Self-Healing Polymers, Proteins and Composites

A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Polymer Applications".

Deadline for manuscript submissions: closed (31 August 2023) | Viewed by 26905

Special Issue Editor


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Guest Editor
“Petru Poni” Institute of Macromolecular Chemistry of Romanian Academy, 41 A, Grigore Ghica Voda Alley, 700487 Iasi, Romania
Interests: thermodynamic and rheological approaches for polymer-containing systems; conformational characteristics of polymers in solution; viscoelastic behavior of macromolecules in different flow conditions; soft materials—solutions, suspensions, hydrogels; stimuli-responsive (bio)materials; porous membranes; self-assembling phenomena
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Special Issue Information

Dear Colleagues,

Self-healing is the remarkable ability of living organisms to repair their own damage by themselves. Inspired from nature, the great challenge now is to create and develop polymers and composites with high potential for self-healing, offering alternatives to the current options and moving toward materials with extended service lifetime for various applications. Most of these are innovative (bio)materials with excellent healing performance, such as ionomers, semiconductors, self-assembling systems, hydrogels, micro- and nanoparticles, coatings, films and membranes, capsules, vascular networks, shape memory or stimuli-induced self-healing materials, etc. They are able to spontaneously repair themselves after damage or degradation, recovering structural integrity and functionality by increasing the rate of healing versus the rate of damage.

For this Special Issue, we are looking for articles that illustrate the latest developments in polymers and polymer composites providing a healing response. The discussion can be focused on the following aspects (in addition to any other aspects related to the main topic).

  • The state-of-the-art of bio-inspired self-healing materials—lessons from nature for enhancing healing action and limitations for implementation;
  • New approaches for self-healing in polymers and their composites—intrinsic and extrinsic self-healing as well as molecular mechanisms and key concepts;
  • Characterization of self-healing polymers and materials—triggering and tuning self-healing behavior, recovery properties and assessment of healing, and healing efficiency;
  • Engineering self-healing smart (bio-nano)composite materials for various applications in healthcare (hydrogels for tissue engineering and regenerative medicine, smart drug-delivery systems, etc.), sensors and actuators, coatings, biomimetics, electronics, self-cleaning textiles, bio-inspired robotics, dental composites, polymer-modified concrete, resins and fiber-reinforced resins, concrete and cementitious composites, automotive industry, aerospace engineering, etc.;
  • Self-healing polymer systems as smart materials of the future.

 

Original research contributions, short communications, discussions of challenges and opportunities, as well as review articles are all welcome.

 

Dr. Maria Bercea
Guest Editor

Manuscript Submission Information

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Keywords

  • intrinsic or extrinsic self-healing
  • hydrogels
  • reversible bond formation
  • noncovalent or/and covalent interactions
  • host–guest interactions
  • colloidal composites
  • stimuli-responsive polymers
  • biomimetics
  • healing agents
  • self-repairing
  • self-restoring
  • self-cleaning
  • multiple healing cycles
  • viscoelasticity
  • continuous step strain measurement
  • stress–strain curves
  • structure recovery
  • dynamic network

Published Papers (12 papers)

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Research

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14 pages, 3219 KiB  
Article
Evidence through Thermal Analysis of Retro Diels-Alder Reaction in Model Networks Based on Anthracene Modified Polyester Resins
by Daniela Ionita, Mariana Cristea, Constantin Gaina, Mihaela Silion and Bogdan C. Simionescu
Polymers 2023, 15(19), 4028; https://doi.org/10.3390/polym15194028 - 9 Oct 2023
Viewed by 972
Abstract
The present work is focused on polyester resins obtained from the diglycidyl ether of bisphenol A and anthracene modified 5-maleimidoisophthalic acid. Because the maleimide-anthracene Diels–Alder (DA) adduct is stable at high temperatures, it is considered a good option for high performance polymers. However, [...] Read more.
The present work is focused on polyester resins obtained from the diglycidyl ether of bisphenol A and anthracene modified 5-maleimidoisophthalic acid. Because the maleimide-anthracene Diels–Alder (DA) adduct is stable at high temperatures, it is considered a good option for high performance polymers. However, the information related to the retroDA reaction for this type of adduct is sometimes incoherent. A detailed thermal study (conventional TGA, HiRes TGA, MTGA, DSC, MDSC) was performed in order to establish whether the rDA reaction can be revealed for this type of anthracene modified polyester resins. The TGA method confirmed the cleavage of the anthracene–maleimide DA adduct, while the DSC demonstrated the presence of anthracene in the system. At high temperatures, unprotected maleimide homopolymerizes and/or reacts with allyl groups according to the –ene reaction. Therefore, the thermal DA reaction is not displayed anymore upon the subsequent cooling, and the glass transition region is registered at a higher temperature range during the second heating. The use of sample-controlled thermal analysis (HiRes TGA) and MTGA improved the TGA result; however, it was not possible to separate the very complex degradation processes that are interconnected. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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21 pages, 5079 KiB  
Article
Poloxamer/Carboxymethyl Pullulan Aqueous Systems—Miscibility and Thermogelation Studies Using Viscometry, Rheology and Dynamic Light Scattering
by Irina Popescu, Marieta Constantin, Maria Bercea, Bogdan-Paul Coșman, Dana Mihaela Suflet and Gheorghe Fundueanu
Polymers 2023, 15(8), 1909; https://doi.org/10.3390/polym15081909 - 16 Apr 2023
Cited by 4 | Viewed by 1463
Abstract
Thermally-induced gelling systems based on Poloxamer 407 (PL) and polysaccharides are known for their biomedical applications; however, phase separation frequently occurs in mixtures of poloxamer and neutral polysaccharides. In the present paper, the carboxymethyl pullulan (CMP) (here synthesized) was proposed for compatibilization with [...] Read more.
Thermally-induced gelling systems based on Poloxamer 407 (PL) and polysaccharides are known for their biomedical applications; however, phase separation frequently occurs in mixtures of poloxamer and neutral polysaccharides. In the present paper, the carboxymethyl pullulan (CMP) (here synthesized) was proposed for compatibilization with poloxamer (PL). The miscibility between PL and CMP in dilute aqueous solution was studied by capillary viscometry. CMP with substitution degrees higher than 0.5 proved to be compatible with PL. The thermogelation of concentrated PL solutions (17%) in the presence of CMP was monitored by the tube inversion method, texture analysis and rheology. The micellization and gelation of PL in the absence or in the presence of CMP were also studied by dynamic light scattering. The critical micelle temperature and sol–gel transition temperature decrease with the addition of CMP, but the concentration of CMP has a peculiar influence on the rheological parameters of the gels. In fact, low concentrations of CMP decrease the gel strength. With a further increase in polyelectrolyte concentration, the gel strength increases until 1% CMP, then the rheological parameters are lowered again. At 37 °C, the gels are able to recover the initial network structure after high deformations, showing a reversible healing process. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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22 pages, 9999 KiB  
Article
Development of Polyurethane/Peptide-Based Carriers with Self-Healing Properties
by Luiza Madalina Gradinaru, Maria Bercea, Alexandra Lupu and Vasile Robert Gradinaru
Polymers 2023, 15(7), 1697; https://doi.org/10.3390/polym15071697 - 29 Mar 2023
Cited by 5 | Viewed by 1710
Abstract
In situ-forming gels with self-assembling and self-healing properties are materials of high interest for various biomedical applications, especially for drug delivery systems and tissue regeneration. The main goal of this research was the development of an innovative gel carrier based on dynamic inter- [...] Read more.
In situ-forming gels with self-assembling and self-healing properties are materials of high interest for various biomedical applications, especially for drug delivery systems and tissue regeneration. The main goal of this research was the development of an innovative gel carrier based on dynamic inter- and intramolecular interactions between amphiphilic polyurethane and peptide structures. The polyurethane architecture was adapted to achieve the desired amphiphilicity for self-assembly into an aqueous solution and to facilitate an array of connections with peptides through physical interactions, such as hydrophobic interactions, dipole-dipole, electrostatic, π–π stacking, or hydrogen bonds. The mechanism of the gelation process and the macromolecular conformation in water were evaluated with DLS, ATR-FTIR, and rheological measurements at room and body temperatures. The DLS measurements revealed a bimodal distribution of small (~30–40 nm) and large (~300–400 nm) hydrodynamic diameters of micelles/aggregates at 25 °C for all samples. The increase in the peptide content led to a monomodal distribution of the peaks at 37 °C (~25 nm for the sample with the highest content of peptide). The sol–gel transition occurs very quickly for all samples (within 20–30 s), but the equilibrium state of the gel structure is reached after 1 h in absence of peptide and required more time as the content of peptide increases. Moreover, this system presented self-healing properties, as was revealed by rheological measurements. In the presence of peptide, the structure recovery after each cycle of deformation is a time-dependent process, the recovery is complete after about 300 s. Thus, the addition of the peptide enhanced the polymer chain entanglement through intermolecular interactions, leading to the preparation of a well-defined gel carrier. Undoubtedly, this type of polyurethane/peptide-based carrier, displaying a sol–gel transition at a biologically relevant temperature and enhanced viscoelastic properties, is of great interest in the development of medical devices for minimally invasive procedures or precision medicine. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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20 pages, 2998 KiB  
Article
Sustainable Multi-Network Cationic Cryogels for High-Efficiency Removal of Hazardous Oxyanions from Aqueous Solutions
by Ecaterina Stela Dragan, Doina Humelnicu and Maria Valentina Dinu
Polymers 2023, 15(4), 885; https://doi.org/10.3390/polym15040885 - 10 Feb 2023
Cited by 3 | Viewed by 1074
Abstract
It is still a challenge to develop advanced materials able to simultaneously remove more than one pollutant. Exclusive cationic composite double- and triple-network cryogels, with adequate sustainability in the removal of Cr2O72− and H2PO4 oxyanions, [...] Read more.
It is still a challenge to develop advanced materials able to simultaneously remove more than one pollutant. Exclusive cationic composite double- and triple-network cryogels, with adequate sustainability in the removal of Cr2O72− and H2PO4 oxyanions, were developed in this work starting from single-network (SN) sponges. Chitosan (CS), as the only polycation originating from renewable resources, and poly(N,N-dimethylaminoethylmethacrylate) (PDMAEMA) and polyethyleneimine (PEI), as synthetic polycations, were employed to construct multi-network cationic composite cryogels. The properties of the composites were tailored by the cross-linking degree of the first network (SN5 and SN20, which means CS with 5 or 20 mole % of glutaraldehyde, respectively) and by the order of the successive networks. FTIR, SEM-EDX, equilibrium water content and compressive tests were used in the exhaustive characterization of these polymeric composites. The sorption performances towards Cr2O72− and H2PO4 anions were evaluated in batch mode. The pseudo-first-order, pseudo-second-order (PSO) and Elovich kinetics models, and the Langmuir, Freundlich and Sips isotherm models were used to interpret the experimental results. The adsorption data were the best fitted by the PSO kinetic model and by the Sips isotherm model, indicating that the sorption mechanism was mainly controlled by chemisorption, irrespective of the structure and number of networks. The maximum sorption capacity for both oxyanions increased with the increase in the number of networks, the highest values being found for the multi-network sponges having SN5 cryogel as the first network. In binary systems, all sorbents preferred Cr2O72− ions, the selectivity coefficient being the highest for TN sponges. The high sorption capacity and remarkable reusability, with only a 4–6% drop in the sorption capacity after five sorption–desorption cycles, recommend these composite cryogels in the removal of two of the most dangerous pollutants represented by Cr2O72− and H2PO4. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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20 pages, 8117 KiB  
Article
Structure-Bioactivity Relationship of the Functionalized Polysulfone with Triethylphosphonium Pendant Groups: Perspective for Biomedical Applications
by Adina Maria Dobos, Adriana Popa, Cristina Mihaela Rimbu and Anca Filimon
Polymers 2023, 15(4), 877; https://doi.org/10.3390/polym15040877 - 10 Feb 2023
Viewed by 1324
Abstract
Development of new biomaterials based on polysulfones tailored to act in various biomedical fields represents a promising strategy which provides an opportunity for enhancing the diagnosis, prevention, and treatment of specific illnesses. To meet these requirements, structural modification of the polysulfones is essential. [...] Read more.
Development of new biomaterials based on polysulfones tailored to act in various biomedical fields represents a promising strategy which provides an opportunity for enhancing the diagnosis, prevention, and treatment of specific illnesses. To meet these requirements, structural modification of the polysulfones is essential. In this context, for design of new materials with long-term stability, enhanced workability, compatibility with biological materials and good antimicrobial activity, the functionalization of chloromethylated polysulfones with triethylphosphonium pendant groups (PSFEtP+) was adopted. The surface chemistry analysis (Fourier transform infrared spectroscopy (FTIR), Energy-dispersive X-ray spectroscopy (EDX)), rheological properties, morphological aspects (Scanning electron microscopy (SEM), polarized light microscopy (POM)), and antimicrobial activity of the synthetized polysulfone were investigated to establish the relationship between its structure and properties, as an important indicator for targeted applications. Based on the obtained features, evaluated by the relationship between the rheological properties and microstructural aspects, and also the response at the biomaterial-bacteria interface, these qualities have been confirmed in their performance, in terms of thermal stability, antimicrobial activity, and also an increase in lifetime. Consequently, derived results constitute the preliminary basis for future tests concerning their functionality as gel matrices in biomedical devices. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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19 pages, 5798 KiB  
Article
Enzymatically-Crosslinked Gelatin Hydrogels with Nanostructured Architecture and Self-Healing Performance for Potential Use as Wound Dressings
by Alina Gabriela Rusu, Loredana Elena Nita, Natalia Simionescu, Alina Ghilan, Aurica P. Chiriac and Liliana Mititelu-Tartau
Polymers 2023, 15(3), 780; https://doi.org/10.3390/polym15030780 - 3 Feb 2023
Cited by 5 | Viewed by 2032
Abstract
Development of natural protein-based hydrogels with self-healing performance and tunable physical properties has attracted increased attention owing to their wide potential not only in the pharmaceutical field, but also in wounds management. This work reports the development of a versatile hydrogel based on [...] Read more.
Development of natural protein-based hydrogels with self-healing performance and tunable physical properties has attracted increased attention owing to their wide potential not only in the pharmaceutical field, but also in wounds management. This work reports the development of a versatile hydrogel based on enzymatically-crosslinked gelatin and nanogels loaded with amoxicillin (Amox), an antibiotic used in wound infections. The transglutaminase (TGase)-crosslinked hydrogels and encapsulating nanogels were formed rapidly through enzymatic crosslinking and self-assembly interactions in mild conditions. The nanogels formed through the self-assemble of maleoyl-chitosan (MAC5) and polyaspartic acid (PAS) may have positive influence on the self-healing capacity and drug distribution within the hydrogel network through the interactions established between gelatin and gel-like nanocarriers. The physicochemical properties of the enzymatically-crosslinked hydrogels, such as internal structure, swelling and degradation behavior, were studied. In addition, the Amox release studies indicated a rapid release when the pH of the medium decreased, which represents a favorable characteristic for use in the healing of infected wounds. It was further observed through the in vitro and in vivo biocompatibility assays that the optimized scaffolds have great potential to be used as wound dressings. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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15 pages, 5456 KiB  
Article
Injectable Networks Based on a Hybrid Synthetic/Natural Polymer Gel and Self-Assembling Peptides Functioning as Reinforcing Fillers
by Alina Ghilan, Alexandra Croitoriu, Aurica P. Chiriac, Loredana Elena Nita, Maria Bercea and Alina Gabriela Rusu
Polymers 2023, 15(3), 636; https://doi.org/10.3390/polym15030636 - 26 Jan 2023
Cited by 2 | Viewed by 1720
Abstract
Double network (DN) hydrogels composed of self-assembling low-molecular-weight gelators and a hybrid polymer network are of particular interest for many emerging biomedical applications, such as tissue regeneration and drug delivery. The major benefits of these structures are their distinct mechanical properties as well [...] Read more.
Double network (DN) hydrogels composed of self-assembling low-molecular-weight gelators and a hybrid polymer network are of particular interest for many emerging biomedical applications, such as tissue regeneration and drug delivery. The major benefits of these structures are their distinct mechanical properties as well as their ability to mimic the hierarchical features of the extracellular matrix. Herein, we describe a hybrid synthetic/natural polymer gel that acts as the initial network based on sodium alginate and a copolymer, namely poly(itaconic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro (5,5) undecane). The addition of amino acids and peptide-derived hydrogelators, such as Fmoc-Lys-Fmoc-OH and Fmoc-Gly-Gly-Gly-OH, to the already-made network gives rise to DNs crosslinked via non-covalent interactions. Fourier transform infrared spectroscopy (FTIR) and thermal analysis confirmed the formation of the DN and highlighted the interactions between the two component networks. Swelling studies revealed that the materials have an excellent water absorption capacity and can be classified as superabsorbent gels. The rheological properties were systematically investigated in response to different variables and showed that the prepared materials present injectability and a self-healing ability. SEM analysis revealed a morphology consisting of a highly porous and interconnected fibrous network. Finally, the biocompatibility was evaluated using the MTT assay on dermal fibroblasts, and the results indicated that the new structures are non-toxic and potentially useful for biomedical applications. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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19 pages, 5634 KiB  
Article
Influence of the Prepolymer Type and Synthesis Parameters on Self-Healing Anticorrosion Properties of Composite Coatings Containing Isophorone Diisocyanate-Loaded Polyurethane Microcapsules
by Matic Šobak, Danaja Štular, Žiga Štirn, Gregor Žitko, Nataša Čelan Korošin and Ivan Jerman
Polymers 2021, 13(5), 840; https://doi.org/10.3390/polym13050840 - 9 Mar 2021
Cited by 6 | Viewed by 4097
Abstract
Self-healing anticorrosion composite coatings containing isophorone diisocyanate-loaded polyurethane microcapsules were developed, and comprehensive research on prepolymer and microcapsules synthesis, as well as functional composite coatings preparation and characterization, was performed. The influence of the prepolymer type and the concentration of the stabilizing agent [...] Read more.
Self-healing anticorrosion composite coatings containing isophorone diisocyanate-loaded polyurethane microcapsules were developed, and comprehensive research on prepolymer and microcapsules synthesis, as well as functional composite coatings preparation and characterization, was performed. The influence of the prepolymer type and the concentration of the stabilizing agent used in the synthesis procedure on the properties of the microcapsules was studied in detail. For this purpose, three different prepolymers were prepared from toluene-2,4-diisocyanate (TDI) and either glycerol, 1,4-butanediol, or 1,6-hexanediol, and their chemical properties were investigated. Microcapsules were synthesized from the obtained prepolymers, according to the oil-in-water polymerization method, where 1,6-hexanediol was used as a chain extender, while the concentration of the stabilizing agent in the synthesis procedure was varied. Microcapsules prepared from TDI-glycerol prepolymer, synthesized in the presence of 10 wt% of the stabilizing agent, showed superior chemical, morphological, and thermo-gravimetrical properties; thus, they were incorporated into the coating in the concentration of 20 wt%. The prepared composite coatings demonstrated self-healing and anticorrosion properties, and thus the developed microcapsules show great potential for the incorporation into the composite anticorrosion coatings at critical points where damage can easily occur, providing longer and more efficient anticorrosion protection. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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14 pages, 2999 KiB  
Article
Global Sensitivity Analysis for the Polymeric Microcapsules in Self-Healing Cementitious Composites
by Shuai Zhou, Yue Jia and Chong Wang
Polymers 2020, 12(12), 2990; https://doi.org/10.3390/polym12122990 - 15 Dec 2020
Cited by 14 | Viewed by 1839
Abstract
Cementitious composites with microencapsulated healing agents are appealing due to the advantages of self-healing. The polymeric shell and polymeric healing agents in microcapsules have been proven effective in self-healing, while these microcapsules decrease the effective elastic properties of cementitious composites before self-healing happens. [...] Read more.
Cementitious composites with microencapsulated healing agents are appealing due to the advantages of self-healing. The polymeric shell and polymeric healing agents in microcapsules have been proven effective in self-healing, while these microcapsules decrease the effective elastic properties of cementitious composites before self-healing happens. The reduction of effective elastic properties can be evaluated by micromechanics. The substantial complicacy included in micromechanical models leads to the need of specifying a large number of parameters and inputs. Meanwhile, there are nonlinearities in input–output relationships. Hence, it is a prerequisite to know the sensitivity of the models. A micromechanical model which can evaluate the effective properties of the microcapsule-contained cementitious material is proposed. Subsequently, a quantitative global sensitivity analysis technique, the Extended Fourier Amplitude Sensitivity Test (EFAST), is applied to identify which parameters are required for knowledge improvement to achieve the desired level of confidence in the results. Sensitivity indices for first-order effects are computed. Results show the volume fraction of microcapsules is the most important factor which influences the effective properties of self-healing cementitious composites before self-healing. The influence of interfacial properties cannot be neglected. The research sheds new light on the influence of parameters on microcapsule-contained self-healing composites. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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Review

Jump to: Research

25 pages, 2433 KiB  
Review
Role of Hydrophobic Associations in Self-Healing Hydrogels Based on Amphiphilic Polysaccharides
by Marieta Nichifor
Polymers 2023, 15(5), 1065; https://doi.org/10.3390/polym15051065 - 21 Feb 2023
Cited by 10 | Viewed by 2330
Abstract
Self-healing hydrogels have the ability to recover their original properties after the action of an external stress, due to presence in their structure of reversible chemical or physical cross-links. The physical cross-links lead to supramolecular hydrogels stabilized by hydrogen bonds, hydrophobic associations, electrostatic [...] Read more.
Self-healing hydrogels have the ability to recover their original properties after the action of an external stress, due to presence in their structure of reversible chemical or physical cross-links. The physical cross-links lead to supramolecular hydrogels stabilized by hydrogen bonds, hydrophobic associations, electrostatic interactions, or host-guest interactions. Hydrophobic associations of amphiphilic polymers can provide self-healing hydrogels with good mechanical properties, and can also add more functionalities to these hydrogels by creating hydrophobic microdomains inside the hydrogels. This review highlights the main general advantages brought by hydrophobic associations in the design of self-healing hydrogels, with a focus on hydrogels based on biocompatible and biodegradable amphiphilic polysaccharides. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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26 pages, 6277 KiB  
Review
Advances in the Design of Phenylboronic Acid-Based Glucose-Sensitive Hydrogels
by Simona Morariu
Polymers 2023, 15(3), 582; https://doi.org/10.3390/polym15030582 - 23 Jan 2023
Cited by 9 | Viewed by 3475
Abstract
Diabetes, characterized by an uncontrolled blood glucose level, is the main cause of blindness, heart attack, stroke, and lower limb amputation. Glucose-sensitive hydrogels able to release hypoglycemic drugs (such as insulin) as a response to the increase of the glucose level are of [...] Read more.
Diabetes, characterized by an uncontrolled blood glucose level, is the main cause of blindness, heart attack, stroke, and lower limb amputation. Glucose-sensitive hydrogels able to release hypoglycemic drugs (such as insulin) as a response to the increase of the glucose level are of interest for researchers, considering the large number of diabetes patients in the world (537 million in 2021, reported by the International Diabetes Federation). Considering the current growth, it is estimated that, up to 2045, the number of people with diabetes will increase to 783 million. The present work reviews the recent developments on the hydrogels based on phenylboronic acid and its derivatives, with sensitivity to glucose, which can be suitable candidates for the design of insulin delivery systems. After a brief presentation of the dynamic covalent bonds, the design of glucose-responsive hydrogels, the mechanism by which the hypoglycemic drug release is achieved, and their self-healing capacity are presented and discussed. Finally, the conclusions and the main aspects that should be addressed in future research are shown. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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88 pages, 39533 KiB  
Review
Recent Advances in Limiting Fatigue Damage Accumulation Induced by Self-Heating in Polymer–Matrix Composites
by Jafar Amraei and Andrzej Katunin
Polymers 2022, 14(24), 5384; https://doi.org/10.3390/polym14245384 - 9 Dec 2022
Cited by 8 | Viewed by 3058
Abstract
The self-heating effect can be considered as a catastrophic phenomenon that occurs in polymers and polymer–matrix composites (PMCs) subjected to fatigue loading or vibrations. This phenomenon appears in the form of temperature growth in such structures due to their relatively low thermal conductivities. [...] Read more.
The self-heating effect can be considered as a catastrophic phenomenon that occurs in polymers and polymer–matrix composites (PMCs) subjected to fatigue loading or vibrations. This phenomenon appears in the form of temperature growth in such structures due to their relatively low thermal conductivities. The appearance of thermal stress resulting from temperature growth and the coefficient of thermal expansion (CTE) mismatch between fibers and neighboring polymer matrix initiates and/or accelerates structural degradation and consequently provokes sudden fatigue failure in the structures. Therefore, it is of primary significance for a number of practical applications to first characterize the degradation mechanism at the nano-, micro- and macroscales caused by the self-heating phenomenon and then minimize it through the implementation of numerous approaches. One viable solution is to cool the surfaces of considered structures using various cooling scenarios, such as environmental and operational factors, linked with convection, contributing to enhancing heat removal through convection. Furthermore, if materials are appropriately selected regarding their thermomechanical properties involving thermal conductivity, structural degradation may be prevented or at least minimized. This article presents a benchmarking survey of the conducted research studies associated with the fatigue performance of cyclically loaded PMC structures and an analysis of possible solutions to avoid structural degradation caused by the self-heating effect. Full article
(This article belongs to the Special Issue Self-Healing Polymers, Proteins and Composites)
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