Polymer Chemistry
·
2014
·Vol. 5
·期 22
·6489-6494
·
IF 5.368
Huan Wang,Guangyu Zha,Hong Du,Lilong Gao,Xiaodong Li,Zhiquan Shen,Weipu Zhu
We report a facile strategy to fabricate ultrathin hydrogel films via a layer-by-layer (LbL) technique and “click” chemistry. Poly[oligo(ethylene glycol)fumarate]-co-poly[dodecyl bis(2-hydroxyethyl)methylammonium fumarate] (POEGDMAM) containing multi-enes and poly[oligo(ethylene glycol)mercaptosuccinate] (POEGMS) containing multi-thiols were synthesized by polycondensation, which were used as precursors for a LbL thiol–ene “click” reaction under ambient conditions without any metal catalyst or light irradiation. Due to the presence of ammonium groups with long alkyl chains in the POEGDMAM, the ultrathin hydrogel films exhibited excellent antibacterial activity against both Staphylococcus aureus and Escherichia coli, which was enhanced by increasing the number of layers. These kinds of biocompatible, antibacterial, ultrathin hydrogel films are promising candidates for biomedical applications.
研究领域:
生物材料学
·
医学工程
·
高分子化学
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DOI
高影响因子
Polymer Chemistry
·
2019
·Vol. 10
·期 35
·4844-4851
·
IF 4.76
Yu Wang,Qianbing Chen,Mao Chen,Ying Guan,Yongjun Zhang
Swelling-induced mechanical instability is ubiquitous for substrate-attached hydrogel films, which results in a coarse surface and should be avoided in most applications. To test if the undesired instability patterns can be self-healed by the introduction of reversible covalent crosslinks, poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel films crosslinked with disulfide bonds were synthesized. 2-Acetylthioethyl methacrylate (ATEMA), a monomer containing a protected thiol group, was first synthesized from HEMA and thioacetic acid. Linear P(HEMA-ATEMA) copolymers were then synthesized by free-radical polymerization. To avoid the hydrolysis of ester bonds, the thioester protecting groups were cleaved by reaction with dithiothreitol in the presence of a catalytic amount of a base, and linear PHEMA polymers with pendant thiol groups, i.e., P(HEMA-MEMA) were obtained. PHEMA films crosslinked with disulfide bonds were obtained by exposing P(HEMA-MEMA) films to H2O2 vapor. Like ordinary hydrogel films, the crosslinked films also undergo mechanical instability when swelling in an ethanol/water mixture, because unidirectional expansion generates compressive stress within the film. Interestingly, the instability patterns could be self-healed, and the gel surface returned to be flat. In contrast, the instability patterns on a PHEMA film crosslinked with ordinary covalent bonds were permanent. The transient network in films crosslinked with dynamic disulfide bonds allows the relaxation of the swelling-induced compressive stress in the films, therefore, the undesired instability patterns can be self-healed.
研究领域:
材料科学
·
聚合物化学
·
软物质物理
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Yaqian Zhang,Min Zhang,Haoyang Jiang,Jinli Shi,Feibo Li,Yanhong Xia,Gongzheng Zhang,Huanjun Li
The layered nanocomposite hydrogel films containing chitosan (CS) and graphene oxide (GO) have been prepared by water evaporation induced self-assembly and subsequent physical cross-linking in alkaline solution. The layered CS/GO hydrogel films obtained have a nacre-like brick-and-mortar microstructure, which contributes to their excellent mechanical properties. The tensile strength and elongation at break of the hydrogel films with 5 wt% GO are 5.35 MPa and 193.5%, respectively, which are comparable to natural costal cartilage. Furthermore, the CS/GO hydrogel films exhibited pH-driven shape memory effect, and this unique phenomenon is mainly attributed to the reversible transition of partial physically cross-linking corresponding to hydrogen bondings and hydrophobic interactions between CS polymer chains due to pH changing.
研究领域:
材料科学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Qian Li,Ying Guan,Yongjun Zhang
Concanavalin A (Con A) has been widely used as glucose recognition element in glucose sensors, however, these sensors typically detect glucose by fluorescence, and suffer from laborious labeling processes. Here a new label-free optical Con A-based glucose sensor was designed. The sensor uses Con A-containing thin hydrogel films as sensing material and Fabry-Perot cavity simultaneously, which were fabricated by layer-by-layer assembly of Con A and dextran, using lectin-saccharide biospecific interaction as driving force. These films display Fabry-Perot fringes on their reflection spectra, from which optical path length of the films can be calculated. The films swell upon addition of glucose, which causes a shift of Fabry-Perot fringes on the reflection spectra of the film, from which the glucose concentration can be reported. The glucose-induced swelling is reversible, and the increase in optical path length increases linearly with glucose concentration over a wide range of glucose concentration. The sensor works well at physiological temperature, pH and ionic strength. Other sugars, which may present in blood, do not interfere with glucose detection, because of their very low concentrations in the blood. Particularly, unlike other hydrogel-based sensors, this sensor responds quite fast, because the hydrogel films are very thin. The new sensor may have potential for real time, continuous glucose monitoring.
研究领域:
生物传感
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材料科学
·
分析化学
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2014
·Vol. 5
·期 24
·7081-7089
·
IF 5.368
Lin Zhou,Mao Chen,Ying Guan,Yongjun Zhang
Stimuli-responsive hydrogels whose swelling degree changes in response to certain external stimulus are usually constructed by the introduction of a functional group. Here we show that they can also be constructed using dynamic bonds as crosslinks because the equilibrium of their formation and breakage can be shifted by external stimuli. As an example, hydrogel films were fabricated from partially oxidized dextran (PO-Dex) and chitosan (Chi) using the layer-by-layer assembly technique. The driving force for the film buildup is the in situ formation of Schiff base bonds between the aldehyde groups on PO-Dex and amino groups on Chi. The swelling of the film was studied using the Fabry–Perot fringes on the reflection spectra. Like ordinary hydrogels, the PO-Dex/Chi hydrogel films swell in water. Their swelling degree decreases with increasing oxidation degree of PO-Dex. The films swell to a larger degree when the pH is lowered. The pH-sensitivity was attributed to amino groups on chitosan and also the dynamic Schiff base linkages, because pH change shifts the equilibrium of the Schiff base reaction in the films, resulting in a change in the crosslink density and therefore a change in swelling degree. When the transient linkages were fixed by NaBH4 reduction, the pH-sensitivity of the films was significantly reduced. The films were found to be sensitive to other external stimuli, including temperature, L-lysine and pyridoxal. These stimuli-responsivities were also attributed to the dynamic Schiff base linkages in the film.
研究领域:
材料科学
·
生物化学
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DOI
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Guangna Feng,Kexin Li,Guangming Li,Zhenbang Zhang,Jiahong Xiang,Tao Chen,Feng Jiao,Haili Zhao
Responsive photonic crystal materials that can change their structural color in response to external stimuli have attracted growing attention in the research area of flexible electronics. This study presents a conductive structural color hydrogel film featuring an inverse opal structure designed for use in wearable sensors. The hydrogel film consists of a double-network structure, where the first network is formed by acrylic acid and acrylamide (P(AA-co-AM)), and the second network is composed of quaternized chitosan. By incorporating multiwall carbon nanotubes (MWCNTs) into the hydrogel, not only is the conductivity enhanced but also the tensile strength of the hydrogel is significantly improved (0.45 MPa). Due to the excellent stretchability and inverse opal architecture of the hydrogel matrix, the film exhibited vibrant and tunable structural colors in response to applied stress or strain. Leveraging these attributes, the hydrogel film not only visualized color changes but also provided feedback on electrical signals in response to strain or stress stimuli, thereby functioning as a dual-signal soft sensor for the real-time monitoring of optical and electrical signals related to human motion. In addition, the presence of chitosan, known for its excellent water absorption properties, allows the film to swell in water while shrinking in ethanol. This characteristic enables the film to quantitatively respond to ethanol through noticeable color changes. This work demonstrates a strategy of synergistic enhancement of the mechanical properties of hydrogels through a combination of MWCNTs and a double-network structure. The presented conductive structural color hydrogel film, featuring a dual-signal output, exhibits remarkable potential for applications in wearable devices and multifunctional sensors.
研究领域:
材料科学
·
柔性电子学
·
传感技术
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产品关联
DOI
高影响因子
ACS Applied Bio Materials
·
2024
·
IF 4.6
Xingli Ding,Li Sheng,Jianming Zhang,Ge Zhang,Qi Gu,Yu Li,Long Zhang,Min Ji
Portable fluorescent film sensors offer a solution to the contamination issue in homogeneous sensor detection systems. However, their special structure leads to low sensitivity and a long response time, resulting in a significant scientific challenge limiting their development and application. In this work, we propose a dual design strategy to prepare highly sensitive film sensors for rapidly detecting Cr2O72–. Specifically, P(Fmoc-Osu)-SA hydrogel films were developed by integrating the biological macromolecule sodium alginate (SA) with the conjugated polymer poly(N-(9-Fluorenylmethoxycarbonyloxy)succinimide) (P(Fmoc-Osu)), using both mold and inkjet 3D printing methods. The “molecular wire effect” of the sensing unit P(Fmoc-Osu) and the water channel within the film substrate are responsible for the improved sensitivity and the reduced response time of this thin film sensor. P(Fmoc-Osu)-SA hydrogel films prepared by these two methods can rapidly detect Cr2O72– with limits of detection of 1.18 and 0.078 nM, respectively. Considering that 3D-printed hydrogel films can be tailored to different shapes according to detection needs, the P(Fmoc-Osu)-SA hydrogel films produced from this method were effectively applied in vegetable samples. This study provides an innovative and effective strategy for the development of biocompatible hydrogel sensors that offer the potential for determining trace amounts of Cr2O72– in agriculture.
研究领域:
环境科学
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材料科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
LUMINESCENCE
·
2017
·Vol. 32
·期 6
·970-977
·
IF 1.509
Shujuan Yu,Kuan Chen,Feng Wang,Yongfei Zhu,Xuehong Zhang
A simple microwave-assisted solvothermal method was used to prepare fluorescent nitrogen-doped carbon dots (N-CDs) with high fluorescence quantum yield (79.63%) using citric acid and N -(2-hydroxyethyl)ethylenediamine as starting materials. The PVAm-g-N-CDs grafted products were synthesized by amide bond formation between the carboxylic groups of N-CDs and amine groups of polyvinylamine (PVAm). Fluorescent hydrogel films (PVAm-g-N-CDs/PAM) were synthesized by interpenetration polymer network polymerization of PVAm-g-N-CDs and acrylamide (AM). When used for ion detection, we found that the fluorescence of the hydrogel films was clearly quenched by addition of Hg 2+ . Repeatability tests on using the hydrogel films for Hg 2+ detection showed that they could be applied at least three times. The PVAm-g-N-CDs/PAM could serve as an effective fluorescent sensing platform for sensitive detection of Hg 2+ ions with a detection limit of 0.089 μmol/L. This work may offer a new approach for developing recoverable and sensitive N-CDs-based sensors for biological and environmental applications.
研究领域:
材料科学
·
环境科学
·
分析化学
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DOI
高影响因子
LANGMUIR
·
2018
·
IF 3.789
Ye Tian,Xiaoying Gao,Wei Hong,Miao Du,Pengju Pan,Jing Zhi Sun,Zi Liang Wu,Qiang Zheng
In a previous work (ACS Appl. Mater. Interfaces2017, 9, 34349–34355), a facile approach was reported to prepare thin hydrogel films based on the Marangoni effect. After dripping onto a water surface, a drop of ethanol solution of poly(stearyl acrylate-co-acrylic acid) [P(SA-co-AAc)] spread quickly to form a thin film. The solvent exchange from ethanol to water led to the gelation of polymer solution which turned into a hydrogel film. Here, we investigate the scenario and seek for the governing kinetics of the Marangoni effect-assisted preparation of hydrogel films. By incorporating aggregation-induced emission fluorogens into the P(SA-co-AAc) solution, so that fluorescence appears at the gel state, we found that the spreading usually completed before the full gelation of the entire film. The spreading and formation of the gel films were influenced by the molar fraction of SA, f, and the polymer concentration of ethanol solution, CP. The spreading was blocked when CP was too high, whereas the film was fragmented into small pieces when CP was too low. At an intermediate CP, uniform hydrogel films were obtained. Steady spreading at a constant speed was observed during the processes which yielded uniform hydrogel films. Both CP and f influenced the spreading process by tuning the surface tension of the ethanol solution and the viscoelasticity of the gelated film, as suggested by our theoretical model. This work provided kinetic insights into the Marangoni phenomena of viscous polymer solutions. The strategy and principle should be applicable to other systems on preparing thin supramolecular gel films with versatile functions.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 2
·140
·
IF 4.034
Wenjuan Li,Junhuai Xiang,Dandan Men,Honghua Zhang
A novel glucose sensor was reported that consisted of two-dimensional (2D) Au nanosphere arrays and glucose-responsive hydrogel film. This sensor exhibited an intense diffraction signal and an obvious diffraction color on a quartz slide due to the strong diffraction intensity of the Au nanosphere arrays. Thus, glucose was detected via the variation of diffraction wavelength and diffraction color, without a high reflective mirror. In addition, by introducing poly(vinyl alcohol) (PVA) to crosslink the phenylboronic acid (PBA)-modified hydrogel film, the diffraction wavelength of the 2D Au nanosphere arrays/hydrogel composite film shifted in the same direction in high ionic strength condition. In particular, it showed a nearly linear red-shift when the glucose concentration increased from 0 mM to 20 mM. Moreover, this glucose sensor displayed good reproducibility. The nearly linear response and good reproducibility were highly helpful for improving practical application of this glucose sensor.
研究领域:
生物医学工程
·
材料科学
·
分析化学
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2014
·
IF 3.916
Dengshan Bao,Mingjie Chen,Haiying Wang,Jufang Wang,Chuanfu Liu,Runcang Sun
A novel crosslinked hydrogel film was prepared from carboxymethylchitosan (CMCS) and carboxymethylcellulose (CMC) by ionical and covalent crosslinking with CaSO 4 and genipin, respectively. The swelling ratio of the crosslinked CMCS/CMC hydrogel films was investigated at different pH solutions (1–9), and the results indicated that the crosslinked hydrogels had the swelling–deswelling properties with two primary peaks of swelling ratio at pH 3 and 7. The surface morphologies of the crosslinked hydrogels at different pH values provided evidences of the swelling–deswelling properties. The mechanical properties of the hydrogel films were also examined. The ionical and covalent crosslinking were found to have the primary impact on the toughness and max load, respectively, of the crosslinked hydrogels. The cells comparatively cultured on the crosslinked hydrogels and the negative and positive controls suggested the biocompatibility of the crosslinked CMCS/CMC films. This kind of hydrogel films have potential application in drug delivery vehicles and skin tissue engineering.
研究领域:
材料科学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2016
·Vol. 4
·期 11
·2117-2122
·
IF 5.066
Dandan Men,Fei Zhou,Lifeng Hang,Xinyang Li,Guotao Duan,Weiping Cai,Yue Li
Free-standing 2D Au nanosphere array/hydrogel composite sensing films were prepared by attaching a 2D Au nanosphere array onto a polyacrylic acid (PAAc) hydrogel film, which could be used as visualized sensors. These 2D Au nanosphere array/hydrogel composite films displayed visually diffraction color and much stronger diffraction intensity due to their periodic structures and large scattering cross-section of the Au nanospheres. Their diffraction intensity was increased by more than one order of magnitude (88 times) compared to that of 2D PS sphere array/hydrogel composite films to external stimuli, which is useful for visual observation by the naked eye and further optical characterization. Such 2D Au nanosphere array/hydrogel composite films exhibit ultrahigh diffraction intensity for them to be used for the visual determination of an analyte. The presented strategy could be extended to develop different visualized sensors based on various functional hydrogel films.
研究领域:
材料科学
·
生物传感
·
光学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）