查找使用阿拉丁产品的科研文献

Construction of high-strength p(HEMA-co-AA) fluorescent hydrogels based on modified carbon dots as chemically crosslinkers

Wang Jianying,Ma Xiaofei,Wei Lai,Zhu Xiang,Zhu Yuhua,Wang Gang,Mei Tao,Li Jinhua,Wang Xianbao

A novel kind of p(HEMA-co-AA) fluorescent hydrogels with high strength are first generated through one-step photopolymerization of 2-hydroxyethyl methacrylate (HEMA), acrylic acid (AA), and HEMA-modified carbon dots (HMCDs). Herein, HMCDs are used as new nontoxic fluorescent crosslinking centers. The novel HMCDs-based fluorescent hydrogels not only display stable photoluminescence, but have high mechanical strength. The fluorescent properties of the HMCDs-based hydrogel films are similar as that of CDs solution and stable for a prolonged duration. Besides, the fluorescent intensity of HMCDs-based hydrogels can be changed by controlling the HMCD content. The tensile strength of the fluorescent hydrogels with 1 wt% HMCD content can reach up to ~ 12 MPa, higher than that of the conventional hydrogels. More importantly, the mechanical properties can be adjusted by changing the water content and HMCD content. The enhanced mechanical strength is probably attributed to the relatively ordered hierarchical microstructure.

A convenient approach by using poly-(HEMA-co-NIPAM)/Cu2+ solution sol–gel transition for wound protection and healing

Yansong Wang,Xin Chu,Yu Sun,Peng Teng,Tianzhi Xia,Yisheng Chen

Rapid and convenient wound healing is crucial for reducing potential post-traumatic wound complications. In this study, a temperature-sensitive polymer of poly-(HEMA-co-NIPAM) (PHN) was synthesized by free-radical polymerization, in which the solution quickly underwent a sol–gel transition above 29°C, thus responding to a typical body temperature and facilitating wound sealing. PHN solution incorporated with copper ions (PHN-Cu) not only exhibited excellent antibacterial properties, but also expedited wound closure and facilitated tissue angiogenesis. The in vivo and in vitro experiments showed that the PHN-Cu had a higher wound closure rate and demonstrated an ability to promote skin tissue angiogenesis. Such a versatile, convenient aqueous solution could enable nonprofessionals to promptly treat wounds in a short time after injury, thus providing suitable conditions for later treatment, and can be used as a convenient method to clean wounds.

High-strength p(HEMA-co-AA) hydrogels with photoluminescence crosslinked by 2-hydroxyethyl methacrylate modified silica/carbon dots colloids

Wei Lai,Wang Jun,Arshad Naila,Wang Jianying

2-Hydroxyethyl methacrylate (HEMA) improved colloids of silica/carbon dots (SiO2/HMCDs) were used by means of new translucent, nontoxic cross-linking centers comprising two non-toxic components, silica colloids and carbon dots. The direct photopolymerization of a mixture of acrylic acid (AA), HEMA, and SiO2/HMCDs afforded ultrahigh strength and mechanically robust hydrogel. The fabricated fluorescent SiO2/HMCDs-based hydrogels demonstrated stable photoluminescence owing to their outstanding mechanical flexibility. Fluorescent hydrogels exhibited tensile strength of up to ∼ 13.2 MPa by processing with 1 wt% SiO2/HMCDs content. More importantly, the mechanical properties (stress or strain) could be changed by controlling the content of SiO2/HMCDs and H2O. Relative hierarchical structure attributed to high mechanical strength.

Application of HEMA-AAm copolymer to achieve faster optical tissue transparency for 2D/3D fluorescence imaging

Ma Hui,Qin Ruixiu,Yao Qiufeng,Li Yier,Cong Xingshun,Wu Wenhui,Zhao Qi,Ye Hua,Wu Kefeng

Optical transparency methods can facilitate biological tissue optical imaging, which enabled accurate three-dimensional (3D) signal visualization and quantification of complex biological structures. Unfortunately, existing optical clearing approaches present a compromise between maximizing clearing capability, the preservation of fluorescent protein emission and the speed of sample processing. To address this challenge, we synthesis of a 2-hydroxyethyl methacrylate (HEMA)-acrylamide (AAm) copolymer using antipyrine (ATP) and 2,2′-thiodiethanol (TDE) as solvent, which could embed tissue samples rapidly and highly transparent, and compatible with multiple fluorescence labeling. It can enable volumetric imaging of tissue up to the scale of mice organs, shrinkage duration of the clearing and preserve emission from fluorescent proteins and dyes. This copolymer with suitable toughness and plasticity allows the tissue of interest to be sectioned into thin slices, and histological techniques provide high-resolution two-dimensional (2D) images of cells and subcellular structures. Furthermore, HEMA-AAm copolymer -tissue transparent could distinguish cell structures between healthy and diabetic disease in dye-labeled liver tissues, which provides new insights into pathological diagnosis and analysis. Copolymer provides an environment to facilitate high-resolution 3D/2D fluorescence imaging, which enables the study of cellular and tissue morphology in experimental and clinical conditions of interest.

Highly Sensitive Optical Fiber Pb2+ Concentration Sensor Based on HEMA/AM/SA Interpenetrating Polymer Network (IPN) Hydrogel

Ning Wang,Ming He,Longjiao Wang,Chuanjie Lei,Linyufan Xiao,Yingjie Li,Shuan Liu

An optical fiber sensor based on a HEMA/AM/SA interpenetrating polymer network (IPN) hydrogel is proposed for monitoring the concentration of Pb2+. The Fabry–Perot interference cavity is constructed from a single-mode fiber, a ceramic ferrule, and an IPN hydrogel layer. P (HEMA co AM)/SA IPN hydrogel films were prepared by a step-by-step crosslinking method, which had good mechanical properties, swelling properties, and Pb2+adsorption capacity. The Pb2+concentration changes cause the interference spectrum shift of the sensor. By monitoring the wavelength shift under different Pb2+concentrations, the sensor sensitivity in the range of 0~1 ppm Pb2+concentration in solution is 5.0743 nm/ppm with 0.994 linearity. The influence of different proportions of IPN hydrogel on the performance of the sensor was studied. In the range of 10–90% HEMA, higher sensitivity is obtained by a small weight ratio of HEMA/AM. The sensor stability, repeatability, selectivity, dynamic response, and temperature response are also investigated in experiments. Experimental results demonstrate that the proposed sensor exhibits good stability, sensitivity, repeatability, and selectivity. Owing to its compact structure, straightforward fabrication, low cost, and good sensing performance, this sensor shows strong potential for application in monitoring Pb2+concentrations.

The synthesis and co-micellization of PCL-P(HEMA/HEMA-LA) and PCL-P(HEMA/HEMA-FA) as shell cross-linked drug carriers with target/redox properties

Fan Chen,Yi Li,Ye Fu,Yu Hou,Yuanwei Chen,Xianglin Luo

High efficient protocol for the modification of polyethersulfone membranes with anticoagulant and antifouling properties via in situ cross-linked copolymerization

Hui Qin,Chuangchao Sun,Chao He,Dongsheng Wang,Chong Cheng,Shengqiang Nie,Shudong Sun,Changsheng Zhao

In this paper, we provide a highly efficient, convenient and universal protocol for blood-compatible modification of polyethersulfone (PES) membranes via in situ cross-linked copolymerization of 2-hydroxyethl methacrylate (HEMA) and acrylic acid (AA) in PES solutions. Static water contact angle, protein adsorption, platelet adhesion, and clotting time of the modified PES membranes are systematically studied, and the results indicate that the modified membranes show improved hydrophilicity, good blood anticoagulant and antifouling properties after introducing HEMA and AA. Meanwhile, the modified membranes perform low contact activation and complement activation when they come in contact with blood. The effect of the HEMA/AA ratios on the blood compatibility is also investigated to identify the different roles played by HEMA and AA in the modification; the HEMA could more effectively enhance the membrane antifouling property, while the AA could more effectively improve the anticoagulant property. The results indicated that the blood-compatible PES membranes prepared via the in situ cross-linked copolymerization had potential to be used in the field of blood purification.

Amphiphilic PDMS-HEMA membrane surface for improved gas selectivity and blood compatibility

Xiujuan Zhang,Xinlu Zhang,Bangyao Du,Xiaokun Wang,Xuehua Ruan,Wenji Zheng,Yan Dai,Minggang Guo,Gaohong He

While extracorporeal oxygenation (ECMO) is regarded as the golden weapon for patients with cardiopulmonary failure in critical care, its clinical use is usually complicated by the blood coagulation on the hydrophobic surface of the artificial membrane for gas exchange. Herein, amphiphilic polydimethylsiloxane‐hydroxyethyl methacrylate (PDMS-HEMA) material was firstly synthesized from chemical reaction between HEMA and the vinyl group on the side chains of PDMS via a simple process, and then coated on the microporous polyethersulfone (PES) base membrane to obtain PDMS-HEMA/PES composite membrane . Structure characterizations demonstrated that HEMA and PDMS were successfully copolymerized, and PDMS-HEMA/PES composite membranes were well prepared with a flat dense PDMS-HEMA layer coated on the surface of microporous PES substrate. Surface property analyses confirmed much smoother membrane surface, phase-separated morphology, and significant decrement in water contact angles for PDMS-HEMA obtained. More importantly, the PDMS-HEMA/PES composite membrane exhibited a CO 2 /O 2 gas selectivity of ∼6.5 in comparison to ∼5.5 of PDMS/PES, indicating improved gas exchange efficiency. Nevertheless, the PDMS-HEMA/PES composite membrane also displayed excellent and much improved performance in hemocompatibility and long-term stability for storage as well as against blood wetting. Therefore, side-chain modification of hydrophobic PDMS with hydrophilic HEMA through simple chemical copolymerization process is an easy and feasible method to make the membrane surface with long-term amphiphilicity less thrombogenic in contact with blood and more efficient in gas exchanges.

Modification Mechanisms and Properties of Poplar Wood via Grafting with 2-Hydroxyethyl Methacrylate/N,N′-methylenebis(acrylamide) onto Cell Walls

Jihang Hu,Xiaoqing Wang

As the only renewable resource among the four basic materials (steel, cement, plastic, wood), wood itself and wood products have a “low carbon” value and play an important role in storing carbon. The moisture absorption and expansion properties of wood limit its application scope and shorten its service life. To enhance the mechanical and physical properties of fast-growing poplars, an eco-friendly modification procedure has been used. This was accomplished by the in situ modification of wood cell walls by vacuum pressure impregnation with a reaction of water-soluble 2-hydroxyethyl methacrylate (HEMA) and N,N’-methylenebis(acrylamide) (MBA). The anti-swelling efficiency of HEMA/MBA-treated wood was improved (up to 61.13%), whereas HEMA/MBA-treated wood presented a lower weight-gain rate (WG) and water-absorption rate (WAR). It was observed that the modulus of elasticity, hardness, density, and other properties of modified wood had improved significantly, as indicated by XRD analysis. Modifiers diffuse primarily within cell walls and cell interstices of wood, causing crosslinks between the modifiers and the cell walls, reducing its hydroxyl content and blocking the channels for water movement, thereby enhancing its physical properties. This result can be obtained by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDX), Nitrogen adsorption test imaging ATR-FTIR (Attenuated total reflection-Fourier-Transform Infrared) Spectroscopy, and nuclear magnetic resonance (NMR) and Nitrogen adsorption test. Overall, this straightforward, high-performance modification method is crucial for maximizing wood’s efficiency and the sustainable development of human society.Keywords:wood modification;reaction mechanism;cell walls;grafting;properties

Preparation of Superhydrophobic PVDF/P(HEMA-MMA-SMA)/SiO2 Composite Membranes by Electrospinning

Hu Yuanxia,Ma Jinghong,Gong Jinghua

The hydrophobic random copolymer P(HEMA-MMA-SMA) which contained 2-hydroxyethyl methacrylate (HEMA), methyl methacrylate (MMA) and stearyl methacrylate (SMA) chains was successfully synthesized via radical polymerization. The composites membranes of poly (vinylidene fluoride) (PVDF) and P(HEMA-MMA-SMA) blends and PVDF/P(HEMA-MMA-SMA)/SiO 2 were prepared by electrospinning. Scanning Electron Microscopy (SEM) and Water Contact Angle (WCA) revealed that morphology and hydrophobic properties of the membrane surface. With the condition of 12 wt% SiO 2 , the maximum WCA (154°) of the electrospun composite film can be obtained. Superhydrophobic materials have been widely used in the fields, such as oil-water separation and self-cleaning. Keywords Methacrylate Poly(vinylidene fluoride) SiO 2 Random copolymer Blends Superhydrophobic Electrospinning Membranes

Determination of Propagation Rate Coefficients of 2-Hydroxyethyl Methacrylate in Aqueous Solution

Yuxiao Li,Wentao Liu,Kan Liu,Qingyue Wang,Xiaohui Li,Erlita Mastan,Yuanfeng Wu,Pingwei Liu,Bo Peng,Khak Ho Lim,Wen-Jun Wang

Mechanistic understanding of free radical polymerization (FRP) in aqueous solution is hindered by the lack of kinetic coefficient data. Here, we investigated the propagation rate coefficient ( k p ) for FRP of HEMA in aqueous solution. The k p at 80 °C increased by 6 times as the monomer weight fraction in aqueous system decreases from 100 wt.% to 6 wt.%, that is., from 6.0 × 10 3 to 3.3 × 10 4 L·moL −1 ·s −1 . This increase in k p is associated with the increase in pre-exponential factor ( A ), which suggests an increase in entropy with increasing water molecules in the polymerization system. To investigate the effect of solvent on k p , pulse-laser polymerization in solvents of different hydrogen bonding affinity, that is, 50 wt.% butyl propionate (BP) and dimethyl formamide (DMF), are conducted. The k p obtained are in order of k p , bulk ∼ k p , BP > k p , DMF , suggesting that the intermolecular hydrogen bonding at carbonyl moieties critically affects the geometry of transition state quasi-equilibrium in propagation. We underpinned this observation by analyzing the carbonyl and alkene moieties of HEMA in different solvents using infrared (IR) spectroscopy. The mechanistic analyses and insights relating to hydrogen bonding and functional moieties can be relevant for future studies involving non-aqueous solvents promoting hydrogen bonds.

Interpenetrated polymer networks in composites with poly(vinyl alcohol), micro- and nano-fibrillated cellulose (M/NFC) and polyHEMA to develop packaging materials

Bai Huiyu,Li Yufei,Wang Wei,Chen Guangliang,Rojas Orlando J.,Dong Weifu,Liu Xiaoya

A novel method for the preparation of composites based on poly(vinyl alcohol) (PVA) and micro- and nano-fibrillated cellulose (M/NFC) is reported. The addition of crosslinking HEMA monomers and a photo-initiator enabled the formation of an interpenetrated polymer network that displayed enhanced interfacial adhesion and dispersion of (M/NFC) in the matrix. Photo-crosslinked PVA/(M/NFC)/polyHEMA composite films produced by casting followed by UV polymerization of HEMA were characterized by using several approaches. These included Fourier transform infrared and UV–Vis spectroscopies, differential scanning calorimetry, X-ray diffractometry, thermogravimetric analysis and dynamic mechanical analysis. The thermo-mechanical and optical properties as well as water absorption and vapor barrier abilities of the developed photo-crosslinked PVA/(M/NFC)/polyHEMA films were measured and the benefit of photo-crosslinking determined. The major degradation peak of photo-crosslinked PVA/(M/NFC)/polyHEMA composites increased substantially compared to that of the PVA/(M/NFC) system (from ~300 to ~350 °C). The water vapor permeability of PVA/(M/NFC)/polyHEMA composite films was reduced with HEMA loading (5.44 × 10 −11 , 5.10 × 10 −11 , 4.12 × 10 −11 , 4.31 × 10 −11  g/m h Pa for 0, 5, 10 and 15 % HEMA, respectively). Overall, a new and facile method for the synthesis of PVA/(M/NFC)-based composite networks interpenetrated with cross-linked poly(HEMA) is demonstrated, offering excellent prospects for packaging applications.