Sign in to use this feature.

Years

Between: -

Subjects

remove_circle_outline
remove_circle_outline
remove_circle_outline
remove_circle_outline

Journals

Article Types

Countries / Regions

Search Results (4)

Search Parameters:
Keywords = offretite

Order results
Result details
Results per page
Select all
Export citation of selected articles as:
13 pages, 4680 KB  
Review
Important Synthesis Parameters Affecting Crystallization of Zeolite T: A Review
by Siti Z. Patuwan and Sazmal E. Arshad
Materials 2021, 14(11), 2890; https://doi.org/10.3390/ma14112890 - 28 May 2021
Cited by 16 | Viewed by 5123
Abstract
Synthesis of zeolite T with a variety of desired characteristics necessitates extensive work in formulation and practical experiments, either by conventional hydrothermal methods or aided with different approaches and synthesis techniques, such as secondary growth or microwave irradiation. The objectives of this review [...] Read more.
Synthesis of zeolite T with a variety of desired characteristics necessitates extensive work in formulation and practical experiments, either by conventional hydrothermal methods or aided with different approaches and synthesis techniques, such as secondary growth or microwave irradiation. The objectives of this review are to adduce the potential work in zeolite T (Offretite-Erionite) synthesis, evaluating determining factors affecting the synthesis and quality of zeolite T crystals. Attention is given to extensive studies that interconnect with other significant findings. Full article
Show Figures

Graphical abstract

9 pages, 2403 KB  
Article
Offretite Zeolite Single Crystals Synthesized by Amphiphile-Templating Approach
by Eng-Poh Ng, Nur Hidayahni Ahmad, Fitri Khoerunnisa, Svetlana Mintova, Tau Chuan Ling and T. Jean Daou
Molecules 2021, 26(8), 2238; https://doi.org/10.3390/molecules26082238 - 13 Apr 2021
Cited by 1 | Viewed by 3284
Abstract
Offretite zeolite synthesis in the presence of cetyltrimethylammonium bromide (CTABr) is reported. The offretite crystals were synthesized with a high crystallinity and hexagonal prismatic shape after only 72 h of hydrothermal treatment at 180 °C. The CTABr has dual-functions during the crystallization of [...] Read more.
Offretite zeolite synthesis in the presence of cetyltrimethylammonium bromide (CTABr) is reported. The offretite crystals were synthesized with a high crystallinity and hexagonal prismatic shape after only 72 h of hydrothermal treatment at 180 °C. The CTABr has dual-functions during the crystallization of offretite, viz. as structure-directing agent and as mesoporogen. The resulting offretite crystals, with a Si/Al ratio of 4.1, possess more acid sites than the conventional offretite due to their high crystallinity and hierarchical structure. The synthesized offretite is also more reactive than its conventional counterpart in the acylation of 2-methylfuran for biofuel production under non-microwave instant heating condition, giving 83.5% conversion with 100% selectivity to the desired product 2-acetyl-5-methylfuran. Hence, this amphiphile synthesis approach offers another cost-effective and alternative route for crystallizing zeolite materials that require expensive organic templates. Full article
(This article belongs to the Collection Porous Materials)
Show Figures

Graphical abstract

23 pages, 9443 KB  
Article
Real-Time Observation of Fibrous Zeolites Reactivity in Contact with Simulated Lung Fluids (SLFs) Obtained by Atomic Force Microscope (AFM)
by Matteo Giordani, Georgia Cametti, Fulvio Di Lorenzo and Sergey V. Churakov
Minerals 2019, 9(2), 83; https://doi.org/10.3390/min9020083 - 29 Jan 2019
Cited by 20 | Viewed by 5968
Abstract
Inhalation of fibrous erionite particles has been linked to malignant mesothelioma. Accordingly, erionite is considered the most carcinogenic mineral. The reactivity and the nature of erionite biotoxicity has been the subject of intensive research. Despite very close chemical and structural relationships between erionite [...] Read more.
Inhalation of fibrous erionite particles has been linked to malignant mesothelioma. Accordingly, erionite is considered the most carcinogenic mineral. The reactivity and the nature of erionite biotoxicity has been the subject of intensive research. Despite very close chemical and structural relationships between erionite and offretite, the reactivity of offretite in lung fluids remains unknown. In this paper, the interaction of erionite and offretite surfaces with simulated lung fluids was investigated by means of in situ atomic force microscope (AFM). To simulate different environments in the lungs, artificial lysosomal fluid (ALF) and Gamble’s solution were used. In ALF (4.15 < pH < 4.31) the dissolution of erionite and offretite surfaces was detected, as well as an evident removal of particles (mainly attributed to impurities) from the crystal faces. Instead, the growth of a layer of a yet unknown phase on the surface of both zeolites was observed during the interaction with Gamble’s solution (7.4 < pH < 8.48). The thickness of this layer reached a few tens of nanometers and covered all the observed areas. The understanding of the observed processes is of paramount importance, since they could be potentially involved in the mechanisms triggering the toxicological effects of erionite fibres. Full article
(This article belongs to the Special Issue Natural Zeolites)
Show Figures

Figure 1

16 pages, 1746 KB  
Article
Prismatic to Asbestiform Offretite from Northern Italy: Occurrence, Morphology and Crystal-Chemistry of a New Potentially Hazardous Zeolite
by Michele Mattioli, Matteo Giordani, Pierluca Arcangeli, Laura Valentini, Matteo Boscardin, Alessandro Pacella and Paolo Ballirano
Minerals 2018, 8(2), 69; https://doi.org/10.3390/min8020069 - 14 Feb 2018
Cited by 24 | Viewed by 5958
Abstract
A multi-methodological approach, based upon field investigation, morphological characterization, chemical analysis and structure refinement was applied to different samples of fibrous offretite, a new potentially hazardous zeolite recently discovered in northern Italy. Their morphology ranges from stocky-prismatic to asbestiform. All the investigated fibers [...] Read more.
A multi-methodological approach, based upon field investigation, morphological characterization, chemical analysis and structure refinement was applied to different samples of fibrous offretite, a new potentially hazardous zeolite recently discovered in northern Italy. Their morphology ranges from stocky-prismatic to asbestiform. All the investigated fibers may be considered as “inhalable”, and they are well within the range of the “more carcinogenic fibers” regarding diameter. As regards the length, the main mode observed in the asbestiform samples is 20–25 μm, and ~93% of the measured fibers are >5 μm and may be significantly associated with carcinogenesis also in terms of lengths. The chemical-structural features of the investigated fibers are comparable: the extra-framework cations K+, Mg2+ and Ca2+ are present in all samples in similar proportions, and refined cell parameters are similar among the samples. Offretite occurs in 60% of the investigated sites, with an estimated amount up to 75 vol % of the associated minerals. The presence of this mineral could be of concern for risk to human health, especially if one considers the vast number of quarries and mining-related activities that are operating in the zeolite host rocks. Full article
(This article belongs to the Special Issue Occurrence, Crystal-Chemistry and Properties of Fibrous Minerals)
Show Figures

Figure 1

Back to TopTop