Synthesis of hybrid zeolites using a solvent-free method in the presence of different organosilanes

Petkowicz, Diego Ivan; Canal, Sabrine; Finger, Pedro H.; Mignoni, Marcelo Luís; Santos, João Henrique Zimnoch dos

doi:10.1016/j.micromeso.2016.11.030

Cited by 25 publications

(10 citation statements)

References 35 publications

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“…The third weight loss in the range of 480–550 °C might be due to the degradation of the rest of the organic phase 32 . In this step, the weight loss in the temperature range of 490 °C-506 °C seems to be ascribed to the decomposition of the CTS 33 . Moreover, the decomposition temperature is notably higher than the boiling point (195 °C) of the CTS because the CTS forms strong chemical bonds with the organic phase.…”

Section: Resultsmentioning

confidence: 92%

Mechanism confirmation of organofunctional silanes modified sodium silicate/polyurethane composites for remarkably enhanced mechanical properties

Liang

Gao

Sun

et al. 2021

Sci Rep

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Hybrid reinforced sodium silicate/polyurethane (SS/PU) composites mainly derived from low-cost SS and polyisocyanate are produced by a one-step method based on the addition of 3-chloropropyltrimethoxysilane (CTS). The wettability of SS on PU substrate surface is much improved as CTS content increases from 0.0 to 3.5 wt%. Furthermore, with 2.5 wt% of CTS optimal addition, the fracture surface morphology and elemental composition of the resulting SS/PU composites are characterized, as well as mechanical properties, chemical structure and thermal properties. The results indicate that the CTS forms multiple physical and chemical interactions with the SS/PU composites to induce an optimized organic–inorganic hybrid network structure thus achieving simultaneous improvement of compressive strength, flexural strength, flexural modulus and fracture toughness of the SS/PU composites, with the improvement of 12.9%, 6.6%, 17.5% and 9.7%, respectively. Moreover, a reasonable mechanism explanation for CTS modified SS/PU composites is confirmed. Additionally, the high interface areas of the organic–inorganic phase and the active crosslinking effect of the CTS are the main factors to determine the curing process of the SS/PU composites.

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Section: Resultsmentioning

confidence: 92%

Mechanism confirmation of organofunctional silanes modified sodium silicate/polyurethane composites for remarkably enhanced mechanical properties

Liang

Gao

Sun

et al. 2021

Sci Rep

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“…Laboratory works show that the solvent‐free synthesis of zeolites is feasible by milling [14–26] . This method is commonly called mechanochemical.…”

Section: Introductionmentioning

confidence: 99%

Key Factors During the Milling Stage of the Seed‐assisted and Solvent‐free Synthesis of MFI and Catalytic Behavior in the Alkylation of Phenol with Tert‐butyl Alcohol

et al. 2021

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The so-called mechanochemical method for the synthesis of zeolites reduces the generation of liquid residues and gaseous pollutants as compared to the conventional solvothermal method. Different types of zeolites have been synthesized at the laboratory scale with this method using mostly pestle and mortar. However, such an approach hinders both the systematic comprehension of the effects of the input variables of the milling process and its further scale-up towards the synthesis of the zeolites and their catalytic application. This work investigates the influence of key factors involved in the ball milling stage of the mechanochemical route for the synthesis of MFI done with the assistance of a commercial MFI seed and in the absence of solvents over the most salient physicochemical properties of this type of materials, i.e. the recovery percentage, production cost, morphology, surface area and porosity, crystallinity, acidity of the protonated MFI and catalytic performance. The synthesis of the materials was planned and executed following a full 2 4 factorial experiment whose input variables were the Na2O/SiO2 and H2O/SiO2 molar ratios and the milling time and speed. The effects of both main and interaction factors over key physicochemical properties, and catalytic behavior of the synthesized materials on the alkylation of phenol with tert-butyl alcohol were established within the explored sampling space. Results showed that the Na2O/SiO2 molar ratio plays a key role for the mechanochemical synthesis of MFI, since this variable may direct the synthesis to the preferential production of MOR instead of MFI. On the other hand, it was found that the milling time and speed and their interactions markedly impact the textural properties of MFI. Furthermore, the triple interaction between the input variables affected the concentration of Lewis acid sites of the produced materials. These effects were rationalized by considering that sodium can act as a structure directing agent during the mechanochemical synthesis of MFI and also can promote the incorporation of aluminum to its structure. On the other hand, the milling time and speed are non-linearly correlated to the milling energy required for forming the aluminosilicate precursor that crystallizes during the hydrothermal stage of the process. Overall, all the zeolites synthesized by the mechanochemical route were less crystalline than both the MFI used as seed and an MFI synthesized by solgel. This was associated to the formation of amorphous agglomerates around the zeolitic crystals. Finally, the catalytic behavior of the mechanochemical MFI zeolites in the studied reaction was found to be linearly and positively correlated with both the concentration of BrØnsted of sites and with the density of acid sites. The catalytic tendencies were consistent with the proposal of a stepwise Langmuir-Hinshelwood mechanism for the alkylation of phenol with tert-butyl alcohol.

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“…The third weight loss in the range of 480 °C-550 °C might be due to the degradation of the rest of the organic phase 22 . In this step, the weight loss in the temperature range of 490 °C-506 °C seems to be ascribed to the decomposition of the CTS 23 . Moreover, the decomposition temperature is notably higher than the boiling point (195 °C) of the CTS becasue the CTS forms strong chemical bonds with the organic phase.…”

Section: Thermo Gravimetric Analysis Of Wg/pu Compositesmentioning

confidence: 92%

Mechanism Confirmation of Organofunctional Silanes Modified Water Glass/Polyurethane-Urea Composites for Remarkably Enhanced Mechanical Properties

Liang

Gao

Sun

et al. 2021

Preprint

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Hybrid reinforced water glass/polyurethane-urea (WG/PU) composites mainly derived from low-cost WG and polyisocyanate are produced in the presence of 3-chloropropyltrimethoxysilane (CTS). The wettability of WG on PU substrate surface is significantly improved as CTS content increases from 0.0 wt% to 3.5 wt%. Furthermore, with 2.5 wt% of CTS optimal addition, the fracture surface morphology and elemental composition of the resulting WG/PU composites are characterized, as well as mechanical properties, chemical structure and thermal properties. The results indicate that the CTS forms multiple physical and chemical interactions with the WG/PU composites to induce an optimized organic-inorganic hybrid network structure thus achieving simultaneous improvement of compressive strength, flexural strength, flexural modulus and fracture toughness of the WG/PU composites, with the improvement of 12.9%, 6.6%, 17.5% and 9.7%, respectively. Moreover, the CTS in the WG/PU composites has a significant influence on the curing process of the WG/PU composites by accelerating the rate of mass and heat transfer. Additionally, a reasonable mechanism explanation for CTS modified WG/PU composites is confirmed.

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Synthesis of hybrid zeolites using a solvent-free method in the presence of different organosilanes

Cited by 25 publications

References 35 publications

Mechanism confirmation of organofunctional silanes modified sodium silicate/polyurethane composites for remarkably enhanced mechanical properties

Mechanism confirmation of organofunctional silanes modified sodium silicate/polyurethane composites for remarkably enhanced mechanical properties

Key Factors During the Milling Stage of the Seed‐assisted and Solvent‐free Synthesis of MFI and Catalytic Behavior in the Alkylation of Phenol with Tert‐butyl Alcohol

Mechanism Confirmation of Organofunctional Silanes Modified Water Glass/Polyurethane-Urea Composites for Remarkably Enhanced Mechanical Properties

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