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1.
Jiaqing He Qiang Zhou Zhiqing Ge Shunfeng Jiang Jiahe Li Wei Feng Haiyang Yang 《Advanced functional materials》2024,34(42):2404341
Temperature-responsive hydrogels including lower critical solution temperature (LCST)- and upper critical solution temperature (UCST)-type hydrogels are attractive in various fields. However, the swift switch between LCST and UCST stimuli-responsive behaviors remains intriguing and challenging. Here is reported a kind of hydrogel with pH-gated LCST and UCST response behaviors. This is achieved using the hydrogen bonding between carboxylic acid groups of poly(acrylic acid-co-acrylamide) and hydroxyl groups of hydroxypropyl cellulose (HPC). The poly(acrylic acid-co-acrylamide)-HPC (PACA-HPC) hydrogels exhibit pH-gated reversible LCST-UCST phase transition behavior. When the transparent PACA-HPC hydrogel is placed in an acid bath, the COO− groups get protonated, rapidly forming hydrogen bonds with HPC to render a light-scattering state making the hydrogel opaque. Furthermore, the opaque hydrogel exhibits UCST phase transition behavior at 20–45 °C. When the opaque PCAC-HPC hydrogel is placed in an alkaline environment, hydrogen-bonded complexes gradually dissociate as the COOH groups are deprotonated to form a homogeneous transparent state. The transparent hydrogel exhibits LCST phase transition behavior at 20–45° C. Therefore, is shown the hydrogen bonding strategy to fabricate hydrogels with tunable LCST and UCST responses. With this pH-gated hydrogel with switchable LCST/UCST responsive behaviors, are demonstrated its applications in smart windows and information encryption. 相似文献
2.
Jianhua Zhang Jiahe Liao Zemin Liu Rongjing Zhang Metin Sitti 《Advanced functional materials》2024,34(31):2308238
Recent advances in composite hydrogels achieve material enhancement or specialized stimuli-responsive functionalities by pairing with a functional filler. Liquid metals (LM) offer a unique combination of chemical, electrical, and mechanical properties that show great potential in hydrogel composites. Polymerization of hydrogels with LM microdroplets as initiators is a particularly interesting phenomenon that remains in its early stage of development. In this work, an LM-hydrogel composite is introduced, in which LM microdroplets dispersed inside the hydrogel matrix have dual functions as a polymerization initiator for a polyacrylic acid-poly vinyl alcohol (PAA/PVA) network and, once polymerized, as passive inclusion to influence its material and stimuli-responsive characteristics. It is demonstrated that LM microdroplets enable ultra-fast polymerization in ≈1 min, compared to several hours by conventional polymerization techniques. The results show several mechanical enhancements to the PAA/PVA hydrogels with LM-initiated polymerization. It is found that LM ratios strongly influence stimuli-responsive behaviors in the hydrogels, including swelling and ionic bending, where higher LM ratios are found to enhance ionic actuation performance. The dual roles of LM in this composite are analyzed using the experimental characterization results. These LM-hydrogel composites, which are biocompatible, open up new opportunities in future soft robotics and biomedical applications. 相似文献
3.
Qian Yan Renjie Ding Haowen Zheng Pengyang Li Zonglin Liu Zhong Chen Jinhua Xiong Fuhua Xue Xu Zhao Qingyu Peng Xiaodong He 《Advanced functional materials》2023,33(34):2301982
Near-infrared (NIR) light-responsive hydrogels have the advantages of high precision, remote control and excellent biocompatibility, which are widely used in soft biomimetic actuators. The process by which water molecules diffuse can directly affect the deformation of hydrogel. Therefore, it remains a serious challenge to improve the response speed of hydrogel actuator. Herein, an anisotropic photo-responsive conductive hydrogel is designed by a directional freezing method. Due to the anisotropy of the MXene-based PNIPAM/MXene directional (PMD) hydrogel, its mechanical properties and conductivity are enhanced in a specific direction. At the same time, with the presence of the internal directional channels and the assistance of capillary force, the PMD hydrogel can achieve a volume deswelling of 70% in 2 s under light irradiation, further building a hydrogel actuator with a fast response performance. Additionally, the hydrogel actuator can lift an object 40 times its weight by a distance of 6 mm, realizing the advantages of both rapid responsiveness and high driving strength, which makes the hydrogel actuator have important application significance in remote control, microflow valve, and soft robot. 相似文献
4.
Johan Karlsson Stephany Y. Tzeng Shayan Hemmati Kathryn M. Luly Olivia Choi Yuan Rui David R. Wilson Kristen L. Kozielski Alfredo Quiñones-Hinojosa Jordan J. Green 《Advanced functional materials》2021,31(17):2009768
Clinical translation of polymer-based nanocarriers for systemic delivery of RNA has been limited due to poor colloidal stability in the blood stream and intracellular delivery of the RNA to the cytosol. To address these limitations, this study reports a new strategy incorporating photocrosslinking of bioreducible nanoparticles for improved stability extracellularly and rapid release of RNA intracellularly. In this design, the polymeric nanocarriers contain ester bonds for hydrolytic degradation and disulfide bonds for environmentally triggered small interfering RNA (siRNA) release in the cytosol. These photocrosslinked bioreducible nanoparticles (XbNPs) have a shielded surface charge, reduced adsorption of serum proteins, and enable superior siRNA-mediated knockdown in both glioma and melanoma cells in high-serum conditions compared to non-crosslinked formulations. Mechanistically, XbNPs promote cellular uptake and the presence of secondary and tertiary amines enables efficient endosomal escape. Following systemic administration, XbNPs facilitate targeting of cancer cells and tissue-mediated siRNA delivery beyond the liver, unlike conventional nanoparticle-based delivery. These attributes of XbNPs facilitate robust siRNA-mediated knockdown in vivo in melanoma tumors colonized in the lungs following systemic administration. Thus, biodegradable polymeric nanoparticles, via photocrosslinking, demonstrate extended colloidal stability and efficient delivery of RNA therapeutics under physiological conditions, and thereby potentially advance systemic delivery technologies for nucleic acid-based therapeutics. 相似文献
5.
Michael T. Cook Peter Haddow Stewart B. Kirton William J. McAuley 《Advanced functional materials》2021,31(8):2008123
The ability to trigger changes to material properties with external stimuli, so-called “smart” behavior, has enabled novel technologies for a wide range of healthcare applications. Response to small changes in temperature is particularly attractive, where material transformations may be triggered by contact with the human body. Thermoreversible gelators are materials where warming triggers reversible phase change from low viscosity polymer solution to a gel state. These systems can be generated by the exploitation of macromolecules with lower critical solution temperatures included in their architectures. The resultant materials are attractive for topical and mucosal drug delivery, as well as for injectables. In addition, the materials are attractive for tissue engineering and 3D printing. The fundamental science underpinning these systems is described, along with progress in each class of material and their applications. Significant opportunities exist in the fundamental understanding of how polymer chemistry and nanoscience describe the performance of these systems and guide the rational design of novel systems. Furthermore, barriers to translating technologies must be addressed, for example, rigorous toxicological evaluation is rarely conducted. As such, applications remain tied to narrow fields, and advancements will be made where the existing knowledge in these areas may be applied to novel problems of science. 相似文献
6.
Tiwa Yimyai Raweewan Thiramanas Treethip Phakkeeree Supitchaya Iamsaard Daniel Crespy 《Advanced functional materials》2021,31(37):2102568
Biofouling on surfaces immersed in aquatic environment induces catastrophic corrosion of metallic materials in petrochemical infrastructures, maritime facilities, and power plants. To combat the synergistic effect of biofouling and corrosion on the deterioration of metallic materials, smart coatings possessing a dual function of antibiofouling and anticorrosion properties are needed. Herein, redox-responsive copolymer conjugates are synthesized and employed as coatings with the dual function of biofouling and corrosion mitigation. The dual function of copolymers is attributed to fluorinated units and the corrosion inhibitor 2-mercaptobenzothiazole (MBT) conjugated via disulfide linkages. Indeed, the disulfide linkages can be cleaved in a reducing environment, yielding controlled release of the corrosion inhibitor MBT during corrosion process. The antibiofouling action against protein adsorption and algal attachment is enabled by cooperation of the repellent characteristic of fluorinated moieties and the biocidal effect of conjugated MBT. 相似文献
7.
Prathamesh D. Raiter Yuval Vidavsky Meredith N. Silberstein 《Advanced functional materials》2021,31(4):2006969
Multifunctionality in polymers facilitates their application in emerging technologies. Electrical fields are a preferred stimulus because of the speed and ease of application to bulk polymers. While a wide range of electrically triggered actuators are developed, and electrically controlled adhesion between gels is demonstrated, modification of bulk mechanical properties via electrical stimuli remains elusive. Polymers with covalently incorporated ionic charge (polyelectrolytes) should be well suited to achieving this goal since the mechanical properties depend on electrostatic interactions and these charges are intrinsically susceptible to electric fields. Molecular dynamics simulations are utilized here to investigate whether electric fields can modulate the mechanical properties of polyelectrolytes and to understand the governing mechanisms. Mechanical property modulation by electric field is found to be sensitive to the charge distribution—charges must be tightly attached to the polymer backbone, and responsivity is greater if a single backbone contains both positive and negative charges. The dominant mechanisms are reorientation and stretching of the polymer chains, which also elongate the ionic clusters to maintain strong electrostatic interactions throughout deformation. These insights are critical for future experimental realization of polymers with electric field regulated mechanical properties. 相似文献
8.
Bar Israeli Daniela S. Strugach Sigal Gelkop Shir Weber Dor S. Gozlan Miriam Amiram 《Advanced functional materials》2021,31(44):2011276
A general and versatile technology to engineer light-responsive protein-based biomaterials can enable the manipulation and interrogation of proteins, pathways, and cells, and it will assist the design of “smart” light-responsive biomaterials. This study reports the evolution of chromosomal aminoacyl-tRNA synthetases (aaRSs) for azobenzene-bearing unnatural amino acids (uAAs) with up to ≈40-fold increased protein production and improved fidelity, as compared with a previously described aaRS. The evolved translation systems enable efficient and accurate incorporation of up to 10 instances of the various light-responsive uAAs in elastin-like polypeptides (ELPs). Azobenzene-containing ELPs are capable of isothermal, reversible, light-mediated soluble-to-insoluble phase transition, with up to a 12 °C difference in the ELP transition temperature upon cis-to-trans azobenzene isomerization. Furthermore, the incorporation of azobenzene-uAAs in ELP diblock-copolymers enables the creation of light-responsive self-assembled nanostructures. Finally, light-responsive resilin-inspired polymers are also generated by multi-site azobenzene-incorporation. The translation machinery evolved in this study can be used for the multi-site incorporation of azobenzene moieties at the polypeptide level and constitute a universal methodology for the design of light-responsive proteins and additional families of protein-based biomaterials with customized and tunable light-responsive behavior. 相似文献
9.
We report a new method for generating both continuous and discrete density gradients in microparticles of biodegradable polymers via an electrospray technique. The gradients were generated by spatially varying the deposition time of electrosprayed microparticles. The substrate coated with a density gradient of microparticles has varying surface roughness, offering a unique system for studying the effect of physical cues on neurite outgrowth from dorsal root ganglia. We obtained an optimal surface roughness for promoting neuron adhesion and neurite extension in vitro. Furthermore, this capability of approach was extended to generate a gradient of fluorescein isothiocyanate-labeled bovine serum albumin by encapsulating it in the polymer microparticles in situ during electrospray. Taken together, this new class of substrates with gradients of microparticle density can potentially be used in various biomedical applications such as neural tissue engineering. 相似文献
10.
Jing Zhang Yunfeng Zeng Yongyuan Heng Yu Shen Ximeng Sun Yijia Wang Haiping Zheng Ming Zeng Ziyi Yu 《Advanced functional materials》2024,34(30):2400858
Advancing the integration of nonliving and living components relies heavily on functional hydrogel materials with biocompatibility and customizability. In this study, an enzyme-assisted surface activation method is developed to produce reactive hydrogel microparticles (HMPs) comprising thiolated hyaluronic acid and hyperbranched poly(β-hydrazide esters). Fluorescence labeling analysis reveals an over six-fold increase in surface-active functional group density on the hydrogels and three-fold on HMPs after enzyme activation. This enhancement improves accessibility of active elements, facilitating post-functionalization and optimizing their capacity to support initial cell adhesion and spreading as carriers for cell cultures. Additionally, by utilizing the exposed reactive double bonds on the HMP surfaces post-enzymatic treatment, thiolated HMPs are produced through a thiol-ene coupling reaction with thiolated polymers. These thiolated HMPs bond together spontaneously, resulting in the formation of annealed granular hydrogels with interconnected large-pore networks and a tunable storage modulus (G’) from tens to hundreds of pascals, compatible with most soft tissues. Integrated with 3D bioprinting, this hydrogel ink generates prints that foster cell adhesion, migration, growth, and network formation. Moving forward, integrating various granular hydrogel scaffold systems with the enzyme-assisted activation technique holds significant promise for enhancing performance and expanding applications in regenerative medicine and innovative living materials. 相似文献
11.
通过模拟计算设计出一种透射比为99%、包含一层TiO2薄膜和一层SiO2薄膜的宽带高增透膜。两层薄膜均由溶胶-凝胶法制得并采用提拉法成形于玻璃基片上。对增透膜样品的透射比、表面形貌、膜厚等进行了表征,考察了提拉速度、退火温度、催化条件等对其透射比、表面均匀性的影响。结果表明:增透膜的使用提高了玻璃基片的透射比;当提拉速度为9cm/min,增透膜厚约为255nm时,基片在400～800nm波段的透射比提高了7%。控制退火温度,可以使增透膜在某些波段的透射比增强。增透膜样品的表面均匀性良好,室温下膜层的均方根表面粗糙度(RMS)为1.682,平均粗糙度(RA)为1.208,在550℃的温度以下,随着退火温度升高,表面粗糙度降低。 相似文献
12.
A scalable protocol for design and subsequent 3D-printing of polymeric core-shell-particles is reported. The particle synthesis by emulsion polymerization in starved-feed mode is used for tailoring particle architecture and composition. Control of size, mechanical properties, and chemical functionalities allow to achieve the specific requirement profile for subsequent extrusion-based additive manufacturing. The core-shell particles consist of hard polystyrene cores and a comparably soft polyalkylacrylate-based shell. Size and monodispersity, as well as core-to-shell ratio, are determined by means of dynamic light scattering and transmission electron microscopy. Thermal and rheological properties are investigated by means of dynamic scanning calorimetry and thermogravimetric analysis as well as oscillation and capillary rheometry. During 3D-printing, the monodisperse particles self-assemble into an ordered close packed lattice structure, leading to visible reflection colors according to Bragg's law of diffraction. Distinct and angle-dependent reflection colors are recorded via UV-vis spectroscopy. As the structural color depends, inter alia, on the underlying particle sizes, resulting colors are easily tunable by adjusting the applied synthesis parameters. Under mechanical deformation, the color changes due to controlled lattice deformation, which enables mechanochromic sensing with the printed objects. They are also promising candidates for decorative ornaments, smart optical coatings, or advanced security devices. 相似文献
13.
为了进一步揭示激光的热力效应对电化学沉积的强化作用,构建了激光电化学复合沉积试验系统,进行了理论分析和实验验证。采用激光循环往复的扫描方式照射沉积区域制备沉积层试样,对沉积过程中的力效应和热效应进行测试,最后采用扫描电子显微镜对沉积层的表面形貌和截面形貌进行观察对比。结果表明,激光的热力效应能加快金属离子的还原反应,促进晶核形成和晶粒细化,在激光能量为0.2mJ（20kHz）时,能获得良好的沉积速率（0.198mg/min）;在激光能量为0.4mJ（20kHz）时,沉积层的拉伸强度性能较好,达到256.38 MPa。此研究结果对电解加工技术的发展是有一定帮助的。 相似文献
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15.
Hua Zhang Yang Cong Amarachi Rosemary Osi Yang Zhou Fangcheng Huang Remo P. Zaccaria Jing Chen Rong Wang Jun Fu 《Advanced functional materials》2020,30(13)
Biocompatible hydrogel inks with shear‐thinning, appropriate yield strength, and fast self‐healing are desired for 3D bioprinting. However, the lack of ideal 3D bioprinting inks with outstanding printability and high structural fidelity, as well as cell‐compatibility, has hindered the progress of extrusion‐based 3D bioprinting for tissue engineering. In this study, novel self‐healable pre‐cross‐linked hydrogel microparticles (pcHμPs) of chitosan methacrylate (CHMA) and polyvinyl alcohol (PVA) hybrid hydrogels are developed and used as bioinks for extrusion‐based 3D printing of scaffolds with high fidelity and biocompatibility. The pcHμPs display excellent shear thinning when injected through a syringe and subsequently self‐heal into gels as shear forces are removed. Numerical simulations indicate that the pcHμPs experience a plug flow in the nozzle with minimal disturbance, which favors a steady and continuous printing. Moreover, the pcHμPs show a self‐supportive yield strength (540 Pa), which is critical for the fidelity of printed constructs. A series of biomimetic constructs with very high aspect ratio and delicate fine structures are directly printed by using the pcHμP ink. The 3D printed scaffolds support the growth of bone‐marrow‐derived mesenchymal stem cells and formation of cell spheroids, which are most important for tissue engineering. 相似文献
16.
高Al组分AlGaN材料优化生长与组分研究 总被引：2，自引：2，他引：0
研究了金属有机化合物化学气相沉积(MOCVD)系统外延高Al组分较厚AlGaN薄膜材料的生长技术。实验发现,AlGaN/GaN结构中的AlGaN材料的相分离现象可能是由于过低的生长V/III以及材料所受的张应力状态所致,而V/III过高时则会出现Al源的并入效率饱和。采用AlN过渡层技术,外延生长了表面无裂纹的45%Al组分较厚(100～200nm)AlGaN薄膜材料。所得材料的Al组分与气相Al组分相同,(0002)面X射线衍射(XRD)双晶摇摆曲线半高宽(FWHM)为376arcsec,并发现AlN过渡层的质量影响着其上AlGaN材料的Al组分与晶体质量。实验观察到AlGaN材料的表面形貌随着样品中Al组分的增加从微坑主导模式逐步转变为微裂主导模式,采用AlN过渡层可延缓这一转变。 相似文献
17.
A general and versatile route to prepare hierarchical polymer microparticles via interfacial instabilities of emulsion droplets is demonstrated. Uniform emulsion droplets containing hydrophobic polymers and n‐hexadecanol (HD) are generated through microfluidic devices. When organic solvent diffuses through the aqueous phase and evaporates, shrinking emulsion droplets containing HD and polystyrene (PS) will trigger interfacial instabilities to form microparticles with wrinkled surfaces. Interestingly, surface‐textures of the particles can be accurately tailored from smooth to high textures by varying the HD concentration and/or the rate of solvent evaporation. Moreover, composite particles can be generated by suspending different hydrophobic species to the initial polymer solutions. This versatile approach for preparing particles with highly textured surfaces can be extended to other type of hydrophobic polymers which will find potential applications in the fields of drug delivery, tissue engineering, catalysis, coating, and device fabrication. 相似文献
18.
Yang Gao Jiaojiao Chen Xiuyuan Han Yudong Pan Peiyao Wang Tiejun Wang Tongqing Lu 《Advanced functional materials》2020,30(36)
Achieving adhesion between hydrogels and diverse materials in a facile and universal way is challenging. Existing methods rely on special chemical or physical properties of the hydrogel and adherends, which lead to limited applicability and complicated pretreatments. A stitch‐bonding strategy is proposed here by introducing a polymer chain with versatile functional group and triggerable crosslinking property inspired by catechol chemistry. The polymer chain can stitch the hydrogel by forming a network in topological entanglement with the preexisting hydrogel network, and directly bond to the adherend surface by versatile chemical interactions. Through this, the polymer chain solution works as a universal glue for facile adhesion of hydrogels to diverse substrates like metals, glasses, elastomers, plastics, and living tissues, without requiring any chemical design or pretreatment for the hydrogel and adherends. The adhesion energy between polyacrylamide hydrogel and diverse substrates can reach 200–400 J m?2, and it can reach ≈900 J m?2 with a toughened polyacrylic acid polyacrylamide hydrogel. The mechanism of stitch‐bonding strategy is illustrated by studying various influence factors. 相似文献
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20.
Miao Qi Ruiqi Yang Zhe Wang Yanting Liu Qichong Zhang Bing He Kaiwei Li Qing Yang Lei Wei Caofeng Pan Mengxiao Chen 《Advanced functional materials》2023,33(17):2214479
Inspired by nature, various self-healing materials that can recover their physical properties after external damage have been developed. Recently, self-healing materials have been widely used in electronic devices for improving durability and protecting the devices from failure during operation. Moreover, self-healing materials can integrate many other intriguing properties of biological systems, such as stretchability, mechanical toughness, adhesion, and structural coloration, providing additional fascinating experiences. All of these inspirations have attracted extensive research on bioinspired self-healing soft electronics. This review presents a detailed discussion on bioinspired self-healing soft electronics. Firstly, two main healing mechanisms are introduced. Then, four categories of self-healing materials in soft electronics, including insulators, semiconductors, electronic conductors, and ionic conductors, are reviewed, and their functions, working principles, and applications are summarized. Finally, human-inspired self-healing materials and animal-inspired self-healing materials as well as their applications, such as organic field-effect transistors (OFETs), pressure sensors, strain sensors, chemical sensors, triboelectric nanogenerators (TENGs), and soft actuators, are introduced. This cutting-edge and promising field is believed to stimulate more excellent cross-discipline works in material science, flexible electronics, and novel sensors, accelerating the development of applications in human motion monitoring, environmental sensing, information transmission, etc. 相似文献