共查询到20条相似文献，搜索用时 15 毫秒
1.
Daniel J. Hutchinson Viktor Granskog Johanna von Kieseritzky Henrik Alfort Patrik Stenlund Yuning Zhang Marianne Arner Joakim Håkansson Michael Malkoch 《Advanced functional materials》2021,31(41):2105187
Open reduction internal fixation (ORIF) metal plates provide exceptional support for unstable bone fractures; however, they often result in debilitating soft-tissue adhesions and their rigid shape cannot be easily customized by surgeons. In this work, a surgically feasible ORIF methodology, called AdhFix, is developed by combining screws with polymer/hydroxyapatite composites, which are applied and shaped in situ before being rapidly cured on demand via high-energy visible-light-induced thiol–ene coupling chemistry. The method is developed on porcine metacarpals with transverse and multifragmented fractures, resulting in strong and stable fixations with a bending rigidity of 0.28 (0.03) N m2 and a maximum load before break of 220 (15) N. Evaluations on human cadaver hands with proximal phalanx fractures show that AdhFix withstands the forces from finger flexing exercises, while short- and long-term in vivo rat femur fracture models show that AdhFix successfully supports bone healing without degradation, adverse effects, or soft-tissue adhesions. This procedure represents a radical new approach to fracture fixation, which grants surgeons unparalleled customizability and does not result in soft-tissue adhesions. 相似文献
2.
Xiao‐Hua Qin Krystyna Labuda Jie Chen Veronika Hruschka Anna Khadem Robert Liska Heinz Redl Paul Slezak 《Advanced functional materials》2015,25(42):6606-6617
Several hemostatic strategies rely on the use of blood components such as fibrinogen and thrombin, which suffer from high cost and short shelf‐life. Here, a cost‐effective synthetic biomaterial is developed for rapid local hemostasis. Instead of using thrombin, thrombin‐receptor‐agonist‐peptide‐6 (TRAP6) is covalently engineered in polyvinyl alcohol (PVA) hydrogels. Soluble PVA‐TRAP6 is first prepared by covalent attachment of cysteine‐containing TRAP6 onto the backbone of PVA‐norbornenes (PVA‐NB) through photoconjugation. Cytotoxicity studies using C2C12 myoblasts indicate that PVA‐NB and PVA‐TRAP6 are nontoxic. Thromboelastography reveals that hemostatic activity of TRAP6 is retained in conjugated form, which is comparable to free TRAP6 solutions with equal concentrations. A 0.1% PVA‐TRAP6 solution can shorten the clotting time (CT) to ca. 45% of the physiological CT. High platelet‐activating efficiency is further confirmed by platelet aggregation assay and flow cytometry (FACS). For potential clinical applications, TRAP6‐presenting hydrogel particulates (PVA‐TRAP6‐P) are developed for local platelet activation and hemostasis. PVA‐TRAP6‐P is prepared by biofunctionalization of photopolymerized PVA‐NB hydrogel particulates (PVA‐NB‐P) with TRAP6. It is demonstrated that PVA‐TRAP6‐P can effectively shorten the CT to ca. 50%. FACS shows that PVA‐TRAP6‐P can activate platelets to a comparable extent as soluble TRAP6 control. Altogether, PVA‐TRAP6‐P represents a promising class of biomaterials for safe hemostasis and wound healing. 相似文献
3.
Devatha P. Nair Neil B. Cramer John C. Gaipa Matthew K. McBride Emily M. Matherly Robert R. McLeod Robin Shandas Christopher N. Bowman 《Advanced functional materials》2012,22(7):1502-1510
There are distinct advantages to designing polymer systems that afford two distinct sets of material properties– an intermediate polymer that would enable optimum handling and processing of the material, while maintaining the ability to tune in different, final polymer properties that enable the optimal functioning of the material. In this study, by designing a series of non‐stoichiometric thiol‐acrylate systems, a polymer network is initially formed via a base catalyzed Michael addition reaction that proceeds stoichiometrically via the thiol‐acrylate “click” reaction. This self‐limiting reaction results in a polymer with excess acrylic functional groups within the network. At a later point in time, the photoinitiated, free radical polymerization of the excess acrylic functional groups results in a highly crosslinked, robust material system. These two stage reactive thiol‐acrylate networks that have intermediate stage rubbery moduli and glass transition temperatures that range from 0.5 MPa and ‐10 °C to 22 MPa and 22 °C, respectively, are formulated and characterized. The same polymer networks can then attain glass transition temperatures that range from 5 °C to 195 °C and rubbery moduli of up to 200 MPa after the subsequent photocuring stage. The two stage reactive networks formed by varying the stoichiometric ratios of the thiol and acrylate monomers were shown to perform as substrates for three specific applications: shape memory polymers, impression materials, and as optical materials for writing refractive index patterns. 相似文献
4.
Zhongxiang Bai Kun Jia Chenchen Liu Lingling Wang Guo Lin Yumin Huang Shuning Liu Xiaobo Liu 《Advanced functional materials》2021,31(49):2104701
Hydrogel modified porous matrix with the super-wetting surface (i.e., super-hydrophilic/underwater super-oleophobic) is ideal for oil/water separation. However, the deterioration in mechanical strength and separation efficiency during the swelling process and complicated synthesis procedure limits its industrial application. In this study, a strategy of using ethanol to dynamically regulate the hydrogen bond crosslinking between polyvinyl alcohol (PVA) and tannic acid (TA) is proposed to prepare a “hydrogel paint”, which can be simply applied on the porous substrate surface by different one-step operations (dipping, brushing, spraying, etc.) without additional cross-linking. The underline mechanism is attributed to the re-establishment of intermolecular hydrogen bond mediated cross-linking between PVA and TA during ethanol evaporation. Consequently, the resultant hydrogel coating exhibits ultra-high strength (>10 MPa), swelling volume stability, and excellent oil-water separation efficiency (>99%). This study will provide new insights into the scalable fabrication of hydrogel-coated porous materials for oil/water separation in industrial scenarios. 相似文献
5.
Rosangela Mastrangelo Damiano Bandelli Luciano Pensabene Buemi Piero Baglioni 《Advanced functional materials》2024,34(41):2404287
Soft matrices with tuned properties are part of the vast landscape of innovative materials for the restoration of works of art. “Twin chain” polymer networks (TC-PNs) based on polyvinyl alcohol have proven unique as scaffolds for Cultural Heritage cleaning. They enable optimum adaptability, adhesion, porosity, and connectivity at both micro- and nano-scale resulting in superior time/space-controlled cleaning operations. In this work, TC-PNs properties are tuned through a mild crosslinking of the poly(vinyl alcohol) (PVA)-porogen polymer by using sebacic, adipic, or succinic acid. The modified porogens have different structural features imparting a different phase behavior to TC-PVAs mixtures in aqueous solution, i.e., in pre-gel systems used to form gels through a liquid–liquid phase separation. The macro-, micro-, and nanoscale features of the final gels are characterized by Confocal Laser Scanning Microscopy, Small Angle X-ray Scattering, Rheology and are related to their cleaning performances. The study shows that the gels cleaning capacity is related to their tortuosity, that can be tailored at the nanoscale. Counterintuitively gels with higher tortuosity show better performances as evidenced by the cleaning of mockups and paintings from Jean Helion, Jackson Pollock, and Tancredi Parmeggiani at Peggy Guggenheim Collection in Venice. 相似文献
6.
7.
In this work, on‐demand control of liquids is realized by using elastic, patterned omniphobic surfaces. This paves the way for novel microfluidics, as well as liquid harvesting, transportation, and manipulation technologies. Inspired by the lubricating properties of pitcher plants, microstructured 1,2‐polybutadiene honeycomb and pincushion films obtained by self‐organization are fluorinated by the ene‐thiol reaction and infused with fluorinated lubricant to obtain omniphobic liquid‐repellent surfaces. Unlike conventional bioinspired omniphobic surfaces, the liquid repellency of the fabricated surface can be programmed by changing the surface microstructures via patterning of the film. Furthermore, the elasticity of the omniphobic film is suitable for controlling the repellency through external stimuli. The method presented here for the fabrication of lubricant‐infused omniphobic microstructured surfaces is also simple, cost‐effective, and can be scaled for large area fabrication. 相似文献
8.
Simon J. Dünki Yee Song Ko Frank A. Nüesch Dorina M. Opris 《Advanced functional materials》2015,25(16):2467-2475
A one‐step process for the synthesis of elastomers with high permittivity, excellent mechanical properties and increased electromechanical sensitivity is presented. It starts from a high molecular weight polymethylvinylsiloxane, P1 , whose vinyl groups serve two functions: the introduction of polar nitrile moieties by reacting P1 with 3‐mercaptopropionitrile ( 1 ) and the introduction of cross‐links to fine tune mechanical properties by reacting P1 with 2,2′‐(ethylenedioxy)diethanethiol ( 2 ). This twofold chemical modification furnished a material, C2 , with a powerful combination of properties: permittivity of up to 10.1 at 104 Hz, elastic modulus Y10% = 154 kPa, and strain at break of 260%. Actuators made of C2 show lateral actuation strains of 20.5% at an electric field as low as 10.8 V μm–1. Additionally, such actuators can self‐repair after a breakdown, which is essential for an improved device lifetime and an attractive reliability. The actuators can be operated repeatedly and reversibly at voltages below the first breakdown. Due to the low actuation voltage and the large actuation strain applications of this material in commercial products might become reality. 相似文献
9.
Feichen Yang Jiacheng Zhao William J. Koshut John Watt Jonathan C. Riboh Ken Gall Benjamin J. Wiley 《Advanced functional materials》2020,30(36)
This article reports the first hydrogel with the strength and modulus of cartilage in both tension and compression, and the first to exhibit cartilage‐equivalent tensile fatigue strength at 100 000 cycles. These properties are achieved by infiltrating a bacterial cellulose (BC) nanofiber network with a poly(vinyl alcohol) (PVA)–poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid sodium salt) (PAMPS) double network hydrogel. The BC provides tensile strength in a manner analogous to collagen in cartilage, while the PAMPS provides a fixed negative charge and osmotic restoring force similar to the role of aggrecan in cartilage. The hydrogel has the same aggregate modulus and permeability as cartilage, resulting in the same time‐dependent deformation under confined compression. The hydrogel is not cytotoxic, has a coefficient of friction 45% lower than cartilage, and is 4.4 times more wear‐resistant than a PVA hydrogel. The properties of this hydrogel make it an excellent candidate material for replacement of damaged cartilage. 相似文献
10.
We developed a new photonic crystal hydrogel material based on the biocompatible polymer poly (vinyl alcohol) (PVA), which can be reversibly dehydrated and rehydrated, without the use of additional fillers, while retaining the diffraction and swelling properties of polymerized crystalline colloidal arrays (PCCA). This chemically modified PVA hydrogel photonic crystal efficiently diffracts light from the embedded crystalline colloidal array. This diffraction optically reports on volume changes occurring in the hydrogel by shifts in the wavelength of the diffracted light. We fabricated a pH sensor, which demonstrates a 350 nm wavelength shift between pH values of 3.3 and 8.5. We have also fabricated a Pb+2 sensor, in which pendant crown ether groups bind lead ions. Immobilization of the ions within the hydrogel increases the osmotic pressure due to the formation of a Donnan potential, swelling the hydrogel and shifting the observed diffraction in proportion to the concentration of bound ions. The sensing responses of rehydrated PVA pH and Pb+2 sensors were similar to that before drying. This reversibility of rehydration enables storage of these hydrogel photonic crystal sensors in the dry state, which makes them much more useful for commercial applications. 相似文献
11.
Matthew L. Smith Connor Slone Kevin Heitfeld Richard A. Vaia 《Advanced functional materials》2013,23(22):2835-2842
Critical technologies from medicine to defense are highly dependent on advanced composite materials. Increasingly there is a greater demand for materials with expanded functionality. The state of the art includes a wide range of responsive composites capable of impressive structural feats such as externally triggered shape morphing. Here a different composite concept is presented, one in which a portion of the constituent materials feed off of ambient energy and dynamically couple to convert it to mechanical motion in a cooperative, biomimetic fashion. Using a recently developed self‐oscillating gel based on gelatin and the oscillating Belousov–Zhabotinsky (BZ) reaction, a technique is demonstrated for producing continuous patterned heterogeneous BZ hydrogel composites capable of sustained autonomic function. The coupling between two adjacent reactive patches is demonstrated in an autonomic cantilever actuator which converts chemical energy into amplified mechanical motion. The design of heterogeneous BZ gels for motion using a basic finite element model is discussed. This work represents notable progress toward developing internally responsive, bio‐inspired composite materials for constructing modular autonomic morphing structures and devices. 相似文献
12.
Ke Wu Yanyu Cui Yaping Song Zhiyan Ma Juan Wang Juan Li Teng Fei Tong Zhang 《Advanced functional materials》2023,33(24):2300239
Hydrogels are promising materials for electronic skin due to their flexibility and modifiability. Reported hydrogel electronic skins can recognize stimulations and output signals, but the single output signal and the requirement of external power source limit their further applications. In this study, inspired by the neuron system, the self-powered neuron system-like hydrogels based on gelatin, water/glycerin and ionic liquid modified metal organic frameworks (MOFs) are prepared. The optimized hydrogel exhibits excellent adhesion (40 kPa), stretchability (0%–100%), water retention (>92% at 0% relative humidity (RH) atmosphere), ionic conductivity (>10−3 S m−1) and stability (>30 days). Besides, the neuron system-like hydrogels are highly sensitive to pressure (0—10 N) and humidity (0%–75% RH) with dual-modal output, without external power source. Finally, the optimized hydrogel ionic skin is applied in human motion detection, energy harvesting, and low humidity sensing. This study provides a preliminary exploration of self-powered ionic skin for multi-application scenarios. 相似文献
13.
Matthew L. Smith Connor Slone Kevin Heitfeld Richard A. Vaia 《Advanced functional materials》2013,23(22):2786-2786
14.
The functionalization of a hydrogel with target molecules is one of the key steps in its various applications. Here, a versatile approach is demonstrated to functionalize a micropatterned hydrogel, which is formed by “thiol‐yne” photo‐click reaction between the yne‐ended hyperbranched poly(ether amine) (hPEA‐yne) and thiol‐containing polyhedral oligomeric silsesquioxane (PEG‐POSS‐SH). By controlling the molar ratio between hPEA‐yne and PEG‐POSS‐SH, patterned hydrogels containing thiol or yne groups are obtained. A series of thiol‐based click chemistry such as “thiol‐epoxy”, “thiol‐halogen”, “thiol‐ene”, and “thiol‐isocyanate” are used to functionalize the thiol‐containing hydrogel (Gel‐1), while the yne‐containing hydrogel (Gel‐2) is functionalized through a typical copper‐catalysed alkyne‐azide reaction (CuAAC). FTIR, UV‐vis spectra and confocal laser scanning microscopy (CLSM) are used to trace these click reactions. Due to the selective adsorption to the hydrophilic dyes, the obtained patterned hydrogel of hPEA modified with fluorescence dye is further demonstrated in application for the recognition of guest molecules. 相似文献
15.
16.
Nannan Wang Yange Feng Youbin Zheng Liqiang Zhang Min Feng Xiaojuan Li Feng Zhou Daoai Wang 《Advanced functional materials》2021,31(14):2009172
The water vapor exhaled by the human body can severely accelerate the charge dissipation of a polypropylene (PP)-based medical mask, thereby reducing the electrostatic adsorption efficiency to cause infection. To solve this problem, a new type of polyvinyl alcohol (PVA)-based medical mask through electrostatic spinning to replace the PP melt-blown layer, which has self-charging and charge retention performance in a high humidity environment is fabricated. The PVA is rich in hydroxyl groups, which can spontaneously form hydrogen bonds with water vapor molecules exhaled by the human body and fix water molecules to increase the triboelectricity. By analyzing the electrical output performance of PVA-based triboelectric nanogenerator (TENG), it is shown that the short circuit current is ≈26 times larger than that of PP-based TENG in 95% relative humidity (RH). Moreover, PVA has a strong charge storage capacity and self-charging performance, as determined by hand touching under a high humidity environment. The static dissipation rate of PVA is 1.4 times lower than that of PP at a 95% RH. In comparison with PP-based medical masks, PVA-based medical masks have a high humidity resistance and self-charging performance and can be easily recharged in situ by hand slapping without taking it off for many times. 相似文献
17.
Pietro Cataldi Pietro Steiner Mufeng Liu Gergo Pinter Athanassia Athanassiou Coskun Kocabas Ian A. Kinloch Mark A. Bissett 《Advanced functional materials》2023,33(30):2301542
A green textile-based conductor with controllable electrical resistance change with deformation and transiency (i.e., dissolution in water) will be the holy grail in wearable electronics since it can satisfy divergent needs with a single solution and be sustainable simultaneously. Nevertheless, designing such material is challenging since opposite requirements shall be satisfied. To solve such a problem, cotton is functionalized using conductive inks made of graphene or carbon nanofiber, a biodegradable polyvinyl alcohol binder, and environmentally friendly solvents. The electrical resistance shows an anisotropic response to bending depending on the composition of the coating and the stress direction, functioning either as a deformable compliant electrode or a tunable piezoresistor. Indeed, it can withstand thousands of bending cycles with a change in resistance of less than 5% or change its resistance by many orders of magnitude with the same deformation thanks to the combination of cotton twill and different nanofillers. A simple modification in the binder composition adding waterborne polyurethane allows the coating to go from entirely transient in water within minutes to withstanding simulated washing cycles for hours without losing its electrical conductivity. This green versatile conductor may serve opposing needs by altering the material composition and the deformation direction. 相似文献
18.
采用聚乙烯醇作粘结剂,制备了纳米晶Fe73.5Cu1Nb3Si13.5B9磁粉芯.并对该类磁粉芯的磁性能进行了测试分析.结果表明,随粉体粒度减小,磁粉芯的μr减小、Bm、Hc上升;随压力增大,粉芯的致密度、μr、Bm上升,Hc值下降;磁粉芯的中心频率为10 MHz,其最大Q值为99.6.这种材料在高频范围内具有应用价值. 相似文献
19.
采用聚乙烯醇作粘结剂，制备了纳米晶Fe73．5CulNb3Si13.5B9磁粉芯。并对该类磁粉芯的磁性能进行了测试分析。结果表明，随粉体粒度减小，磁粉芯的μr减小、Bm、Hc上升；随压力增大，粉芯的致密度、μr，Bm上升，Hc值下降；磁粉芯的中心频率为10MHz，其最大Q值为99．6。这种材料在高频范围内具有应用价值。 相似文献
20.
基于Mach-Zehnder干涉的湿度光纤传感器的研究 总被引：1，自引：0，他引：1
介绍了一种可测量相对湿度的March-Zehnder(MZ)干涉的湿度光纤传感器,其传感结构是在两段标准单模之间腰椎放大熔接一段长为15 mm的单模光纤,并在中间的单模部分涂上一层5%的聚乙烯醇(PVA)。PVA的折射率随着环境湿度的变化而改变,从而使包层模有效折射率发生变化。当中间单模光纤周围环境湿度发生变化时,相应干涉峰中心波长也会发生移动,通过测量透射光谱来测量包层周围环境的湿度变化。实验测得该湿度传感器的灵敏度为0.0983 nm/%RH(RH表示相对湿度)。实验也证明基于MZ干涉的湿度光纤传感器具有良好的稳定性等一系列突出的优点。 相似文献