◽  
X Ray ◽  
Yellow Orange ◽  
The Fourier Transform ◽  
Scanning Electron ◽  
Pan Fibers

This study may open a new way to obtain the coloration of a polymer during functionalization. Two polyacrylonitrile (PAN) polymers in the form of textile fibers (Melana and Dralon L) were subjected to functionalization treatments in order to improve the dyeing capacity. The functionalizations determined by an organo-hypervalent iodine reagent developed in situ led to fiber coloration without using dyes. KIO3 was formed in situ from the interaction of aqueous solutions of 3–9% KOH with 3–9% I2, at 120 °C. The yellow-orange coloration appeared as a result of the transformations in the chemical structure of each functionalized polymer, with the formation of iodinehydrin groups. The degree of functionalization directly influenced the obtained color. The results of the Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), Map and Temogravimetric Analysis (TG) plus Differential Thermal (DTA) analyses indicated the presence of new functional groups, such as iodine-oxime. The X-ray diffraction (XRD) analysis confirmed the change of the crystalline/amorphous ratio in favor of the former. The new groups introduced by functionalization make it possible to dye with classes of dyes specific to these groups, but not specific to PAN fibers, thus improving their dyeing capacity.

Microtructure of Woodceramics Modified By Enzymatic Hydrolysis Lignin

2011 ◽  
Vol 236-238 ◽  
pp. 486-489
Author(s):  
Zhen Kun Huang ◽  
Xiao Xiao Zhao ◽  
Qiu Feng Lü ◽  
Xian Su Cheng
Keyword(s):  
Enzymatic Hydrolysis ◽  
Chemical Structure ◽  
Phenolic Resin ◽  
Phase Identification ◽  
Hydrolysis Lignin ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Phase ◽  
Ft Ir ◽  
Scanning Electron

Novel woodceramics were fabricated by camphora powder and phenolic resin modified by enzymatic hydrolysis lignin (EHL). The chemical structure, phase identification and morphology of woodceramics were investigated by FT-IR, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that woodceramics possessed topologically homogenous structure and contained C-O-C, C–H and C =C bonds. EHL played an important role upon the microstructures of woodceramics. The disorder of woodceramics was reduced while content of EHL was increased.

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