查找使用阿拉丁产品的科研文献

Pickering water in oil emulsions prepared from biocompatible gliadin/ethyl cellulose complex particles

Fu-Zhen Zhou,Xin-Hao Yu,Dong-Hui Luo,Xiao-Quan Yang,Shou-Wei Yin

Water-in-oil (W/O) emulsions have gained interest in many fields, including food, healthcare, pharmaceutical, and agriculture . However, research on Pickering W/O emulsions is limited due to the lack of available stabilizers. This study aimed to demonstrate the development of edible Pickering W/O emulsions using biocompatible and biodegradable gliadin/ethyl cellulose complex particles (GECPs) with neutral hydrophobicity as the stabilizer. The characterizations of GECPs indicated that the particle size, contact angle, and dynamic interfacial tension could be adjusted by varying the gliadin-to-ethyl cellulose (EC) ratio. The investigations of emulsions revealed that the most stable emulsions were obtained when the gliadin-to-EC ratio was 2:1. Moreover, stable emulsions could be prepared at particle concentrations higher than 1.5%. The phase inversion of emulsions from W/O to O/W occurred at 55 wt% water. Confocal laser scanning microscopy and the theoretical calculations confirmed that GECPs formed multiple interfacial layers and acted as physical barriers against coalescence, thereby contributing to the stability of emulsions for at least 433 days; no reverse inversion occurred after 2.3 years of storage. This study provided a new approach to prepare stable Pickering W/O emulsions from GECPs. This strategy might open interesting avenues in solving the dilemma where Pickering stabilization using edible particles is required.

One-Pot Synthesis of Cellulose/MXene/PVA Foam for Efficient Methylene Blue Removal

Weisong Zhao,Hong Chi,Shiyun Zhang,Xue Zhang,Tianduo Li

Ti3C2TxMXene has attracted considerable interest as a new emerging two-dimensional material for environmental remediation due to its high adsorption capacity. However, its use is greatly limited by its poor mechanical properties, low processability and recyclability, and the low dispersity of such powder materials. In this work, a porous adsorbent (C–CMP) containing cellulose nanocrystals (CNC), Ti3C2TxMXene and polyvinyl alcohol (PVA) was prepared by a simple and environmentally-friendly foaming method. Glutaraldehyde was used as crosslinker to improve the mechanical properties and boost the adsorption efficiency of methylene blue (MB) molecules. Fourier transform infrared (FT–IR), elemental analysis (EDX) and thermogravimetric analysis (TGA) further confirmed that the preparation of the C–CMP foam and cross-linking reaction were successful. Scanning electron microscope (SEM) indicated that the macropores were distributed homogeneously. The adsorption experiment showed that maximum adsorption capacity of MB can reach 239.92 mg·g−1which was much higher than anionic dye (methyl orange, 45.25 mg·g−1). The adsorption behavior fitted well with the Langmuir isotherm and pseudo-second-order kinetic models. Thermodynamic analysis indicated that the adsorption process was spontaneous and endothermic. Based on FT–IR, EDX and X-ray photoelectron spectroscopy (XPS) analysis, the adsorption mechanism between C–CMP and MB molecules was attributed to electrostatic interaction.Keywords:foam;Ti3C2TxMXene;polyvinyl alcohol;cellulose nanocrystals;methylene blue;adsorption

Choline chloride-based deep eutectic solvent system as a pretreatment for microcrystalline cellulose

Sun Liangyun,Han Juan,Tang Chaofan,Wu Jiacong,Fang Sihan,Li Yuanyuan,Mao Yanli,Wang Lei,Wang Yun

As an effective substitute for ionic liquids (ILs), deep eutectic solvents (DESs) are known as a new generation of green solvents. In addition, DESs are considered to be the best solvents to replace traditional organic solvents and ILs due to their advantages of economy, simple preparation and biodegradability, which can be used to further break through the technical bottleneck in the field of biomass pretreatment. This study synthesized a series of choline chloride-based (ChCl-based) DESs and used them to pretreat microcrystalline cellulose (MCC) without dissolution, in order to achieve the purpose of improving the saccharification effect. DES-9 (ChCl/hydroquinone), DES-12 (ChCl/acetamide) and DES-16 (ChCl/acetic acid) were better pretreatment solvents. The optimum conditions for the pretreatment of MCC by DES-9 and DES-12 were both at 110 °C for 4 h, and the optimum condition of DES-16 was at 90 °C for 4 h. Compared with untreated MCC (26.66%), the saccharification yield of pretreated MCC with DES-16 increased by 20.5%. Finally, the structure and morphology changes of MCC before and after pretreatment were investigated in detail through the degree of polymerization (DP), SEM and enzyme adsorption. The results showed that DESs pretreatment made the surface of MCC become rough, which enhanced the accessibility of cellulose and enzymes, improving the saccharification effect. Graphical abstract

Cellulose bridged carbonate hydroxyapatite nanoparticles as novel adsorbents for efficient Cr(VI) removal

Jing Cui,Xinying Li,Shoucheng Ma,Wei Wei

Cellulose nanocrystal/phytic acid reinforced conductive hydrogels for antifreezing and antibacterial wearable sensors

Zhisen Wang,Zhengxin Ma,Shuaibing Wang,Menghan Pi,Xiaoyu Wang,Min Li,Honglang Lu,Wei Cui,Rong Ran

Common hydrogels containing abundant water are insulating materials and lose stretchability easily below the freezing point of water, holding limited potential in emerging applications such as wearable soft devices. The introduction of compatible biomass-derived materials into hydrogel systems could be a potential solution that simultaneously enables anti-freezing ability, mechanical enhancement, and antibacterial properties . Based on such a hypothesis, here we report the facile development of biocompatible hydrogels that are capable of maintaining satisfying mechanical properties and electrical conductivity well below zero degrees centigrade. The strategy is to reinforce neat polyacrylamide (PAAm) hydrogels with biomass-derived cellulose nanocrystal (CNC) and phytic acid (PA), transforming the originally weak, insulating hydrogels into tough, highly conductive ones. Anti-freezing and antibacterial properties also emerge in the reinforced hydrogels, enabling them to work as efficient wearable sensors below zero degrees centigrade. Considering that numerous polymer hydrogel systems are compatible with CNC and PA, we believe that this simple biomass-based strategy can work universally to enhance and functionalize various weak and insulating hydrogels that are traditionally susceptible to frost and bacteria.

Eco-friendly graphene-doped cellulose acetate superhydrophobic polymer for efficient oil-water separation

Shihao Wang,Zhuwei Gao,Xinyu Qi,Chengxin Li,Yuxin Xie,Xia Yang,Zhenlong Lin,Zhongxin Liu

In the field of oil-water separation, porous polymers with specific wettability have demonstrated great promise. Herein, we prepared a graphene-doped cellulose acetate porous polymer (graphene/CA) by thermally induced non-solvent induced phase separation (TINIPS) method. Wettability and oil absorption performance of graphene/CA-1.5 were studied with emphasis. The results showed that the water contact angle of graphene/CA-1.5 was 151°, while the oil contact angle was only 0°. As an adsorbent material, graphene/CA-1.5 could adsorb oils and organics such as soybean oil and CCl 4 from water, corresponding to a saturation capacity between 6.71 g/g and 14.72 g/g. Moreover, graphene/CA-1.5 remained stable hydrophobicity and oil absorption performance in environments such as strong acids, strong alkalis and extreme temperatures. Therefore, graphene/CA-1.5 is a potential adsorbent material for the treatment of oil pollution.

Glutaraldehyde-assisted crosslinking in regenerated cellulose films toward high dielectric and mechanical properties

Gao Meng-hang,Xie Xu,Huang Ting,Zhang Nan,Wang Yong

Developing the green dielectric materials satisfies the requirement of the sustainable development of society and economics. In this work, glutaraldehyde (GA)-assisted crosslinking strategy was developed to prepare the crosslinked regenerated cellulose (CRC) films, and the effects of different crosslinking methods, including crosslinking steps, concentration of GA solution and crosslinking time, on dielectric and mechanical properties of the CRC films were systematically investigated. Microstructure and morphology characterizations show that compared with the common RC films, the CRC films show apparently reduced defects and enhanced intermolecular interaction. At GA concentration of 6 vol% and crosslinking time of 30 min, the CRC film shows the lowest dielectric loss (0.03 at 1000 Hz, 92.3% smaller than RC film) and the highest breakdown strength (336.55 MV m −1 , 364.3% higher than RC film), and simultaneously, the film shows the high tensile strength of 76.8 MPa and excellent tensile modulus of 6.08 GPa, about 240.9% and 104% higher than those of the RC film, respectively. This work provides new insight in tailoring the dielectric and mechanical properties of the cellulose films through constructing the crosslinking structure, which is of great significance for the fabrication of the high-performance cellulose-based dielectric materials. Graphical abstract

Mineralization of phosphorylated cellulose/sodium alginate sponges as biomaterials for bone tissue engineering

Li Zha,Yahui Zheng,Jianfei Che,Yinghong Xiao

In recent years, the cellulose sponge has become an attractive material for bone tissue materials in tissue engineering. However, cellulose with hydroxyl groups shows weak apatite nucleation ability in simulated body fluid (SBF). In this study, cellulose/sodium alginate (SA) composite sponges were prepared via freeze-drying technique. The incorporation of SA in the cellulose matrix effectively increased the macroporous ability of composite scaffolds. Furthermore, the phosphate groups were grafted onto the surface of the composite sponges by esterification reaction in order to induce the formation of an apatite crystal. The morphology and structure were characterized by Fourier transform infrared spectrometer, scanning electron microscope, X-ray diffraction and X-ray photoelectron spectroscopy. The results showed that the deposition of apatite nanoparticles on the surface of phosphorylated composite sponges was very robust, and the spherical apatite nanoparticles were aggregated into rod-like apatite crystals. The Ca/P molar ratio of HA on the surface of the phosphorylated cellulose/SA composite sponge was 1.45. In addition, sponges with biocompatibility were demonstrated by CCK8 assay and Live/Dead fluorescence staining of L929 cells. The L929 cell activity of both cellulose/SA and phosphorylated cellulose/SA composite sponge extracts were higher than 80%. We draw a conclusion that the biocompatible mineralized phosphorylated cellulose/SA composite sponges show potential to be applied as a bone repair material.

Top-down fabrication of biodegradable multilayer tunicate cellulose films with controlled mechanical properties

Huang Da,Li Dong,Mo Kangwei,Xu Rui,Huang Yanan,Cui Yande,Zhang Qunchao,Chang Chunyu

Owing to non-degradable waste plastics causing serious environmental pollution, the development of natural polymeric materials has become an important topic. Herein, multilayer tunicate cellulose films (MTCFs) were fabricated by a top-down approach, where the alkali treated mantles of tunicate were layer-by-layer hot-pressed. Strong hydrogen bonds that formed between tunicate cellulose layers resulted in good interfacial compatibility of multilayer films. The as-prepared MTCFs exhibited improved thermal stabilities, excellent mechanical properties, and good degradability in natural soil. This work provided a top-down approach for the preparation of biodegradable multilayer films as packaging materials.

Flexible Ti3C2Tx MXene/PANI/Bacterial Cellulose Aerogel for e-Skins and Gas Sensing

Hui Zhi,Xiaobo Zhang,Fengya Wang,Peng Wan,Liang Feng

Flexible pressure sensors made of carbon materials have been used in electronic skins (e-skins), whose performance can be enhanced if composite sensing materials are used. Herein, an MXene/polyaniline/bacterial cellulose (MXene/PANI/BC) aerogel sensor has been fabricated through the self-assembly process between the MXene and one-dimensional active material. Combined with fewer-layer or single-layer MXenes, the as-fabricated aerogel could be used as the active layer of the pressure sensor, monitoring tiny motion signals of finger bending, wrist bending, and pulse beating. Bluetooth wireless transmission could also be realized to monitor the real-time spatial pressure distributions on the mobile phone, making the aerogel-based sensor an ideal candidate in e-skins. Meanwhile, the aerogel-based sensor is sensitive toward NH3 due to the unique three-dimensional (3D) structure of the aerogel and the abundant terminal groups (such as −O, −OH, and −F) of the MXene in the system that ensure efficient electronic transfer for the sensing process and create active sites for the absorption with the target gas. This work offers a versatile platform to develop MXenes to fabricate 3D composite aerogels for high-performance flexible multiple sensors.

Sustainable Cellulose Aerogel from Waste Cotton Fabric for High-Performance Solar Steam Generation

Huijie Liu,Md. Kowsar Alam,Mantang He,Ye Liu,Liming Wang,Xiaohong Qin,Jianyong Yu

The textile industry has been considered as one of the polluting industries, producing a large amount of textile waste and CO2 emissions each year. Recycling of waste fabric has attracted more research interest in recent years. Herein, renewable polydopamine (PDA)-functionalized cellulose aerogels (CAs) have been designed by a feasible and green way for clean water generation. With the polymerization of PDA on the surface, which possesses excellent photothermal conversion performance and water purification ability, the resulting CA could achieve a high light absorption of 96.5% with the evaporation rate of 2.74 kg m–2 h–1 under 1 sun. Meanwhile, the solar steam generator with the increasing height can absorb energy from adjacent ambient air to strengthen the vapor generation. The features of renewable CAs can achieve efficient water evaporation, which combined with their low material cost and recycling, offer promise in reducing not only energy consumption but also the environmental footprint of cotton textiles.

In situ synthesis of silver nanoparticles on dialdehyde cellulose as reliable SERS substrate

She Qiutian,Li Jie,Lu Yudong,Lin Shan,You Ruiyun

Dialdehyde cellulose (DAC) has considerable potential as an effective metal nanoparticle support material for the preparation of highly sensitive SERS substrates. In this study, a SERS substrate based on the Tollens reaction of DAC was successfully prepared. DAC was obtained by selective oxidation of cellulose nanocrystals (CNCs) with sodium periodate (NaIO 4 ). And the aldehyde group of DAC underwent REDOX reaction with Tollens reagent to produce silver nanoparticles (Ag NPs) on the DAC in situ. The SERS "hot spots" can be generated in the gaps of Ag NPs. The as-prepared DAC-Ag NP nanocomposites showed excellent SERS activity with a highly sensitive rhodamine 6 G detection limit of 10 –9  M. In diuron detection, an excellent linear relationship ( R 2  = 0.9948) was established between the concentrations of 10 –8  M to 10 –4  M. Furthermore, the feasibility of the proposed method in the actual samples was also confirmed. The substrate was applied to detect orange and persimmon peel which were previously treated with diuron solution. The substrate has universal applicability and is expected to be further applied in the detection of other hazardous molecules. Graphic abstract