Submit to Special Issue Submit Abstract to Special Issue Review for Gels Propose a Special Issue

Journal Menu

Journal Browser

Innovative Gels: Structure, Properties, and Emerging Applications

Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Related Special Issue
Published Papers

A special issue of Gels (ISSN 2310-2861). This special issue belongs to the section "Gel Analysis and Characterization".

Deadline for manuscript submissions: 20 September 2026 | Viewed by 11453

Share This Special Issue

Special Issue Editors

Dr. Teodora Staicu

E-Mail Website
Guest Editor

Department of Physical Chemistry, University of Bucharest, 4-12 Regina Elisabeta Blvd., 030018 Bucharest, Romania
Interests: polymers; surfactants; polymer rheology; biopolymers; hydrogels; pressure-sensitive adhesives
Special Issues, Collections and Topics in MDPI journals

Dr. Marin Micutz

E-Mail Website
Guest Editor

Department of Physical Chemistry, University of Bucharest, 4-12 Regina Elisabeta Blvd., 030018 Bucharest, Romania
Interests: pressure-sensitive adhesives; polymer synthesis; collagen extraction and processing; collagen-based materials; polymer/biopolymer gels; polymer-surfactant interactions; rheology
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

As physically and/or chemically crosslinked 3D systems, gels have received much attention in recent decades, to such an extent that most fundamental and applied research in the field of materials refers, more or less, to the gel state of matter.

Depending on the nature of the immobilized liquid phase, there are two general kinds of gels: hydrogels—in which the majority of the liquid phase is aqueous—and organogels—in which the immobilized liquid consists of an organic solvent or a homogenous mixture of organic solvents, irrespective of the characteristics of the gelator(s) (natural, synthetic, or with low or high molecular mass) and the attractive interactions (physical or chemical between gelator molecules) through which the entire gel-like system is crosslinked.

Beyond the countless applications of hydrogels and organogels in chemistry, radiochemistry, biochemistry, pharmacology, reconstruction and regenerative medicine, cosmetics, the food industry, biotechnology, and environmental protection, it is important and necessary to strive for the continuous adjustment and development of methods for the investigation and characterization of such complex systems.

Considering that gels can generally be studied and characterized in their swollen (as-prepared) and/or dry state (via air-drying or freeze-drying), this Special Issue focuses on the latest results, obtained using appropriate methods of investigation, characterization, and analyses, regarding the relationships between the structural peculiarities of such 3D networks, as well as their properties and potential applications.

Dr. Teodora Staicu
Dr. Marin Micutz
Guest Editors

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. Gels 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.

Keywords

hydrogels
organogels
gel characterization
gel properties
gel applications

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
Reprint: MDPI Books provides the opportunity to republish successful Special Issues in book format, both online and in print.

Further information on MDPI's Special Issue policies can be found here.

Related Special Issue

Synthetic, Natural and Hybrid Gels Intended for Various Applications in Gels (12 articles)

Published Papers (8 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

Jump to: Review

18 pages, 3440 KB

Open AccessArticle

Influence of Vanadium-Titanium Slag Substitution on Properties and Microstructure of Blast Furnace Slag-Steel Slag-Desulfurization Gypsum Gel System

by Junyao Liu, Siqi Zhang, Huifen Yang, Wen Ni, Dongshang Guan, Xingyang Xu and Yu Zhan

Gels 2026, 12(1), 3; https://doi.org/10.3390/gels12010003 - 19 Dec 2025

Viewed by 437

Abstract

The comprehensive utilisation of solid waste is a primary approach to enhancing the utilisation efficiency of mineral resources. However, vanadium-titanium slag has long faced insufficient resource utilisation due to its low activity. To address this issue, this study integrated macro and micro analytical methods to systematically investigate the effect of mechanical grinding on the activity of vanadium-titanium slag, as well as its performance when partially replacing blast furnace slag in the system of slag—converter steel slag-desulfurization gypsum ternary gel system. Additionally, the hydration mechanism of this cementitious system was analysed. The research results indicate that mechanical grinding can significantly improve the activity index of vanadium-titanium slag and increase its specific surface area. Replacing an appropriate amount of slag with vanadium-titanium slag in the slag-steel slag-desulfurization gypsum ternary gel system can effectively enhance the mechanical properties of the cementitious system. The optimal mix proportion of vanadium-titanium slag:slag:steel slag:desulfurization gypsum as 10.5:31.5:42:16 with a water-to-binder ratio of 0.32, under which the 28-day compressive strength of the specimen reached 33.50 MPa. Through multiple microscopic analysis techniques, it was found that in the alkaline environment and sulfate excitation (provided by steel slag hydration and desulfurization gypsum), the cementitious system generates hydration products such as ettringite (AFt), C–S–H, and C–A–S–H gels. Some unreacted vanadium-titanium slag particles are wrapped and intertwined by hydrated calcium silicate (aluminium) gels, forming a stable dendritic structure that provides support for the system’s strength development. Full article

(This article belongs to the Special Issue Innovative Gels: Structure, Properties, and Emerging Applications)

► Show Figures

Figure 1

21 pages, 6002 KB

Open AccessArticle

Effect of Ultrasonic Treatment of Dispersed Carbon Nanocomposite Media on the Formation, Electrical Conductivity, and Degradation of a Hydrogel for Metallic Stimulation Electrodes

by Mikhail Savelyev, Artem Kuksin, Denis Murashko, Ekaterina Otsupko, Victoria Suchkova, Kristina Efremova, Pavel Vasilevsky, Ulyana Kurilova, Sergey Selishchev and Alexander Gerasimenko

Gels 2025, 11(12), 1004; https://doi.org/10.3390/gels11121004 - 12 Dec 2025

Viewed by 503

Abstract

This study investigates the impact of ultrasonic treatment on the deagglomeration of aggregates of single-walled carbon nanotubes (SWCNTs) and reduced graphene oxide (rGO). The aim of the research is to enhance the electrical conductivity of a biopolymer hydrogel designed for coating metallic neurostimulation electrodes. Biocompatible coating materials are essential for the safe long-term function of implants within the body, enabling the transmission of nerve impulses to external devices for signal conversion and neurostimulation. Dynamic light scattering (DLS) was employed to monitor the dispersion state, in conjunction with measurements of specific electrical conductivity. The mass loss and swelling capacity were evaluated over an 80-day period to account for the effects of degradation during in vitro studies. Samples of flexible–elastic hydrogels for electrodes with complex geometry were formed by the photopolymerization of a photopolymerizable medium, similar to a photoresist. Analysis of the dependence of temperature and normalized optical transmittance on the duration of laser photopolymerization made it possible to determine the optimal polymerization temperature for the photopolymerizable medium as −28 °C. This temperature regime ensures maximum reproducibility of hydrogel formation and eliminates the presence of unpolymerized areas. The article presents a biopolymer hydrogel with SWCNTs and rGO nanoparticles in a 1:1 ratio. It was found that sufficient specific electrical conductivity is achieved using SWCNTs with a characteristic hydrodynamic radius of R = 490 nm and rGO with R = 210 nm (sample Col/BSA/CS/Eosin Y/SWCNTs (490 nm)/rGO 4). The photopolymerized hydrogel 4 demonstrated sufficient biocompatibility, exceeding the control sample by 16%. According to the results of in vitro studies over 80 days, this sample exhibited moderate degradation of 45% while retaining its swelling ability. The swelling degree decreased by 50% compared to the initial value of 170%. The presented hydrogel 4 is a promising coating material for implantable metallic neurostimulation electrodes, enhancing their stability in the physiological environment. Full article

(This article belongs to the Special Issue Innovative Gels: Structure, Properties, and Emerging Applications)

► Show Figures

Figure 1

13 pages, 2867 KB

Open AccessArticle

Microstructure and Photocatalytic Performance of BaTi₅O₁₁ Nanocrystals Synthesized via Sol-Gel Method Mediated by Organic Solvents

by Honghua Wang, Tianchen Gao, Xinyi Li, Yuci Huang, Junjie Wang, Zhixiong Huang and Dongyun Guo

Gels 2025, 11(9), 706; https://doi.org/10.3390/gels11090706 - 3 Sep 2025

Viewed by 756

Abstract

BaTi₅O₁₁ nanocrystals were synthesized via a sol–gel method employing different organic solvents. The influence of solvent choice on microstructure and photocatalytic performance was investigated through methylene blue (MB) degradation under UV light irradiation. The monoclinic BaTi₅O₁₁ nanocrystals were successfully synthesized, where solvent selection significantly affected their grain size and Brunauer–Emmett–Teller (BET) surface area. The BaTi₅O₁₁ nanocrystals synthesized using polyethylene glycol-200 (PEG-200) exhibited the highest BET surface area (9.78 m²/g) and smallest average pore size (17.8 nm). The BaTi₅O₁₁ nanocrystals also displayed a larger optical bandgap (3.61 eV), attributed to pronounced quantum confinement and surface effects. Consequently, the PEG-200-derived BaTi₅O₁₁ photocatalyst achieved complete MB degradation within 30 min under UV light irradiation. This enhanced performance was attributed to the high BET surface area providing abundant active sites. Furthermore, the BaTi₅O₁₁ nanocrystal photocatalyst maintained excellent reusability and stability over four consecutive cycles. Full article

(This article belongs to the Special Issue Innovative Gels: Structure, Properties, and Emerging Applications)

► Show Figures

Figure 1

24 pages, 4277 KB

Open AccessArticle

The Behaviour of Contaflex Soft Contact Lens Material During Hydration

by Joseph Towler, Markus Zaplachinski, Roberto Montiel, Nikhil Murari, Christine Deng, Rimmo Lego, Arwa Fathy and Ahmed Abass

Gels 2025, 11(5), 376; https://doi.org/10.3390/gels11050376 - 21 May 2025

Cited by 2 | Viewed by 3027

Abstract

The aim of this study was to quantitatively evaluate the swelling and transparency behaviour of Contaflex soft contact lens materials with varying water-content (38–77%) using high-resolution digital imaging and infrared LiDAR. Contaflex materials with 38%, 55%, 58%, 67% and 77% nominal water-contents, denoted as C38, C55, C58, C67, and C77, were tested. Hydrogel samples (N = 5 per group) were monitored over 24 h in pH 7.1 phosphate-buffered saline. Dimensional changes were assessed via linear and radial expansion factors (LEF and REF), and transparency was tracked during hydration. All groups exhibited rapid initial swelling followed by continued expansion. LEF and REF values increased with water-content; C77 reached LEF and REF values of 1.563 ± 0.093 and 1.536 ± 0.052, while C38 stabilised near 1.201 ± 0.019 and 1.179 ± 0.011, respectively. Refractive index decreased with hydration, from 1.552 in C38 to 1.372 in C77. Power simulations revealed deviations beyond ISO tolerance limits in most materials, particularly those with higher water-content. Transparency changes were consistent with swelling dynamics. These findings support the need for material-specific design adjustments to account for hydration-related dimensional and optical changes in soft contact lenses. Full article

(This article belongs to the Special Issue Innovative Gels: Structure, Properties, and Emerging Applications)

► Show Figures

Graphical abstract

17 pages, 7093 KB

Open AccessArticle

Hydration Mechanism of Solid Waste Gelling Materials Containing Semi-Dry Desulfurization Ash

by Yunyun Li, Siqi Zhang, Meixiang Huang, Guodong Yang, Jiajie Li, Mengqi Ma, Wentao Hu and Wen Ni

Gels 2025, 11(3), 193; https://doi.org/10.3390/gels11030193 - 11 Mar 2025

Cited by 5 | Viewed by 1360

Abstract

This study investigated the feasibility of using semi-dry desulfurization ash (DA) in combination with blast furnace slag (BFS) to prepare gelling materials, aiming to improve the resource utilization of DA. The effects of DA dosage and mechanical grinding on the compressive strength and hydration mechanism of BFS-DA gelling materials were investigated. The results showed that the optimum BFS-DA ratio was 60:40, and the compressive strengths were 14.21 MPa, 20.24 MPa, 43.50 MPa, and 46.27 MPa at 3, 7, 28, and 56 days, respectively. Mechanical grinding greatly improved the activity of the gel materials, with the greatest increase in compressive strength at 3, 7, 28, and 90 days for the BFS and DA mixed milled for 30 min, with increases of 89.86%, 66.36%, 24.56%, and 25.68%, respectively, and compressive strength of 26.22 MPa, 35.6 MPa, 58.33 MPa, and 63.97 MPa, respectively. The cumulative heat of hydration of BFS-DA slurry was about 120 J/g. The hydration mechanism showed that the main hydration products formed were ettringite, C-S-H gel, AFm, and Friedel’s salt. Calcium sulfite in DA was participated in the hydration, and a new hydration product, Ca₄Al₂O₆SO₃·11H₂O, was formed. DA can be effectively used to prepare BFS-based gelling materials, and its performance meets the requirements of GB/T 28294-2024 standard, which provides a potential solution for the utilization of DA resources and the reduction in the impact on the environment. Full article

(This article belongs to the Special Issue Innovative Gels: Structure, Properties, and Emerging Applications)

► Show Figures

Figure 1

Review

Jump to: Research

39 pages, 1821 KB

Open AccessReview

Hydrogel Development, Processing and Applications in Agriculture: A Review

by Carmen Mª. Granados-Carrera, Victor M. Perez-Puyana, Mercedes Jiménez-Rosado and Alberto Romero

Gels 2026, 12(3), 259; https://doi.org/10.3390/gels12030259 - 20 Mar 2026

Viewed by 532

Abstract

Hydrogels have emerged as promising functional materials for improving water management and nutrient delivery in agriculture, particularly under conditions of increasing water scarcity and declining soil fertility. However, most commercially available superabsorbent hydrogels are based on petroleum-derived polymers, raising concerns regarding their persistence in soils, potential microplastic formation and long-term environmental impact. In response, significant research efforts are being directed toward the development of biodegradable hydrogels derived from renewable biopolymers. This review provides a critical overview of recent advances in hydrogel systems designed for agricultural applications, with a particular focus on biopolymer-based materials. First, the current landscape of hydrogel technologies used as soil conditioners and controlled-release systems for agrochemicals is contextualized, highlighting the limitations of conventional synthetic hydrogels. Subsequently, the main classes of natural polymers explored for hydrogel fabrication, including polysaccharides (e.g., chitosan, alginate, cellulose and starch) and proteins (e.g., gelatin, keratin and soy protein), are analyzed in terms of raw material sources, gelation mechanisms and structure–property relationships. Their performance in key agricultural functions, such as water retention, controlled nutrient release, soil conditioning and enhancement of plant growth, is also discussed. Finally, the review identifies major challenges that currently hinder large-scale implementation, including mechanical stability, degradation behavior in complex soil environments, nutrient release control and economic scalability. By integrating recent progress and outlining emerging research directions, this work aims to support the rational design of next-generation biodegradable hydrogels capable of contributing to sustainable agriculture and circular bioeconomy strategies. Full article

(This article belongs to the Special Issue Innovative Gels: Structure, Properties, and Emerging Applications)

► Show Figures

Graphical abstract

20 pages, 939 KB

Open AccessReview

Exploration of Natural Adsorbents for Applications in Pollution-Reducing Cosmetic Formulations

by Greta Kaspute, Alma Rucinskiene, Arunas Ramanavicius and Urte Prentice

Gels 2026, 12(3), 232; https://doi.org/10.3390/gels12030232 - 12 Mar 2026

Viewed by 604

Abstract

Human skin and hair act as multifunctional barriers but are highly sensitive to environmental pollutants originating from air, water, and cosmetic products. Epidemiological studies report that exposure to particulate matter (PM_2.5–PM₁₀), nitrogen oxides (NO_x), and volatile organic compounds increases the risk of skin and hair disorders. For instance, women in high-traffic areas (N = 211) show significantly more pigment spots and nasolabial wrinkles compared to those in rural areas (N = 189), indicating accelerated skin ageing. Children aged 9–11 exposed to PM₁₀, benzene, and NO_x exhibit increased incidence of atopic dermatitis. Systemic exposure to dioxins causes chloracne, while co-exposure to polycyclic aromatic hydrocarbons (PAHs) and UVA radiation elevates skin cancer risk. Psoriasis flares are associated with mean pollutant concentrations over the 60 days preceding flare events in 957 patients, and hyperpigmentation prevalence increases in populations exposed to traffic-related PM and ROS-inducing pollutants. Hair loss is linked to oxidative stress from PM and PAHs absorbed on hair fibers, with in vitro studies showing keratinocyte apoptosis in scalp hair follicles. This review evaluates natural adsorbents such as zeolites, clays, activated carbon, and polyphenol-rich plant extracts for anti-pollution cosmetic formulations. Adsorption capacities range from 60 to 150 mg·g⁻¹ depending on the pollutant, with removal efficiencies of 30–55% in model topical systems. Mechanisms include ion exchange, surface adsorption, hydrophobic interactions, and radical scavenging. Incorporating 2–5% w/w of these adsorbents in cosmetic formulations significantly reduces pollutant deposition on skin and hair. These findings support the development of evidence-based, sustainable anti-pollution cosmetic strategies that quantitatively mitigate environmental stressor effects. Full article

(This article belongs to the Special Issue Innovative Gels: Structure, Properties, and Emerging Applications)

► Show Figures

Graphical abstract

31 pages, 3530 KB

Open AccessReview

In Situ Forming Poloxamer-Based Thermo-Sensitive Hydrogels for Ocular Application: A Focus on the Derivatives 407 and 188

by Emanuela Longo, Elena Giuliano, Agnese Gagliardi, Valeria Gaetano, Marialaura Frisina, Mario Verdiglione and Donato Cosco

Gels 2025, 11(9), 752; https://doi.org/10.3390/gels11090752 - 17 Sep 2025

Cited by 7 | Viewed by 3594

Abstract

In ophthalmology, developing effective drug delivery systems is crucial to overcome anatomical and physiological barriers, such as rapid tear turnover and blinking, which limit the efficacy of conventional formulations like eye drops. Poloxamers, especially the derivatives 407 (P407) and 188, are amphiphilic triblock copolymers characterized by an intriguing thermo-reversible behavior, making them ideal candidates for the development of in situ hydrogels for ocular applications. Various thermo-sensitive poloxamer-based hydrogels were designed to be easily instilled as liquids at room temperature, gelling promptly upon contact with the corneal surface. These systems promoted a controlled release of active compounds, significantly improving their adhesion to the ocular surface. This review discusses the most relevant scientific literature on the topic, with particular attention to studies published in recent years. The results demonstrated that poloxamer formulations are capable of overcoming typical ocular barriers, thereby increasing drug bioavailability. The intrinsic biocompatibility of poloxamers contributes to the safety and tolerability of the system. Furthermore, P407 showed additional wound healing features. The combination of biocompatibility and thermo-reversible behavior makes poloxamer-based hydrogels a promising platform for the development of innovative ocular drug delivery systems able to enhance therapeutic efficacy and patient comfort. Full article

(This article belongs to the Special Issue Innovative Gels: Structure, Properties, and Emerging Applications)

► Show Figures

Journal Menu

Journal Browser

Innovative Gels: Structure, Properties, and Emerging Applications

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Related Special Issue

Published Papers (8 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI