Polymers

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14 pages, 16070 KiB

Open AccessArticle

Mechanical Model for Super-Anisotropic Swelling of the Multi-Cylindrical PDGI/PAAm Gels

by Tasuku Nakajima, Kei Mito and Jian Ping Gong

Polymers 2023, 15(7), 1624; https://doi.org/10.3390/polym15071624 - 24 Mar 2023

Cited by 1 | Viewed by 1991

MC-PDGI/PAAm gels are cylindrical composite gels containing poly(dodecyl glyceryl itaconate) (PDGI) as a polymerized lipid oriented in a multilayer tubular shape within a polyacrylamide (PAAm) network. The most unique feature of the MC-PDGI/PAAm gel is its super-anisotropic swelling, wherein the diameter of the [...] Read more.

MC-PDGI/PAAm gels are cylindrical composite gels containing poly(dodecyl glyceryl itaconate) (PDGI) as a polymerized lipid oriented in a multilayer tubular shape within a polyacrylamide (PAAm) network. The most unique feature of the MC-PDGI/PAAm gel is its super-anisotropic swelling, wherein the diameter of the gel increases, but the length decreases with an increase in the volume of the gel. Through swelling and small-angle X-ray diffraction experiments, we investigated the effects of PDGI lipid bilayers and polymer network on the swelling of the MC-PDGI/PAAm gel, which suggests that the swelling anisotropy of the MC-PDGI/PAAm gel is dominated by the elasticity of the PDGI bilayers. Furthermore, we investigated the equation of state of the gel that roughly reproduced the experimental swelling results. These findings are crucial for realizing the controlled super-anisotropic swelling of MC-PDGI/PAAm gels and their applications as anisotropic actuation devices. Full article

(This article belongs to the Special Issue Advances in Multifunctional Hydrogel)

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27 pages, 12005 KiB

Open AccessArticle

Effect of Lanthanum Sorption on the Behavior of Rarely Crosslinked Acidic and Basic Polymer Hydrogels during Remote Interaction

by Yevgeniy Melnikov, Ruslan Kondaurov and Laura Agibayeva

Polymers 2023, 15(6), 1420; https://doi.org/10.3390/polym15061420 - 13 Mar 2023

Viewed by 1578

Abstract

This present study is targeted at the complex investigation of the behavior of interpolymer systems based on acidic rarely crosslinked polymeric hydrogels (polyacrylic acid hydrogel (hPAA); polymethacrylic acid hydrogel (hPMAA)) and basic rarely crosslinked polymeric hydrogels (poly-4-vinylpyridine hydrogel (hP4VP), specifically the poly-2-methyl-5-vinylpyridine hydrogel [...] Read more.

This present study is targeted at the complex investigation of the behavior of interpolymer systems based on acidic rarely crosslinked polymeric hydrogels (polyacrylic acid hydrogel (hPAA); polymethacrylic acid hydrogel (hPMAA)) and basic rarely crosslinked polymeric hydrogels (poly-4-vinylpyridine hydrogel (hP4VP), specifically the poly-2-methyl-5-vinylpyridine hydrogel (hP2M5VP)) either in an aqueous medium or lanthanum nitrate solution. We found that the transition of the polymeric hydrogels in the developed interpolymer systems (hPAA-hP4VP, hPMAA-hP4VP, hPAA-hP2M5VP, and hPMAA-hP2M5VP) into highly ionized states leads to significant changes in electrochemical, conformational, and sorption properties of the initial macromolecules. The subsequent mutual activation effect demonstrates strong swelling of both hydrogels in the systems. The sorption efficiency of lanthanum by the interpolymer systems is 94.51% (33%hPAA:67%hP4VP), 90.80% (17%hPMAA-83%hP4VP), 91.55% (67%hPAA:33%hP2M5VP), and 90.10% (50%hPMAA:50%hP2M5VP). An advantage of the interpolymer systems (compared to individual polymeric hydrogels) is the strong growth of their sorption properties (up to 35%) due to high ionization states. Interpolymer systems can be considered new-generation sorbents for further application in the industry for highly effective sorption of rare earth metals. Full article

(This article belongs to the Special Issue Advances in Multifunctional Hydrogel)

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12 pages, 14140 KiB

Open AccessArticle

Designing Multistimuli-Responsive Anisotropic Bilayer Hydrogel Actuators by Integrating LCST Phase Transition and Photochromic Isomerization

by Shijun Long, Jiacheng Huang, Jiaqiang Xiong, Chang Liu, Fan Chen, Jie Shen, Yiwan Huang and Xuefeng Li

Polymers 2023, 15(3), 786; https://doi.org/10.3390/polym15030786 - 3 Feb 2023

Cited by 7 | Viewed by 2281

Abstract

Stimuli-responsive hydrogel actuators have attracted tremendous interest in switches and microrobots. Based on N-isopropylacrylamide (NIPAM) monomers with LCST phase separation and photochromic molecule spiropyran which can respond to ultraviolet light and H+, we develop a novel multistimuli-responsive co-polymer anisotropic bilayer hydrogel, which [...] Read more.

Stimuli-responsive hydrogel actuators have attracted tremendous interest in switches and microrobots. Based on N-isopropylacrylamide (NIPAM) monomers with LCST phase separation and photochromic molecule spiropyran which can respond to ultraviolet light and H+, we develop a novel multistimuli-responsive co-polymer anisotropic bilayer hydrogel, which can undergo complex deformation behavior under environmental stimuli. Diverse bending angles were achieved based on inhomogeneous swelling. By controlling the environmental temperature, the bilayer hydrogels achieved bending angles of 83.4° and −162.4° below and above the critical temperature of PNIPAM. Stimulated by ultraviolet light and H+, the bilayer hydrogels showed bending angles of −19.4° and −17.3°, respectively. In addition, we designed a strategy to enhance the mechanical properties of the hydrogel via double network (DN). The mechanical properties and microscopic Fourier transform infrared (micro-FTIR) spectrum showed that the bilayer hydrogel can be well bonded at the interfaces of such bilayers. This work will inspire the design and fabrication of novel soft actuators with synergistic functions. Full article

(This article belongs to the Special Issue Advances in Multifunctional Hydrogel)

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12 pages, 1936 KiB

Open AccessArticle

A Tissue Paper/Hydrogel Composite Light-Responsive Biomimetic Actuator Fabricated by In Situ Polymerization

by Qijun Wu, Chao Ma, Lian Chen, Ye Sun, Xianshuo Wei, Chunxin Ma, Hongliang Zhao, Xiuling Yang, Xiaofan Ma, Chunmei Zhang and Gaigai Duan

Polymers 2022, 14(24), 5454; https://doi.org/10.3390/polym14245454 - 13 Dec 2022

Cited by 11 | Viewed by 2169

Abstract

Stimulus-responsive hydrogels are an important member of smart materials owing to their reversibility, soft/wet properties, and biocompatibility, which have a wide range of applications in the field of intelligent actuations. However, poor mechanical property and complicated fabrication process limit their further applications. Herein, [...] Read more.

Stimulus-responsive hydrogels are an important member of smart materials owing to their reversibility, soft/wet properties, and biocompatibility, which have a wide range of applications in the field of intelligent actuations. However, poor mechanical property and complicated fabrication process limit their further applications. Herein, we report a light-responsive tissue paper/hydrogel composite actuator which was developed by combining inkjet-printed tissue paper with poly(N-isopropylacrylamide) (PNIPAM) hydrogel through simple in situ polymerization. Due to the high strength of natural tissue paper and the strong interaction within the interface of the bilayer structure, the mechanical property of the composite actuator was highly enhanced, reaching 1.2 MPa of tensile strength. Furthermore, the light-responsive actuation of remote manipulation can be achieved because of the stamping graphite with high efficiency of photothermal conversion. Most importantly, we also made a few remotely controlled biomimetic actuating devices based on the near-infrared (NIR) light response of this composite actuator. This work provides a simple strategy for the construction of biomimetic anisotropic actuators and will inspire the exploration of new intelligent materials. Full article

(This article belongs to the Special Issue Advances in Multifunctional Hydrogel)

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14 pages, 5433 KiB

Open AccessArticle

Strong, Tough, and Adhesive Polyampholyte/Natural Fiber Composite Hydrogels

by Yongqi Yan, Longya Xiao, Qin Teng, Yuanyuan Jiang, Qin Deng, Xuefeng Li and Yiwan Huang

Polymers 2022, 14(22), 4984; https://doi.org/10.3390/polym14224984 - 17 Nov 2022

Cited by 4 | Viewed by 2026

Abstract

Hydrogels with high mechanical strength, good crack resistance, and good adhesion are highly desirable in various areas, such as soft electronics and wound dressing. Yet, these properties are usually mutually exclusive, so achieving such hydrogels is difficult. Herein, we fabricate a series of [...] Read more.

Hydrogels with high mechanical strength, good crack resistance, and good adhesion are highly desirable in various areas, such as soft electronics and wound dressing. Yet, these properties are usually mutually exclusive, so achieving such hydrogels is difficult. Herein, we fabricate a series of strong, tough, and adhesive composite hydrogels from polyampholyte (PA) gel reinforced by nonwoven cellulose-based fiber fabric (CF) via a simple composite strategy. In this strategy, CF could form a good interface with the relatively tough PA gel matrix, providing high load-bearing capability and good crack resistance for the composite gels. The relatively soft, sticky PA gel matrix could also provide a large effective contact area to achieve good adhesion. The effect of CF content on the mechanical and adhesion properties of composite gels is systematically studied. The optimized composite gel possesses 35.2 MPa of Young’s modulus, 4.3 MPa of tensile strength, 8.1 kJ m⁻² of tearing energy, 943 kPa of self-adhesive strength, and 1.4 kJ m⁻² of self-adhesive energy, which is 22.1, 2.3, 1.8, 6.0, and 4.2 times those of the gel matrix, respectively. The samples could also form good adhesion to diverse substrates. This work opens a simple route for fabricating strong, tough, and adhesive hydrogels. Full article

(This article belongs to the Special Issue Advances in Multifunctional Hydrogel)

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23 pages, 3324 KiB

Open AccessArticle

Synthesis, Application and Effect of Hybrid Nanocomposites Based on Hydrogel and Nanoclay in Cement-Mortars

by Adhemar Watanuki Filho, Ricardo Tokio Higuti, Marcia Regina de Moura and Fauze Ahmad Aouada

Polymers 2022, 14(21), 4564; https://doi.org/10.3390/polym14214564 - 27 Oct 2022

Cited by 2 | Viewed by 2154

Abstract

Hybrid nanocomposite hydrogels, as admixtures for internal curing of cementitious materials, have been widely studied. This study analyzes the effect of applying 0.5% (wt/wt cement) of pre-soaked hydrogels based on polyacrylamide, carboxymethylcellulose, and three different concentrations of Cloisite-Na⁺ (0, 10, and 20% [...] Read more.

Hybrid nanocomposite hydrogels, as admixtures for internal curing of cementitious materials, have been widely studied. This study analyzes the effect of applying 0.5% (wt/wt cement) of pre-soaked hydrogels based on polyacrylamide, carboxymethylcellulose, and three different concentrations of Cloisite-Na⁺ (0, 10, and 20% wt/wt) on the fresh and hardened properties of cementitious mortars. In general, all mortars with hydrogel decreased the consistency index, mainly M20, due to the high concentration of Cloisite-Na⁺ that modifies the release kinect of the hydrogel. The results showed a slight variation, with an overall average value of 99% water retention in all mortars. This behavior is due to the portion of hydrogel-mortars dosage water retained to reduce the availability of free water in the mixture because this amount of water is stored, a priori, within the polymer particles. At 28 d, the mortars produced with hydrogels containing 20% of nanoclay (M20) exhibit mechanical behavior similar to the reference mortar (M), which corroborates the percentage of voids found. Scanning electron microscope images confirm that the M and M20 mortars are uniform and possess few pores or microcracks. Thus, these hybrid hydrogels have the potential to be innovative materials for water control improvements in cementitious materials technology. Full article

(This article belongs to the Special Issue Advances in Multifunctional Hydrogel)

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25 pages, 3854 KiB

Open AccessArticle

Synthetic Thermo-Responsive Terpolymers as Tunable Scaffolds for Cell Culture Applications

by Gaby D. Lizana-Vasquez, Luis F. Arrieta-Viana, Janet Mendez-Vega, Aldo Acevedo and Madeline Torres-Lugo

Polymers 2022, 14(20), 4379; https://doi.org/10.3390/polym14204379 - 17 Oct 2022

Cited by 5 | Viewed by 2383

Abstract

The use of tailored synthetic hydrogels for in vitro tissue culture and biomanufacturing provides the advantage of mimicking the cell microenvironment without issues of batch-to-batch variability. To that end, this work focused on the design, characterization, and preliminary evaluation of thermo-responsive, transparent synthetic [...] Read more.

The use of tailored synthetic hydrogels for in vitro tissue culture and biomanufacturing provides the advantage of mimicking the cell microenvironment without issues of batch-to-batch variability. To that end, this work focused on the design, characterization, and preliminary evaluation of thermo-responsive, transparent synthetic terpolymers based on N-isopropylacrylamide, vinylphenylboronic acid, and polyethylene glycol for cell manufacturing and in vitro culture applications. Polymer physical properties were characterized by FT-IR, ¹H-NMR, DLS, rheology, and thermal-gravimetric analysis. Tested combinations provided polymers with a lower critical solution temperature (LCST) between 30 and 45 °C. Terpolymer elastic/shear modulus varied between 0.3 and 19.1 kPa at 37 °C. Cellular characterization indicated low cell cytotoxicity on NIH-3T3. Experiments with the ovarian cancer model SKOV-3 and Jurkat T cells showed the terpolymers’ capacity for cell encapsulation without interfering with staining or imaging protocols. In addition, cell growth and high levels of pluripotency demonstrated the capability of terpolymer to culture iPSCs. Characterization results confirmed a promising use of terpolymers as a tunable scaffold for cell culture applications. Full article

(This article belongs to the Special Issue Advances in Multifunctional Hydrogel)

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14 pages, 2412 KiB

Open AccessArticle

The Preparation of Anti-Ultraviolet Composite Films Based on Fish Gelatin and Sodium Alginate Incorporated with Mycosporine-like Amino Acids

by Jing Gan, Chenxia Guan, Xiaoyu Zhang, Lirong Sun, Qinling Zhang, Shihui Pan, Qian Zhang and Hao Chen

Polymers 2022, 14(15), 2980; https://doi.org/10.3390/polym14152980 - 22 Jul 2022

Cited by 4 | Viewed by 2291

Abstract

Mycosporine-like amino acids (MAAs) are ultraviolet-absorbing compounds and have antioxidant functions. In this paper, MAAs were added into fish gelatin/sodium alginate films as an anti-ultraviolet additive. The effects of 0–5% MAAs (w/w, MAAs/fish gelatin) on the physical properties, antioxidant properties, antibacterial [...] Read more.

Mycosporine-like amino acids (MAAs) are ultraviolet-absorbing compounds and have antioxidant functions. In this paper, MAAs were added into fish gelatin/sodium alginate films as an anti-ultraviolet additive. The effects of 0–5% MAAs (w/w, MAAs/fish gelatin) on the physical properties, antioxidant properties, antibacterial properties and anti-ultraviolet properties of fish gelatin/sodium alginate films were investigated. The results suggest that the content of the MAAs influenced the mechanical properties. The water content, swelling and water vapor permeability of the films were not altered with the addition of MAAs. In addition, the composite films showed effective antioxidant activity and antimicrobial activity. The incorporation of MAAs significantly improved the DPPH radical scavenging activity of the films from 35.77% to 46.61%. Moreover, the block ultraviolet rays’ ability was also greatly improved when the film mixed with the MAAs and when the value of the light transmission was 0.6% at 350 nm. Compared with the pure composite film, the growth of E. coli covered by the composite film with 3.75% and 5% MAAs exhibited the best survival rate. These results reveal that MAAs are a good film-forming substrate, and MAAs have good potential to prepare anti-ultraviolet active films and antioxidant active films for applications. Overall, this project provides a theoretical basis for the study of active composite films with anti-ultraviolet activities, and it provides new ideas for the application of MAAs. Full article

(This article belongs to the Special Issue Advances in Multifunctional Hydrogel)

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