ADVANCES IN POLYMER TECHNOLOGY
·
2016
·Vol. 37
·期 3
·869-877
·
IF 1.114
Yongkang Bai,Yuejun Liu,Qihua Wang
In this work, a bio-shape memory polymer (SMP) with high performance is prepared by using cellulose acetate (CA) as raw material. The materials exhibit good mechanical properties with tensile strength and elongation at break over 46 MPa and 115%, respectively. With hydrogen bond interaction as physically cross-linked points, the materials also present excellent dual-shape memory properties with shape fixation and shape recovery ratio of about 99% and 96%, respectively. Moreover, the materials show good triple-shape memory effect. The recyclability of the materials is also investigated and the results show that the reclaimed samples still hold high mechanical and shape memory properties. With the intrinsic biocompatibility and biodegradation of CA, the materials could be an attractive candidate for applications in smart biomedical devices. Furthermore, the usage of CA as SMP could expand the view of preparing bio-SMP in future.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
Materials
·
2021
·Vol. 14
·期 12
·3193
·
IF 3.623
Tu Lan,Xiaolong Guo,De Li,Yong Chen
The memory effect of lithium-ion batteries (LIBs) was first discovered in LiFePO4, but its origin and dependence are still not clear, which is essential for regulating the memory effect. In this paper, a home-made spray drying device was used to successfully synthesize LiFePO4with an average particle size of about 1 μm, and we studied the influence of spray drying temperature on the memory effect of LiFePO4in LIBs. The results showed that the increasing of spray drying temperature made the memory effect of LiFePO4strengthen from 1.3 mV to 2.9 mV, while the capacity decreased by approximately 6%. The XRD refinement and FTIR spectra indicate that the enhancement of memory effect can be attributed to the increment of Li–Fe dislocations. This work reveals the dependence of memory effect of LiFePO4on spray drying temperature, which will guide us to optimize the preparation process of electrode materials and improve the management system of LIBs.Keywords:LiFePO4;spray drying method;memory effect;cathode materials
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2018
·
IF 3.483
Haitao Zhuo,Zhankui Mei,Heng Chen,Shaojun Chen
In this contribution, shape memory polymers (SMPs) of chemically-crosslinked zwitterionic polyurethanes (CZPUs) were fabricated by crosslinking of the N,N-bis(2-hydroxyethyl) isonicotinamide (BINA)/hexamethylene diisocyanate (HDI) polyurethanes system by using pentaerythritol (PER), followed by zwitterionization with 1, 3-propanesultone (PS). As the zwitterionic units increased, it was found that the glass transition of hard phase in CZPUs remains constant while that of soft phase shifted at lower temperature, and a broad glass transition was obtained. The broad glass transition enables CZPUs to display triple, quadruple, and quintuple shape memory behaviours. Meanwhile, due to the chemically-crosslinked structure, the CZPUs exhibited an excellent shape fixation and recovery. Furthermore, the CZPU also exhibited good moisture-induced shape memory effect (SME) with a fast and high shape recovery observed below 70% RH and at 37 °C. The excellent thermally-induced multi-shape memory effect and moisture-induced shape memory effect enable CZPUs to be applied as smart materials for many applications among them the biomedical fields .
研究领域:
生物材料学
·
高分子科学
·
智能响应材料
·
组织工程
·
药物递送系统
·
再生医学
·
生物医学工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Yu Wu,Wenting Ji,Zhihua Xu,Yuqin Huang,De Li,Yuanchuan Li,Yong Chen
In Li-ion batteries (LIBs), the phenomenon of memory effect has only been found in a few two-phase electrode materials such as olivine LiFePO4, anatase TiO2, and Al-doped Li4Ti5O12, which is attributed to the Li-ion exchange between adjacent vacant Li and Fe sites in LiFePO4 and the Al-ion exchange between 8a and 16c sites in Al-doped Li4Ti5O12. Here, the Al-doped LiCrTiO4 was successfully synthesized by the spray-drying method and high-temperature sintering, which also exhibits the memory effect during only the charging process. The X-ray diffraction (XRD) and electrochemical results indicate that the saturated Al-doping level corresponds to the Al:Ti ratio of ca. 0.25 for LiCrTiO4, and the memory effect increases with the Al-doping level evidently. According to the in situ XRD and magic-angle spinning nuclear magnetic resonance results, the Al3+ ions are doped at the 8a sites, the Li ions hop between 8a and 16c sites during the charging and discharging processes, and the Li ions further hop from the 16c site to the 16d site after deeply discharging and move back in the subsequent charging process. Therefore, the memory effect of Al-doped LiCrTiO4 should originate from the reversible exchange of Li ions between 16c and 16d sites, and it is a common strategy to cause the memory effect in LIBs by inducing another reversible ionic migration in the electrode materials to affect the normal Li-ion extraction/insertion.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Siyao Chen,Jinping Li,Haofan Shi,Xuliang Chen,Guo Liu,Songhe Meng,Jian Lu
There is growing interest in additive manufacturing (AM) of ceramics due to the feasibility of achieving geometrically complex shapes for various engineering applications. Polymer-derived ceramics (PDCs), pyrolyzed from polymeric ceramic precursors, act as a competitive material for ceramic AM with advantages such as easy processability, flexible designability, and relatively low sintering temperature. However, the functionality of preceramic polymers is far from being fully exploited, thus restricting the development and applications of 3D printed ceramics. Herein, a novel multifunctional preceramic polymer composite with reconfigurability and shape memory effect is synthesized. By tuning the material compositions, the precursor inks suitable for 4D printing are pyrolyzed into lightweight self-shaping ceramics, allowing complex geometries to be fabricated. The preceramic polymers undergo a stepwise partial-to-full crosslinking process to form interpenetrating polymer networks , resulting in reconfigurability where the as-printed parts can be transformed into shapes with higher complexity. Unlike traditional precursors with static shapes, the precursor here possesses shape memory capability ( T g ∼ 95 °C). During the sintering process, the 3D printed precursor could successively undergo programmable active shape transformation with a high recovery ratio (∼100 %) and pyrolysis conversion into lightweight ceramics (1.05 g/cm 3 ). By exploring the semiconducting behavior of resulting ceramics, temperature sensors leveraging the advantages of reshaping are designed to detect the surface over a wide range (25–750 °C) with good conformability. The development of 4D printed reconfigurable and programmable precursors for the construction of complex ceramics enriches both the complexity and self-shaping capability of ceramics, allowing them to be applied as smart thermistors and deployable structures.
研究领域:
材料科学
·
智能材料
·
增材制造
✓ 已验证
产品关联
DOI
高影响因子
Smart Materials and Structures
·
2025
·Vol. 34
·期 9
·095019
·
IF 3.8
Shaojun Chen,Yonghang Zhang,Youhan Zeng,Yujie Deng,Haitao Zhuo,Haiqiang Zhong,Huaiping Zhang
Shape memory polymers (SMPs) are one of the most typical intelligent materials. However, the precise regulation of the shape memory effect (SME) remains a critical challenge in the field. This study introduces a simple strategy for regulating the SME, employing crystalline thermoplastic polyurethane (CTPU) as the raw material and utilizing isophorone diisocyanate (IPDI) trimer to regulate both one-way SME (1W-SME) and two-way SME (2W-SME). Results showed that incorporation of IPDI-trimer induced a cross-linked network within CTPU. The tensile strength at break reached a maximum of 27.4 MPa, and the elongation at break remained relatively high (2484%) when the IPDI-trimer content was below 10wt%. The resulting cross-linked CTPU exhibited exceptional one-way shape memory performance, achieving a 99.9% recovery rate and 96.4% fixation rate. Notably, switchable 2W-SME emerged when IPDI-trimer concentrations exceeded 11wt%. This dual SME functionality, coupled with a 54.3% actuation magnitude, signified a significant advancement in SMPs capabilities. Systematic analysis reveals that shape memory activation originates from the synergistic effects of oriented crystalline domain melting and energy release within the cross-linked network under thermal stimuli. The precise control of 1W-SME and 2W-SME demonstrated in this study fundamentally arises from regulated crystallinity and cross-linking degree of CTPU. Owing to these enhanced integrated properties, these materials show great promise for diverse applications, particularly in smart sensors and intelligent robotics.
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Shufen Zou,Ruihua Lv,Zaizai Tong,Bing Na,Kuan Fu,Hesheng Liu
We report the shape-memory PAA/PEO blends where in situ hydrogen-bonding complex and the excess PEO component serve as elastomer and switching element, respectively. The hydrogen bonding interactions between PAA and PEO are responsible for in situ PAA/PEO complex formation. The in situ PAA/PEO complex, water insoluble and highly elastic, is well interpenetrated with the excess crystalline PEO component to produce bi-continuous phase morphology. As a result, the blends ( wt PAA / wt PEO = 0.1 : 1 and 0.2 : 1), consisting of sufficient amount of in situ complex and the excess highly crystalline PEO, exhibit superior shape memory effects with a fixing and recovery ratio of nearly 100%.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Ceramics
·
2021
·Vol. 10
·期 2
·355-367
·
IF 6.707
Yang Weiyi,Chen Yan,Gao Shuang,Sang Licheng,Tao Ruoge,Sun Caixia,Shang Jian Ku,Li Qi
Photocatalysts with the photocatalytic “memory” effect could resolve the intrinsic activity loss of traditional photocatalysts when the light illumination is turned off. Due to the dual requirements of light absorption and energy storage/release functions, most previously reported photocatalysts with the photocatalytic “memory” effect were composite photocatalysts of two phase components, which may lose their performance due to gradually deteriorated interface conditions during their applications. In this work, a simple solvothermal process was developed to synthesize Bi 2 WO 6 microspheres constructed by aggregated nanoflakes. The pure phase Bi 2 WO 6 was found to possess the photocatalytic “memory” effect through the trapping and release of photogenerated electrons by the reversible chemical state change of W component in the (WO 4 ) 2− layers. When the illumination was switched off, Bi 2 WO 6 microspheres continuously produced H 2 O 2 in the dark as those trapped photogenerated electrons were gradually released to react with O 2 through the two-electron O 2 reduction process, resulting in the continuous disinfection of Escherichia coli bacteria in the dark through the photocatalytic “memory” effect. No deterioration of their cycling H 2 O 2 production performance in the dark was observed, which verified their stable photocatalytic “memory” effect.
研究领域:
材料科学
·
环境科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED MATERIALS
·
2023
·Vol. 35
·期 16
·2210753
·
IF 29.4
Yong Qi,Liujun Song,Changtong Zhou,Shufen Zhang
Shape-memory photonic crystals (SMPCs) transform the nanoscale deformation of copolymers into structural color through an undifferentiated response to stimuli; however, activatable selective responses are extremely rare. Herein, activatable dual confined shape-memory effects (CSMEs) derived from the remodeling of the interchain hydrogen bonds (H-bonds) in cold-programmable SMPCs are revealed. The first level is the water-triggered reconstruction of interchain H-bonds, which can activate/lock the collapsed skeleton, showing shape recovery/retention in response to ethanol vapor. The second level is the pressure-induced reorganization of interchain H-bonds that results in the recovered skeleton being locked even when exposed to ethanol vapor or water, while the background porous structure can switch between collapse and recovery. Dual CSMEs result from the Laplace pressure difference and the binding effect of interchain H-bonds in the skeleton according to insights of swelling, in situ deformation tracking, multidimensional infrared spectra, and water wetting/evaporation simulations. The signal interference, source code extraction, and color enhancement of structurally colored patterns can be implemented using CSMEs. This work opens up a new method for fabricating activatable responsive structural color and contributes to the expansion of nanophotonic technology in water printing, erasable watermarks, signal amplifiers, and information coding.
研究领域:
材料科学
·
纳米光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY
·
2023
·
IF 9
Qi Zhao,Zhao-Yang Chen,Xiao-Sen Li,Zhi-Ming Xia
The hydrate-based CO 2 capture and storage technique is cutting-edge and promising, but it exhibits slow formation rates and insufficient gas storage capacity, making commercialization challenging. In this work, the CO 2 hydrate formation process in fresh water, memory water, and saltwater systems under the electrostatic field was studied, and the influence mechanism of the electrostatic field on the CO 2 hydrate formation was discussed. Experimental results showed that the nucleation and growth of CO 2 hydrate could be affected by the electrostatic field. The nucleation of CO 2 hydrate could be promoted in the presence of an electrostatic field. In the fresh water system, the completion of hydrate formation was 54.5% faster with the 150 V application compared to the one without the electrostatic field. The introduction of an external electrostatic field causes a further reduction in the system's free energy. In the memory water system, the residual hydrate cage fragments could promote the reformation process of hydrate. Nevertheless, the presence of the electrostatic field could weaken the memory effect . In the salt water system, the electrostatic field could promote hydrate formation after the stage of dissolution. Due to the collision of ions with hydrate nuclei, however, the completion time of hydrate formation was increased. This study is anticipated to provide novel insights into the promotion of hydrate formation through the implementation of an electrostatic field.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·Vol. 141
·期 39
·e55993
·
IF 2.7
Haiyan Du,Rui Ding,Qing Xu,Jing Zhang,Dangchao Sun
The increasing demand for portable and flexible energy storage devices drives the rapid development of flexible electrodes and electrolytes. Meanwhile, the free-standing polymer electrodes face great chance and challenge. In this work, the stretchable and flexible polyaniline/carbon nanotube/poly(vinyl alcohol) electrode (PANI/CNT/PVA-E) was fabricated by in-situ polymerization of aniline in CNT/PVA-E substrate, where CNT was used to enhance the conductivity and mechanical properties of the polymer electrodes. Compared with PANI/PVA, the comprehensive performance of PANI/CNT/PVA-E was improved. In addition, the electrochemical performance and tensile property of the electrodes depended on the CNT content. The nanocomposite electrode with 0.25% of CNT possessed optimal properties with high capacitance of 248.69 mF cm −2 , and 75.29% of capacity retention over 4000 charge–discharge cycles at 1 mA cm −2 . It also exhibited outstanding tensile strength of 3.88 MPa and elongation up to 462.3%. Interestingly, the electrode possessed good heat driven shape memory effect. The temporary shape could be fixed at 70°C under extra force, and the fixed shape recovered within 10 s when it was reheated to the same temperature. It is concluded that the present work may contribute to the development and fabrication of flexible energy-storage devices, portable and highly stretchable electric devices.
研究领域:
材料科学
·
能源存储
·
柔性电子
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 42
·14826-14833
·
IF 7.059
Sijia Ren,Jiachun Feng
Water-responsive actuators have been of increasing interest in various applications. In this work, water-responsive actuators based on the bilayer composite film were prepared using commercialized PVA and SBS by a two-step solution casting method. In order to improve the adhesion between the PVA layer and SBS layer, SBS was firstly epoxidized to improve the polarity. Immediately after a thin film was formed on the surface of the epoxidized-SBS (E-SBS)/tetrahydrofuran solution, the PVA aqueous solution was poured onto the film and dried. It was found that the adhesive property between the two layers was improved and the adhesion strength reached 1005 kPa. The resultant bilayer film displayed the water-responsive two-way shape memory effect and exhibited excellent cyclic performance in five cycles. Flower-like and claw-like actuators based on the bilayer composite film were prepared and the actuation performance was demonstrated, suggesting their potential for applications in the fields of biomedicine and sensors.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）