scholarly journals Effect of Different Aluminum Substitution Rates on the Structure of Tobermorite

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3765
Author(s):  
Liao ◽  
Li ◽  
Fang ◽  
Lu ◽  
Xu
Keyword(s):  
Exothermic Peak ◽  
Mas Nmr ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Al Substitution ◽  
27Al Mas Nmr ◽  
Substitution Ratio ◽  
Ft Ir ◽  
Repulsive Forces ◽  
Aluminum Substitution

Tobermorite and Al-substituted tobermorite with varying Al/(Si + Al) molar ratios were synthesized via the static hydrothermal method. The effect of different Al substitution ratios on the structure of tobermorite was investigated by XRD, SEM–EDS, TG–DSC, FT–IR, 29Si, and 27Al MAS–NMR. The interplanar crystal spacing of (002) increased with the increment of the Al substitution ratio. The maximum ratio of the Al substitution for Si in the structure of tobermorite was about 15 at %, which was limited by the compositions of tobermorite and the electrostatic repulsive forces caused by Al substitution. The DSC curve of the tobermorite with an Al/(Al + Si) molar ratio of 0.15 showed a larger exothermic peak area at 850 °C, indicating that the Al-O-Si bond was formed in the structure of tobermorite and the Al participated in the recrystallization. The 29Si and 27Al MAS–NMR results confirmed that tetrahedral Al was introduced into the structure of the tobermorite. New silicon sites, Q2(1Al) and Q3(1Al), formed by the Al substitution for Si in bridging and non-bridging sites, were detected. Compared to the tobermorite without Al substitution, the adsorption capacity of Al-substituted tobermorite with Al/(Al + Si) = 0.15 to Na+ was improved by 44%.

THE USE OF THE COMBINATION OF FTIR, PYRIDINE ADSORPTION, 27Al AND 29Si MAS NMR TO DETERMINE THE BRÖNSTED AND LEWIS ACIDIC SITES

2016 ◽  
Vol 78 (6) ◽  
Author(s):  
Djoko Hartanto ◽  
Lai Sin Yuan ◽  
Sestriana Mutia Sari ◽  
Djarot Sugiarso ◽  
Irmina Kris Murwarni ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Aluminum Atom ◽  
Xrd Analysis ◽  
Acid Sites ◽  
Mas Nmr ◽  
Molar Ratio ◽  
Pyridine Adsorption ◽  
Lewis Acid Sites ◽  
27Al Mas Nmr ◽  
Pre Treatment

Lewis and Brönsted acidity were studied on ZSM-5 with combination of pyridine adsorption and FTIR vibration, ZSM-5 synthesized using kaolin Bangka Indonesia with an increase in the molar ratio of Si/Al 30-60 without pre-treatment and without organic templates and with seeds silicalite. Interestingly, the intensity of the infrared showed an increase of band vibration pyridine as absorbed Brönsted and Lewis acid sites in a molar ratio increase of Si/Al in ZSM-5, indicating an increase in the number of silanol (Brönsted acid) and deformed silica (Lewis acid) because the amount of Aluminum in ZSM-5 decrease with increase Si/Al but amount acidity increase. 29Si and 27Al MAS NMR analysis was supported by the results of infrared to indicate that all of the aluminum atom is coordinated with their neighbors are the same in ordering the ZSM-5 framework and 27Al MAS NMR showed a sharp peak of all the variations of Si/Al except the Si/Al 30 shows a low peak area. XRD analysis supported that the ZSM-5 structure formed is pure and crystal and a decrease in crystallinity proven for more than Si/Al 50, that defects silica occurs in ZSM-5, this corresponds to the growing number of Lewis acid sites caused by defects silica described the infrared results.

Bio-oil as Substitute of Phenol for Synthesis of Resol-type Phenolic Resin as Wood Adhesive

2017 ◽  
Vol 16 (3) ◽  
Author(s):  
Fangjia Dong ◽  
Mingcun Wang ◽  
Zhehui Wang
Keyword(s):  
Weight Ratio ◽  
Wood Adhesive ◽  
Exothermic Peak ◽  
Molar Ratio ◽  
Type I ◽  
Thermal Cure ◽  
Molar Ratios ◽  
Comprehensive Properties ◽  
Bio Oil ◽  
Resol Resin

AbstractThe bio-oil from fast pyrolysis of cornstalks was used as substitute of phenol to synthesize resol resin as an ideal wood adhesive. The effects of formaldehyde/phenol (F/P) molar ratios and oil/phenol (O/P) weight ratios on rehology, thermal cure, thermal resistance and adhension of plywoods were investigated. With the increase of bio-oil used in bio-resol, the gel time of the prepared bio-oil modified resol resin (bio-resol resin) increased gradually, and the exothermic peak temperature of thermal cure shifted slightly higher. It was found that the bio-resin with bio-oil/phenol = 0.5 (weight ratio) and F/P = 1.5 (molar ratio) had the best comprehensive properties. The plywoods made with the bio-resol resins fulfilled the standards of E0and type I plywood, implying the bio-resol resins was a new environment-friendly adhesive.

Synthesis and Characterisation of P-perfluoro{-1-[2-(2-fluorosulfonylethoxy) Propoxy]}Ethylated Polystyrene

2005 ◽  
Vol 2005 (8) ◽  
pp. 546-548
Author(s):  
Ji-Cheng Yang ◽  
Hong-Bo Ni ◽  
Jin Li ◽  
Cheng-Xue Zhao ◽  
Yong-Ming Zhang
Keyword(s):  
Thermogravimetric Analysis ◽  
Contact Angles ◽  
Molar Ratio ◽  
Ethyl Group ◽  
Molar Ratios ◽  
Modified Polymer ◽  
Ft Ir

A new kind of fluorinated polystyrene bearing a p-perfluoro{-1-[2-(2-fluorosulfonyl)propoxy]}ethyl group has been synthesised by one-electron oxidation of polystyrene by perfluoro{2-[2-(2-fluorosulfonyl) propoxy]}propionyl peroxide at different peroxide to polystyrene molar ratios. The yield of ω–fluorosulfonyl perfluoroalkylation decreases with increase in the reactant molar ratio. The modified polymer was characterised by various techniques: the ring perfluoro{-1-[2-(2-fluorosulfonyl)propoxy]}ethylation was proved by FT-IR, 19F NMR and DSC; desulfonylation of the fluorinated polystyrene appearing at 126° has been found by thermogravimetric analysis (TGA). The contact angles of water on the surface of ω–fluorosulfonyl perfluoroalkylated polystyrene were determined.

scholarly journals Synthesis of Layered Octadecyltrimethylammonium-Templated Aluminosilicate and its Use as a Thickening Agentfor Lubricating Grease

2021 ◽  
Author(s):  
Lukun Han ◽  
Wenxing Niu ◽  
Xinrui Zhao ◽  
Hong Xu ◽  
Jinxiang Dong
Keyword(s):  
Molar Ratio ◽  
Wear Property ◽  
X Ray Diffraction ◽  
Lubricating Grease ◽  
X Ray ◽  
Molar Ratios ◽  
Simple Preparation ◽  
Dropping Point ◽  
27Al Mas Nmr ◽  
Aluminum Silicon

Abstract We describe herein the use of octadecyltrimethylammonium-templated aluminosilicate (designated as LS) as a thickener to induce gelation. LS samples with different aluminum/silicon molar ratios (Al/Si = 0, 0.05, 0.10, 0.15, 0.20) were synthesized hydrothermally and characterized by X-ray diffraction analysis, 27Al MAS NMR spectra, elemental analysis, and scanning electron microscopy. The aluminum/silicon molar ratio was shown to be an important factor affecting the rheological properties of LS gels. With increasing Al/Si molar ratio, the viscoelasticity and structural strength of LS gel were enhanced, the dropping point increased, and the amount of oil separation decreased. LS(0.20) gel exhibited superior relative elastic character. The strength of the LS(0.20) gel was also enhanced with increasing LS(0.20) content. In SRV tests, LS(0.20) gel with different contents showed good performance in terms of load-bearing ability and anti-wear property, indicating that LS was strongly adhered on the friction surface, and thereby promoted lubrication. Owing to simple preparation, the promising rheological and tribological properties, LS gel hold great potential application in lubricating grease.

scholarly journals Can kaolin function as source of alumina in the synthesis of ZSM-5 without an organic template using a seeding technique?

2016 ◽  
Vol 12 (2) ◽  
Author(s):  
Djoko Hartanto ◽  
Lai Sin Yuan ◽  
Sestriana Mutia Sari ◽  
Djarot Sugiarso ◽  
Irmina Kris Murwani ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Mas Nmr ◽  
Molar Ratio ◽  
Organic Template ◽  
27Al Mas Nmr ◽  
Silica Sols

ZSM-5 has been successfully synthesized by hydrothermal method using Indonesian Bangka kaolin as the aluminium source without an organic template and preactivation by calcination utilizing silicalite and ZSM-5 seedings. There are three parameters that made kaolin a very suitable aluminium source in the synthesis of ZSM-5 by using this method. The first parameter was the presence of types of seeds (silicalite and ZSM-5). Secondly, the molar ratio of Si/Al was in the range of 40–60. Thirdly, the concentrations of NaOH were varied from 6 to 12 mol with 1800 mol water. Interestingly, the use of silicalite seed produced pure ZSM-5 zeolite, whereas analcime and mordenite appeared as side products when ZSM-5 was used as the seed. The above effects can be illustrated by the following mechanism. Kaolin was fully dissolved in the basic mixture solution containing concentrated NaOH and silica sols, and followed by the crystallization in the presence of seeds (silicalite and ZSM-5). The mechanism was postulated on the basis of XRF, XRD, 29Si and 27Al MAS NMR analyses.

Synthesis, characterization and enzymatic degradation of copolymers of ε-caprolactone and hydroxy-fatty acids

2016 ◽  
Vol 88 (12) ◽  
pp. 1191-1201 ◽  
Author(s):  
Diana Aparaschivei ◽  
Anamaria Todea ◽  
Iulia Păuşescu ◽  
Valentin Badea ◽  
Mihai Medeleanu ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Degradation Products ◽  
Hydroxy Fatty Acids ◽  
Molar Ratio ◽  
Molar Ratios ◽  
Chemical Structures ◽  
Buffer Solutions ◽  
Different Temperatures ◽  
Ft Ir ◽  
Candida Antarctica B

AbstractNew copolymers of ε-caprolactone with three hydroxy-fatty acids, 12-hydroxy stearic acid, 16-hydroxyhexadecanoic acid and ricinoleic acid, were synthesized by catalytic polyesterification. The reactions were carried out in solvent-free systems and in organic solvents as well, using tin(II) 2-ethylhexanoate as catalyst, at different temperatures and molar ratios of the comonomers. Cyclic and linear polymeric products with medium molar weight of about 2000 Da have been synthesized and their chemical structures were confirmed by FT-IR, NMR and MALDI-TOF MS analysis. The synthesis parameters were optimized and the ε-caprolactone/hydroxy acid molar ratio was set as 5:1, according to mass spectrometry results. The biodegradability of the newly synthesized polymers was studied in the presence of Candida antarctica B lipase in phosphate buffer solutions (pH=7.4), at 37°C. The weight-loss profile emphasized the degradation of the 16-hydroxyhexadecanoic acid based polymer samples at more than 50% of their initial weight in 18 days of incubation in the presence of the lipase. The composition of the degradation products was assessed using the GC-MS technique and displayed residues of the comonomers moieties.

scholarly journals Removal of Siloxanes from Model Biogas by Means of Deep Eutectic Solvents in Absorption Process

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 241
Author(s):  
Edyta Słupek ◽  
Patrycja Makoś-Chełstowska ◽  
Jacek Gębicki
Keyword(s):  
Experimental Studies ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Tetraethylene Glycol ◽  
Absorption Process ◽  
Molar Ratios ◽  
Screening Model ◽  
Tetrapropylammonium Bromide ◽  
Ft Ir ◽  
Ir Analysis

The paper presents the screening of 20 deep eutectic solvents (DESs) composed of tetrapropylammonium bromide (TPABr) and glycols in various molar ratios, and 6 conventional solvents as absorbents for removal of siloxanes from model biogas stream. The screening was achieved using the conductor-like screening model for real solvents (COSMO-RS) based on the comparison of siloxane solubility in DESs. For the DES which was characterized by the highest solubility of siloxanes, studies of physicochemical properties, i.e., viscosity, density, and melting point, were performed. DES composed of tetrapropylammonium bromide (TPABr) and tetraethylene glycol (TEG) in a 1:3 molar ratio was used as an absorbent in experimental studies in which several parameters were optimized, i.e., the temperature, absorbent volume, and model biogas flow rate. The mechanism of siloxanes removal was evaluated by means of an experimental FT-IR analysis as well as by theoretical studies based on σ-profile and σ-potential. On the basis of the obtained results, it can be concluded that TPABr:TEG (1:3) is a very effective absorption solvent for the removal of siloxanes from model biogas, and the main driving force of the absorption process is the formation of the hydrogen bonds between DES and siloxanes.

scholarly journals Synthesis and spectroscopic characterization of mononuclear/binuclear organotin(IV) complexes with 1H-1,2,4-triazole-3-thiol: Comparative studies of their antibacterial/antifungal potencies

2015 ◽  
Vol 80 (6) ◽  
pp. 755-766 ◽  
Author(s):  
Bushra Parveen ◽  
Iftikhar Bukhari ◽  
Saira Shahzadi ◽  
Saqib Ali ◽  
Shabbir Hussain ◽  
...  
Keyword(s):  
Donor Site ◽  
Free Ligand ◽  
Spectroscopic Characterization ◽  
Molar Ratio ◽  
Ionization Mass ◽  
Spectrometric Data ◽  
Molar Ratios ◽  
Trigonal Bipyramidal ◽  
Ft Ir

A series of di and triorganotin(IV) complexes of the general formula, R2(Cl)SnL (R= Me: 1; Bu: 2) and R3SnL (R = Bu: 3; Ph: 4) have been synthesized by refluxing equivalent molar ratios of orgnotin(IV) chlorides (R2SnCl2/R3SnCl) with the 1H-1,2,4-Triazole-3-thiol (LH) in dry methanol. The synthesized complexes (1-4) were further treated with CS2 and R2SnCl2/R3SnCl in 1:1:1 molar ratio to yield the homobimetallic complexes of the types R2(Cl)SnLCS2Sn(Cl)R2 (R = Me: 5; Bu: 6) and R3SnLCS2SnR3 (R = Bu: 7; Ph: 8). The ligand and the complexes have been characterized by elemental microanalysis (CHNS), FT-IR and multinuclear NMR (1H&13C), and electron ionization mass spectrometry. IR data demonstrates that the dithiocarbamate donor site of the ligand acts in a bidentate manner and there isa trigonal bipyramidal geometry around Sn(IV) in solid state. 1H and 13C NMR data supports the tetrahedralgeometry with thiol donor sites of the ligand while tetra and penta coordinated environments around dithiocarboxylate bound tin(IV) in solution state. Mass spectrometric data supported well the structures of the synthesized complexes. The homobimetallic derivatives were found more active than mononuclear organotin(IV) compounds and free ligand against various strains of bacteria and fungus.

The castor oil based water borne polyurethane dispersion; effect of -NCO/OH content: synthesis, characterization and properties

2017 ◽  
Vol 6 (3) ◽  
Author(s):  
Siva Sankar Panda ◽  
Bishnu Prasad Panda ◽  
Smita Mohanty ◽  
Sanjay K. Nayak
Keyword(s):  
Electron Microscopy ◽  
Castor Oil ◽  
Hard Segment ◽  
Molar Ratio ◽  
Structure Property ◽  
Film Properties ◽  
Molar Ratios ◽  
Structure Property Relationship ◽  
Ft Ir ◽  
Oh Content

AbstractIn this work, a novel bio-renewable castor oil (CO) based aqueous polyurethane (PU) anionic prepolymer dispersion was prepared successfully using isophorone diisocyanate (IPDI) and dimethylol propionic acid (DMPA) as internal emulsifier maintaining NCO/OH molar ratios of 1:3 and 1:5, respectively. The intermolecular H-bonding change, type and intensity of the obtained films with change in molar ratio were investigated by analyzing with Fourier transform-infrared (FT-IR). The morphology of the films was recorded with scanning electron microscopy (SEM) and transmittance electron microscopy (TEM). The coating properties for the film were also studied and discussed. The structure-property relationship with different molar ratios of prepolymer revealed an increasing pattern showing increase in the hard segment content increases the physico-mechanical properties of the CO based PU prepolymer. The FT-IR deconvolution results are in agreement with the film properties. The excellent abrasion resistance properties of CO based films agree well with the surface morphology and FT-IR results. The outcome of the study also suggests use of CO as a better alternative to replace petroleum based polyol for feature perspective.

scholarly journals Synthesis and mechanical and thermal properties of multiblock terpoly(ester-ether-amide) thermoplastic elastomers with variable mole ratio of ether and amide block

2021 ◽  
Vol 23 (4) ◽  
pp. 10-16
Author(s):  
Beata Schmidt ◽  
Joanna Rokicka
Keyword(s):  
Thermal Properties ◽  
Chemical Structure ◽  
Thermoplastic Elastomers ◽  
Molar Ratio ◽  
Mechanical And Thermal Properties ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Ft Ir ◽  
Trimethylene Terephthalate ◽  
Nmr Methods

Abstract A series of the terpolymers of poly[(trimethylene terephthalate)-block-(oxytetramethylene)-block-laurolactam] with a variable molar ratio of ether and amide block and constant molecular weights of PA12 = 2000 g/mole and PTMO = 1000 g/mole have been obtained. The influence of changes of these molar ratios on the functional properties and the values of phase change temperatures of the products have been determined. The thermal properties and the phase separation of obtained systems were defined by DSC, DMTA and WAXS methods. The chemical structure of obtained materials was studied by FT-IR and 13C NMR methods. The mechanical and elastic properties of these polymers were evaluated.

Sign in / Sign up

Export Citation Format

Share Document