Recent Advances in the Development and Application of Clay-Based Hybrid and Composite Materials

Dear Colleagues,

This Special Issue, "Recent Advances in the Development and Application of Clay-Based Hybrid and Composite Materials", has been launched with the aim of collecting and disseminating the results of original scientific research, both theoretical and applied, concerning the diverse fields of use for these newly obtained materials.

In recent years, the exploration of clay-based hybrid and composite materials has gained momentum due to their remarkable ability to combine structural robustness, tailored physicochemical properties, and multifunctionality. These systems leverage the intrinsic structure of clay minerals, facilitating precise intercalation processes, surface modification, and interface engineering, which are essential elements for achieving materials with optimized performance.

Clay minerals, predominantly phyllosilicates and other layered or fibrous silicates (including classic examples such as montmorillonite, kaolinite, and halloysite, as well as attapulgite and mica mineral forms), possess a distinctive architecture. This architecture, whether it is a lamellar structure characteristic of the majority of phyllosilicates (like montmorillonite and mica) or a fibrous structure (as seen in attapulgite), facilitates key modification processes.

The laminar crystalline structure specifically facilitates intercalation—the insertion of organic or inorganic species between clay layers—leading to expanded interlayer spacing and enhanced composite interactions. Intercalation mechanisms typically involve ion exchange, electrostatic attraction, or covalent bonding, depending on the nature of the guest molecules and the clay surface. Modifying the surfaces of clays is performed in order to alter their hydrophilicity/hydrophobicity balance and improve compatibility with various matrices. Organic modification, often achieved through surfactant or silane treatments, involves the substitution of native cations with organic moieties, leading to the formation of organoclays with tunable surface chemistries. Such modifications directly influence key physicochemical properties—such as surface charge, wettability, and thermal stability—and thereby dictate the interfacial interactions within the hybrid system. The development of clay-derived hybrid systems is contingent upon a profound understanding of their structural and physicochemical aspects, particularly their mechanisms of intercalation, surface modification, and interface engineering. These strategies enable precise control over structure–property relationships, facilitating the design of multifunctional materials that are tailored for specific applications, such as high-performance materials in packaging, regenerative medicine, heritage conservation, automotive, and aerospace industries, or for environmental remediation. In electronics and energy storage, the crystalline order and nanostructure allow for the development of conductive or semi-conductive clay-based composites, enabling applications for sensors, supercapacitors, and batteries.

Coupled with sustainable synthesis approaches, researchers in this area seek to develop environmentally friendly, high-performance composites that address the challenges imposed by modern technology and environmental stewardship.

The original research and review papers published in this Special Issue will cover various topics, including, but not limited to, the following:

• Clay functionalization and intercalation chemistry;
• Structural and morphological characterization;
• Organo-clay nanocomposites;
• Controlled-release systems for drugs/fertilizers/pesticides;
• Dermatocosmetic products;
• Chemical sensors and BioSensors;
• Building materials;
• Pollutant adsorbers;
• Materials for 3D printing.

Dr. Florentina Monica Raduly
Prof. Dr. Pier Carlo Ricci
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 250 words) can be sent to the Editorial Office for assessment.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Crystals is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2100 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.