scholarly journals Titania-Clay Mineral Composites for Environmental Catalysis and Photocatalysis

Catalysts ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1087
Author(s):  
Ewa M. Serwicka
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Photocatalytic Performance ◽  
Functional Materials ◽  
Building Blocks ◽  
Titania Nanoparticles ◽  
Environmental Catalysis ◽  
Physical And Chemical ◽  
Rich History

The use of titania-based composite materials in the field of heterogeneous catalysis and photocatalysis has a long and rich history. Hybrid structures combining titania nanoparticles with clay minerals have been extensively investigated for nearly four decades. The attractiveness of clay minerals as components of functional materials stems primarily from their compositional versatility and the possibility of using silicate lamellae as prefabricated building blocks ready to be fitted into the desired nanoconstruction. This review focuses on the evolution over the years of synthetic strategies employed for the manufacturing of titania–clay mineral composites with particular attention to the role of the adopted preparative approach in shaping the physical and chemical characteristics of the materials and enabling, ultimately, tuning of their catalytic and/or photocatalytic performance.

Clay minerals for nanocomposites and biotechnology: surface modification, dynamics and responses to stimuli

Clay Minerals ◽  
2012 ◽  
Vol 47 (2) ◽  
pp. 205-230 ◽  
Author(s):  
H. Heinz
Keyword(s):  
Surface Modification ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Self Assembly ◽  
Functional Materials ◽  
Surface Characteristics ◽  
Mineral Surface ◽  
Thermal Transitions ◽  
Wide Range ◽  
Potential Applications

AbstractClay minerals find a wide range of application in composites, paints, drilling liquids, cosmetics, and medicine. This article reviews chemical and physical properties of natural and organically modified clay minerals to understand the nanometre-scale structure, surface characteristics, and application in functional materials. The relation between fundamental properties and materials design is emphasized and illustrated by examples. The discussion comprises the following: an overview; surface structure and cation density; solubility and solubility reversal by surface modification; the degree of covalent and ionic bonding represented by atomic charges; the distribution of metal substitution sites; measurements and simulations of interfacial properties at the nanometre scale; self-assembly, packing density, and orientation of alkylammonium surfactants on the clay mineral surface; the density and chain conformation of surfactants in organic interlayer spaces; the free energy of exfoliation in polymer matrices and modifications by tuning the cleavage energy; thermal transitions, diffusion, and optical responses of surfactants on the mineral surface; elastic moduli and bending stability of clay layers; and the adsorption mechanism of peptides onto clay mineral surfaces in aqueous solution. Potential applications in biotechnology and other future uses are described.

Microstructure of Unburned Clay and its Shrinkage during Drying

2016 ◽  
Vol 837 ◽  
pp. 109-112 ◽  
Author(s):  
Tereza Otcovska ◽  
Pavel Padevět
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Building Material ◽  
Basic Problem ◽  
Volume Changes ◽  
Material Characteristics ◽  
Increasing Demand ◽  
Building Practice ◽  
Civil Engineers

Unburned clay was used for the traditional engineering works for thousands years. Its qualities have not been too appreciated in the last few decades. Because of that, its material characteristics were never researched very rigorously. In last years, we could see increasing demand for use of this building material in building practice and research. The basic problem that should be mitigated by civil engineers handling unburned clay is its considerable shrinkage during drying. The degree of shrinkage depends on the amount of mixture water and on the amount and type of clay minerals. In the unburned clay, like in the cement, clay minerals play role of the binder. The problem is that clay minerals are causing volume changes. This paper is focused on the degree of shrinkage and its dependence on the species and quantity of clay mineral.

Non-Crystallographic Nanopores in Single Crystals: A New Approach in Nanomaterials Chemistry

2004 ◽  
Vol 443-444 ◽  
pp. 217-222
Author(s):  
Claus J.H. Jacobsen ◽  
Iver Schmidt ◽  
Michael Brorson ◽  
Astrid Boisen ◽  
Thomas W. Hansen ◽  
...  
Keyword(s):  
Single Crystals ◽  
Chemical Properties ◽  
Metal Sulfide ◽  
Building Blocks ◽  
New Approach ◽  
New Family ◽  
Physical And Chemical ◽  
And Chemical Properties

Nanomaterials are the building blocks of nanotechnology. Recently, nanotube materials have attracted considerable attention due to their unique physical and chemical properties. Here we discuss how nanotubes can be used as templates for preparation of a new family of materials, the nanoporous single crystals, and for the preparation of metal sulfide nanotube materials. Today, the characterization of these materials depends heavily on electron microscopy. However, as rational synthesis schemes are becoming available, more well-defined, homogeneous nanotube samples will be produced and the role of diffraction techniques may increase.

The Role of the City in Merovingian Francia

2020 ◽  
pp. 581-610
Author(s):  
S. T. Loseby
Keyword(s):  
Roman Empire ◽  
Urban Communities ◽  
Late Antiquity ◽  
Building Blocks ◽  
Urban Network ◽  
City Councils ◽  
Royal Courts ◽  
Range Of Functions ◽  
Fierce Competition

The Merovingians inherited an urban network from the Roman Empire that remained substantially intact. Although Gallic cities had long been declining in extent and sophistication, during late antiquity their landscapes were adapted to contemporary priorities through the provision of walls and churches, and their politics was transformed by the emergence of bishops as leaders of urban communities. When the upper tiers of imperial administration disappeared, this equipped the vast majority of cities to survive as the basic building blocks of Merovingian kingdoms that were initially conceived as aggregations of city–territories. In ruling through their cities, the Merovingians expanded upon existing mechanisms for the extraction of taxes and services, while relying on centrally appointed bishops and counts rather than city councils for the projection of their authority. This generated fierce competition between kings for control of cities and among local elites for positions of power within them. In the later Merovingian period, however, the significance of cities diminished as stable territorial kingdoms emerged, political practice was centralized around the royal courts, and the Roman administrative legacy finally disintegrated. But the cities remained preeminent religious centers, and, with the beginnings of economic revival, continued to perform a range of functions unmatched by other categories of settlement.

scholarly journals Characterizing the building blocks of Problematic Use of the Internet (PUI): The role of obsessional impulses and impulsivity traits among Italian young adults

2021 ◽  
Vol 106 ◽  
pp. 152225
Author(s):  
Francesco Di Carlo ◽  
Mauro Pettorruso ◽  
Maria Chiara Alessi ◽  
Elena Picutti ◽  
Rebecca Collevecchio ◽  
...  
Keyword(s):  
Young Adults ◽  
Building Blocks ◽  
The Internet ◽  
Problematic Use ◽  
Use Of The Internet

scholarly journals DFT Study of Electronic Structure and Optical Properties of Kaolinite, Muscovite, and Montmorillonite

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 618
Author(s):  
Layla Shafei ◽  
Puja Adhikari ◽  
Wai-Yim Ching
Keyword(s):  
Mechanical Properties ◽  
Optical Properties ◽  
Electronic Structure ◽  
Hydrogen Bonds ◽  
Clay Minerals ◽  
Clay Mineral ◽  
Bond Order ◽  
Deep Understanding ◽  
Pharmaceutical Applications ◽  
Structure Properties

Clay mineral materials have attracted attention due to their many properties and applications. The applications of clay minerals are closely linked to their structure and composition. In this paper, we studied the electronic structure properties of kaolinite, muscovite, and montmorillonite crystals, which are classified as clay minerals, by using DFT-based ab initio packages VASP and the OLCAO. The aim of this work is to have a deep understanding of clay mineral materials, including electronic structure, bond strength, mechanical properties, and optical properties. It is worth mentioning that understanding these properties may help continually result in new and innovative clay products in several applications, such as in pharmaceutical applications using kaolinite for their potential in cancer treatment, muscovite used as insulators in electrical appliances, and engineering applications that use montmorillonite as a sealant. In addition, our results show that the role played by hydrogen bonds in O-H bonds has an impact on the hydration in these crystals. Based on calculated total bond order density, it is concluded that kaolinite is slightly more cohesive than montmorillonite, which is consistent with the calculated mechanical properties.

Critical role of nanocomposites at air–water interface: From aqueous foams to foam-based lightweight functional materials

2021 ◽  
Vol 416 ◽  
pp. 129121
Author(s):  
Kai Yu ◽  
Bin Li ◽  
Huagui Zhang ◽  
Zhentao Wang ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Critical Role ◽  
Functional Materials ◽  
Water Interface ◽  
Aqueous Foams ◽  
Air Water Interface

scholarly journals A Global Review on Short Peptides: Frontiers and Perspectives

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 430
Author(s):  
Vasso Apostolopoulos ◽  
Joanna Bojarska ◽  
Tsun-Thai Chai ◽  
Sherif Elnagdy ◽  
Krzysztof Kaczmarek ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Targeted Delivery ◽  
Swot Analysis ◽  
Functional Materials ◽  
Great Promise ◽  
Short Peptides ◽  
Altered Peptide Ligands ◽  
Short Peptide ◽  
Domains Of Life

Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide “drugs” initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed.

scholarly journals Remediation of mercury-contaminated soils and sediments using biochar: a critical review

Biochar ◽  
2021 ◽  
Author(s):  
Qian Yang ◽  
Yongjie Wang ◽  
Huan Zhong
Keyword(s):  
Health Risks ◽  
Contaminated Soils ◽  
Functional Materials ◽  
Redox Conditions ◽  
Existing Problems ◽  
Soils And Sediments ◽  
Underlying Mechanisms ◽  
Biochar Amendment

AbstractThe transformation of mercury (Hg) into the more toxic and bioaccumulative form methylmercury (MeHg) in soils and sediments can lead to the biomagnification of MeHg through the food chain, which poses ecological and health risks. In the last decade, biochar application, an in situ remediation technique, has been shown to be effective in mitigating the risks from Hg in soils and sediments. However, uncertainties associated with biochar use and its underlying mechanisms remain. Here, we summarize recent studies on the effects and advantages of biochar amendment related to Hg biogeochemistry and its bioavailability in soils and sediments and systematically analyze the progress made in understanding the underlying mechanisms responsible for reductions in Hg bioaccumulation. The existing literature indicates (1) that biochar application decreases the mobility of inorganic Hg in soils and sediments and (2) that biochar can reduce the bioavailability of MeHg and its accumulation in crops but has a complex effect on net MeHg production. In this review, two main mechanisms, a direct mechanism (e.g., Hg-biochar binding) and an indirect mechanism (e.g., biochar-impacted sulfur cycling and thus Hg-soil binding), that explain the reduction in Hg bioavailability by biochar amendment based on the interactions among biochar, soil and Hg under redox conditions are highlighted. Furthermore, the existing problems with the use of biochar to treat Hg-contaminated soils and sediments, such as the appropriate dose and the long-term effectiveness of biochar, are discussed. Further research involving laboratory tests and field applications is necessary to obtain a mechanistic understanding of the role of biochar in reducing Hg bioavailability in diverse soil types under varying redox conditions and to develop completely green and sustainable biochar-based functional materials for mitigating Hg-related health risks.

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