查找使用阿拉丁产品的科研文献

An environment-friendly process of lead recovery from spent lead paste

Tianzu Yang,Boyi Xie,Weifeng Liu,Duchao Zhang,Lin Chen

Spent lead paste, an important secondary resource, calls for recycling at the request of both environmental protection and the sustainable development of lead industry. An environment-friendly process to recover lead from spent lead paste was proposed. The impurities Sb, Ca, Fe and Cu in spent lead paste were firstly removed by H 2 SO 4 at the leaching rate of 92.22%, 86.43%, 87.89% and 94.04%, respectively. And then, 99.9% of PbO 2 in spent lead paste was reduced to PbO by the hydrothermal reduction process with glucose as the reductant. In the process of hydrothermal desulfurization by NaOH, 99.46% of S in the reduced lead paste was removed and then the lead paste was converted into a single phase of 3PbO·H 2 O. Finally, metallic lead, with a purity of 99.978%, was obtained from the single-phase lead paste by a low-temperature reduction smelting process with starch as the reductant under the conditions of Na 2 O/B 2 O 3  = 1/2, PbO/B 2 O 3  = 5/1, starch/PbO = 1/7.5, smelting temperature 700 °C, and smelting duration 90 min, and the lead recovery is high up to 95.53%. Compared with the traditional lead smelting technology, the smelting temperature was reduced from 1200 °C to 700 °C, helping greatly reduce the energy consumption. The process proposed in this paper guides a new development direction for the utilization of spent lead paste.

An architectural exfoliated-graphene carbon aerogel with superhydrophobicity and efficient selectivity

Yutong Lu,Huiqing Wang,Yun Lu

In the study, in order to completely utilize the advantages of graphene monolayer, nano-fibrillated cellulose with cations from polyethyleneimine (PEI) was used as the intercalator to efficiently exfoliate the reduced graphene oxide into a single layer with a thickness about 0.47 nm by means of ionic attraction. After the high-temperature treatment (800 °C), the carbon aerogel (NC-GO@NFC) with an architectural structure was manufactured by combining 2D monolayer graphene with 1D nano-fibrillated cellulose. The pore volume (0.55 cm 3 /g) and specific surface area (441 m 2 /g) of NC-GO@NFC were about two times higher than those of GO carbon aerogel. Particularly, the buoyant porous aerogel showed superhydrophobicity with a large water contact angle (155.5°) due to the increase of -NH- and C C as well as the pyrolysis of hydrophilic groups. The superhydrophobicity endows the aerogel with an exceptional oil/water separation performance. The carbon aerogels exhibited the adsorption capability towards many organic phases (including lubricating oil and some organic solvents). In addition, the efficient continuous removal and collection of organic solvents (methylbenzene) from water surface was achieved by a designed water/oil pump device. Therefore, the recyclable 3D porous composite aerogel had the application potential as organic solvent adsorbents and oil/water separation agents.

Interfacial Diffusion Printing: An Efficient Manufacturing Technique for Artificial Tubular Grafts

You Zhou,Qinyuan Gui,Wenyuan Yu,Shenglong Liao,Yonglin He,Xinglei Tao,Yang Yu,Yapei Wang

Despite great progresses in bioprinting materials and technologies, immense challenges still remain when printing tubular tissues or organs with satisfying mechanical and chemical properties, such as blood vessel, colon, and trachea. Herein, a promising extrusion system based on an interfacial diffusion printing (IDP) technique for one-step printing of tubular tissue grafts is proposed. Specifically, this technique offers great convenience to prepare hollow hydrogel fibers with excellent mechanical properties and satisfactory biocompatibility. The tubular diameter can be readily adjusted within 6 mm, which renders the possibility of these hydrogel tubes to serve as small-diameter vascular grafts. In the model of animal trials, the hydrogel grafts with the capability of enduring arterial pressure are mechanically stable in rabbit carotid artery replacement. Because of its intrinsic simplicity and generality, the IDP technique is considered to be one of the reliable choices for more complicated bioengineering.

An acetone gas sensor based on nanosized Pt-loaded Fe2O3 nanocubes

Shendan Zhang,Mingjie Yang,Kunyu Liang,Ayse Turak,Bingxue Zhang,Da Meng,Chuanxi Wang,Fengdong Qu,Wenlong Cheng,Minghui Yang

Nanosized Pt-loaded Fe 2 O 3 nanocubes are prepared through, successively, a simple hydrothermal reaction, two-step annealing process and finally reduction with NaBH 4 of H 2 PtCl 4 . The resultant Pt decorated Fe 2 O 3 nanocubes, made up of Fe 2 O 3 nanoplatelets, are hierarchical, hollow and porous, with an average edge length of 200–300 nm. The sensor based on Pt decorated Fe 2 O 3 nanocomposites exhibits higher response (R air /R gas  = 25.7) to 100 ppm of acetone gas at lower temperature (139 °C), with a short response-recovery time (3 s/22 s), compared with pure Fe 2 O 3 nanocubes sensor. The Pt-Fe 2 O 3 nanocomposite sensor shows excellent potential to act as a low cost, low temperature sensor for acetone gas, with high acetone selectivity under high humidity conditions and with the interference of other gases. Under various environmental conditions designed to mimic exhaled air, the sensor is able to detect ppb amounts of acetone, with high repeatability and stability, making it suitable for applications such as oral diabetic sensors. The attractive chemical and electronic sensitizations of partially oxidized Pt nanoparticles are responsible for the enhancement of acetone sensing performance. Based on the high acetone selectivity, high stability and fast dynamic response, the Pt enhanced Fe 2 O 3 nanocubes sensor is an exceptionally suitable candidate for a low cost acetone sensor, and the proposed approach provides a route to develop gas sensors that can operate at low temperatures for a wide variety of applications.

Chiral CdSe nanoplatelets as an ultrasensitive probe for lead ion sensing

Xiongbin Wang,Junjie Hao,Jiaji Cheng,Junzi Li,Jun Miao,Ruxue Li,Yiwen Li,Jiagen Li,Yuhui Liu,Xi Zhu,Yanjun Liu,Xiao Wei Sun,Zikang Tang,Marie-Hélène Delville,Tingchao He,Rui Chen

As opposed to traditional photoluminescence and ultra-violet based optical sensing, we present here a sensing system based on resolved optically active polarization with promising applications. It is based on the ultrathin CdSe nanoplatelets (NPLs) when modified with either L or D-cysteine molecules (L/D-cys) as bio-to-nano ligands. The chiral ligand transfers its chiroptical activity to the achiral nanoplatelets with an anisotropy factor of ∼10−4, which unlocks the chiral excitonic transitions and allows lead ion detection with a limit of detection (LOD) as low as 4.9 nM. Simulations and modelling based on time-dependent density functional theory (TD-DFT) reveal the chiral mechanism of L/D-cys capped CdSe NPLs. The presented CD-based sensing system illustrates an alternative possibility of using chiral CdSe NPLs as competitive chiral sensors for heavy metal ion detection.

PCSK9 Hapten Multicopy Displayed onto Carrier Protein Nanoparticle: An Antiatherosclerosis Vaccine

Shasha You,Xiaoyu Guo,Xiaomei Xue,Yongyong Li,Haiqing Dong,Haiying Ji,Ting Hong,Yazhong Wei,Xueyin Shi,Bin He

In recent years, various vaccination strategies have shed new light on the treatment of atherosclerosis. Proprotein convertase subtilisin/Kexin type 9 (PCSK9) is a hot target in the development of antiatherosclerosis vaccine. However, the efficacy of conventional PCSK9 is largely limited by poor immunogenicity and low hapten density. Therefore, we hypothesized whether a nanostructure synthesized by self-assembled carrier protein accompanied by multicopy hapten display could improve the efficacy of vaccine. In this study, bovine serum albumin (BSA) was self-assembled into sub-100 nm nanoparticles via an intermolecular disulfide network as the inner core. Then, sequences of PCSK9 were conjugated onto the surface of nanoparticles by “click” chemistry to consequently form an orderly structured of nanovaccine with repetitive hapten display. Compared with conventional PCSK9 peptide vaccine, our immunization study demonstrated that the PCSK9 multicopy display nanovaccine (PMCDN) was able to induce higher titers of PCSK9 antibody and more efficient lymph node drainage and improve endocytosis by antigen presenting cells.

An electromagnetic wave absorbing material with potential application prospects—WS2 nanosheets

Deqing Zhang,Tingting Liu,Shuang Liang,Jixing Chai,Xiuying Yang,Junye Cheng,Hao Wang,Maosheng Cao

In this study, we report two-dimensional WS2 nanosheets successfully synthesized by simple hydrothermal method. The obtained WS2 nanosheets are very promising as electromagnetic wave absorbers. The phase composition, microstructure, electromagnetic properties and microwave absorption properties of the prepared WS2 nanosheets were characterized by XRD, SEM, TEM, XPS and vector network analyzers. Our results show that the real and imaginary parts of permittivity of WS2 prepared at 210 °C are higher than those of other samples, with maximum interfacial polarization and dielectric loss, a wide effective absorption band with a thinner thickness is obtained in the frequency range of 5.5–18 GHz. The effective absorption bandwidth can reach 12.5 GHz, the highest reflection loss of the sample wax containing 40% WS2 is –15.6 dB at a thickness of 5.5 mm, and the absolute value of RL is greater than 10 dB in the range of 2.0–5.5 mm. The results show that the prepared WS2 nanosheets have the advantages of wide bandwidth, strong absorption and light weight, and have potential application prospects in the application and development of microwave absorbing materials in the future.

A study on 85Kr measurement with an internal gas proportional counter

Chao-Feng Chen,Li-Tao Yang,Yan-Jun Huang,Zhi-Hong Shang-Guan,Gui-Ying Guo,Jian-Lin Yao,Xiang-Dong Sha

A measurement method of 85 Kr using an internal gas proportional counter (IGPC) is presented in this study. The operation conditions of the IGPC were determined and optimized, including the operating voltage, pressure, sample volume, interference from other gas components such as nitrogen or air, and mitigation of the memory effect. The IGPC was calibrated using certified standards, and the detection efficiency was approximately 58% for typical samples. A lower limit of detection of approximately 0.11 MBq/m 3 (Kr) was achieved after counting for 5 h with 1 mL pure Kr, corresponding to the atmospheric activity concentration of 0.18 Bq/m 3 (air). It was shown that the IGPC could be used effectively for measuring 85 Kr.

Trace Determination of Arsenite With an Ionophore-Coated Selective Micro Sensor

Li Wang,Wenshuai Lu,Gaoshan Jing,Tianhong Cui

Hyperbranched PdRu nanospine assemblies: an efficient electrocatalyst for formic acid oxidation

Hongjing Wang,Yinghao Li,Chunjie Li,Ziqiang Wang,You Xu,Xiaonian Li,Hairong Xue,Liang Wang

Highly branched Pd-based nanocrystals are very attractive materials for electrocatalytic formic acid oxidation (FAO). Herein, a very simple synthetic method is proposed for preparing unique bi-metallic PdRu nanospine assemblies (PdRu NSAs) in high yield. The self-supported PdRu NSAs assembled by staggered nanospines show superior catalytic activity and durability for FAO, owing to their hyperbranched nanoarchitectures and bimetallic compositions. Different from the traditional multi-step routes, the proposed one-step synthetic method is very valuable for fabricating hyperbranched Pd-based catalysts with designed compositions and desired performances.

Surface Modification of Polyamide 6,6 Fabrics with an Alkaline Protease – Subtilisin

Setara Begum,Jindan Wu,Carrington M. Takawira,Jiping Wang

Subtilisin treatment is feasible in benign conditions, and yields a clean, dynamic approach for Polyamide 6,6 (PA 6,6) modification. In this study, the water contact angle (WCA) method, capillary height and moisture regain were used measure hydrophilicity. To characterization the modification, the scanning electron microscope (SEM), amino group quantification and x-ray photoelectron spectrometry (XPS) were used. Fabric burst strength and hand properties were characterized. Optimum conditions for subtilisin treatment were found to be 55oC, neutral pH with 10% (owf) enzyme concentration for a fixed 90 min treatment period. X-ray photoelectron spectrometry (XPS) results showed that carboxyl groups were produced on the modified fiber surface. The modified fibers showed much improved hydrophilicity as indicated by reduced wicking time, improved capillary height and moisture regain percentage. The creation of carboxylic acid group sand increased number of amino groups detected on the fabric surface may positively influence hydrophilicity. In comparison to harsh alkali modification, the enzyme treatment led to smaller weight loss. In general, enzymatic treatments- a more eco-friendly alternative to alkaline treatments, resulted in a significant improvement in surface properties of PA 6,6 fabrics.

Cationic nanoparticle as an inhibitor of cell-free DNA-induced inflammation

Liang Huiyi,Peng Bo,Dong Cong,Liu Lixin,Mao Jiaji,Wei Song,Wang Xinlu,Xu Hanshi,Shen Jun,Mao Hai-Quan,Gao Xiaohu,Leong Kam W.,Chen Yongming

Cell-free DNA (cfDNA) released from damaged or dead cells can activate DNA sensors that exacerbate the pathogenesis of rheumatoid arthritis (RA). Here we show that ~40 nm cationic nanoparticles (cNP) can scavenge cfDNA derived from RA patients and inhibit the activation of primary synovial fluid monocytes and fibroblast-like synoviocytes. Using clinical scoring, micro-CT images, MRI, and histology, we show that intravenous injection of cNP into a CpG-induced mouse model or collagen-induced arthritis rat model can relieve RA symptoms including ankle and tissue swelling, and bone and cartilage damage. This culminates in the manifestation of partial mobility recovery of the treated rats in a rotational cage test. Mechanistic studies on intracellular trafficking and biodistribution of cNP, as well as measurement of cytokine expression in the joints and cfDNA levels in systemic circulation and inflamed joints also correlate with therapeutic outcomes. This work suggests a new direction of nanomedicine in treating inflammatory diseases.