ACS Nano
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2024
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IF 15.8
Di Wang,Shouhua Feng,Ming Yang
The heterogeneity of bones is elegantly adapted to the local strain environment, which is critical for maintaining mechanical functions. Such an adaptation enables the strong correlation between strain distributions and multiple gradients, underlying a promising pathway for creating complex gradient structures. However, this potential remains largely unexplored for the synthesis of functional gradient materials. In this work, heterogeneous bone-like nanocomposites with complex structural and compositional gradients comparable to bones are synthesized by inducing strain distributions within the polymer matrix containing amorphous calcium phosphate (ACP). Uniaxial stretching of composite films exerts the highest strain in the center, which ceases gradually toward the sides, resulting in the gradual decrease of polymer alignment and crystallinity. Simultaneously, the center with high orientation traps most ACP during stretching due to the nanoconfinement effect, which in turn promotes the formation of aligned nanofibrous structures. The sides experiencing the least strain have the smallest amounts of ACP, characteristic of porous architectures. Further crystallization of ACP produces oriented apatite nanorods in the center with a larger crystalline/amorphous ratio than the sides because of template-induced crystallization. The combination of structural and compositional gradients leads to gradient mechanical properties, and the gradient span and magnitude correlate nicely with strain distributions. Accompanying bone-like mechanical gradients, the center is less adhesive and self-healable than the sides, which allows a better recovery after a complete cutting. Our work may represent a general strategy for the synthesis of biomimetic materials with complex gradients thanks to the ubiquitous presence of strain distributions in load-bearing structures.
研究领域:
材料科学
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生物医学工程
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纳米技术
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产品关联
DOI
PubMed
高影响因子
Joule
·
2024
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IF 38.6
Qiu Xiong,Xiaofeng Huang,Can Wang,Qin Zhou,Yong Gang,Tinghao Li,Chongzhu Hu,Ni Zhang,Xiaobing Wang,Jihuai Wu,Zhenhuang Su,Xingyu Gao,Xin Li,Nanfeng Zheng,Peng Gao
Although X-ray diffraction (XRD) technology has played an essential role in studying the lattice strain of perovskite solar cells (PSCs), accurate construction of the relationship between strains and PSC performance remains challenging due to its limitations. This study investigates the spatial strain distributions of perovskite films on electron transport layers (ETLs) with different surface free energies (γ s s) through confocal micro-Raman spectroscopy (CMRS) mapping and XRD technology. Results showed that CMRS mapping could more effectively reflect the distribution and size of spatial strain. Uniformed spatial strain with larger grain and preferred orientations can be realized over substrates with optimized γ s , corresponding to recombination suppression and interfacial carrier extraction enhancement and significantly reducing open-circuit voltage ( V OC ) deficits. Optimized PSCs achieve the power conversion efficiency (PCE) of 24.64% and demonstrate excellent compatibility toward large-area or flexible applications, with 20.66% and 22.13% PCEs based on perovskite mini-module and flexible PSCs, respectively.
研究领域:
材料科学
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光伏技术
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光学工程
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产品关联
DOI
高影响因子
Journal of Physical Chemistry C
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2021
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IF 4.126
Xiaoming Ma,Fang Lin,Xin Chen,Chuanhong Jin
Oxidative etching possesses an enriched flexibility and atomic-level accuracy in tailoring the size, morphology, surface structure, and composition of colloidal nanocrystals toward their catalytic and sensing applications. In this work, we choose one-dimensional penta-twinned Pd nanorods as a model system and apply liquid cell transmission electron microscopy (LCTEM) to investigate the detailed nanoscale etching process under different solution environments, which are DI water/e-beam (weakly oxidative), sodium chloride (NaCl) solution/e-beam (moderately oxidative), and ferric chloride (FeCl3) solution/e-beam (strongly oxidative), respectively. Increasing the oxidative strength of solution alone accelerates the dissolution kinetics and drives the system from the (near)-equilibrium etching, where nanorods appear in flat and low-indexed ends (for DI water/e-beam) to nonequilibrium etching with slender tips formed as intermediate products (for FeCl3/e-beam). Under a nonequilibrium etching condition, both symmetric and asymmetric etching occurred, that is, the penta-twinned structure either retained (for symmetric etching) or dissolved to a fourfold-, threefold-, and twofold-twinned and single-crystalline structure (for asymmetric etching), depending on the structural defects-induced strain distribution. The formation of slender tips of different structures can be further understood via energetic analysis and strain relaxation. In particular, in situ LCTEM results were successfully reproduced by flask system-based etching experiments; hence, direct correlations were built between LCTEM and conventional colloidal etching reactions. This work comprehends the present understanding on the synergetic roles of structure characteristics and solution chemistry for the etching of multiply twinned nanoparticles toward their precise controlled synthesis and practical applications.
研究领域:
材料科学
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纳米技术
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催化
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化学工程
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表面科学
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
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IF 4.9
Haofei Sima,Bo Liu,Xiaolin Shi,Zifei Zhao,Chaozong Liu,Chunling Zhang
In light of the exponential growth of flexible human-computer interactions and telecommunications, it is becoming increasingly important to develop a high-sensitivity strain sensor to monitor human movement. Herein, the biocompatible, adhesive, and flexible Tannic acid-Fe 3 O 4 @MXene-poly(methacryloxyethyl sulfobetaine/acrylamide) (TFM) hydrogel has been prepared to realize the dual-functional applications in strain sensitive sensor and electromagnetic interference (EMI) shielding. The polymer network and 2D conductive filler MXene together construct the conductive network inside the hydrogel. The interpenetrating network and hydrogen bond between poly(acrylamide) and poly(methacryloxyethyl sulfobetaine) chain enhance the mechanical property of hydrogel, which is also improved by the complexation between Fe 3 O 4 and the catechol groups of tannic acid. Benefiting from the excellent electrical conductivity (∼1.33 S/m) and mechanical property of the TFM hydrogels, the strain sensor displays compressive strain (∼77.6 %) and elongation (∼308.5 %), adhesion (∼16 kPa), compression sensitivity (∼42.6 Pa −1 ), gauge factor (GF = 2.38), and cyclic stability (∼50 cycles). TFM hydrogels can monitor strain distribution sensing, pulse beating and human movement detection. Moreover, the TFM hydrogel exhibits an absorption-predominant EMI shielding performance with an effective value of ∼25.2 dB. This work provides a new inspiration for the development of multifunctional hydrogels in the fields of artificial intelligence, human-computer interaction, and EMI shielding technology.
研究领域:
材料科学
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电子学
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生物医学工程
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人机交互
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人工智能
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电磁干扰屏蔽
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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）