电解铜箔表面电沉积Zn-Ni-P-La合金工艺

为了缓解我国高性能铜箔依靠进口的局面,进行了将类金属(P)和稀土金属(La)引入电解铜箔锌镍合金镀层中以获得高耐腐蚀性铜箔的实验。 利用电子能谱(XPS)、X射线衍射(XRD)、扫描电子显微镜(SEM)等技术手段分析镀层质量。 在最佳工艺下获得非晶态Zn-Ni-P-La合金镀层,镀层表面平整均匀、结晶致密,未钝化的情况下,铜箔镀件在180 ℃烘箱中保持1 h不变色,表现出较理想的抗氧化和抗腐蚀能力。 表明镀层中适量的P和稀土La对改善镀层质量有着重要的作用,具有较好的工业应用前景。     

Ultrathin Alternating Copolymer Nanotubes with Readily Tunable Surface Functionalities

Well‐defined ultrathin nanotubes (30 nm in diameter and of micrometer‐scale length) were generated through the self‐assembly of a novel alternative copolymer synthesized using an epoxy–thiol click‐chemistry reaction. The self‐assembly mechanism was investigated both by experiments and using dissipative particle dynamics (DPD) simulations. The obtained nanotubes can be readily functionalized with carboxy groups, amino groups, peptides, or other groups by simple modular click copolymerization.     

Guest‐Induced Transformation of a Porphyrin‐Edged FeII4L6 Capsule into a CuIFeII2L4 Fullerene Receptor

The combination of a bent diamino(nickel(II) porphyrin) with 2‐formylpyridine and Fe^II yielded an Fe^II₄L₆ cage. Upon treatment with the fullerenes C₆₀ or C₇₀, this cage was found to transform into a new host–guest complex incorporating three Fe^II centers and four porphyrin ligands, in an arrangement that is hypothesized to maximize π interactions between the porphyrin units of the host and the fullerene guest bound within its central cavity. The new complex shows coordinative unsaturation at one of the Fe^II centers as the result of the incommensurate metal‐to‐ligand ratio, which enabled the preparation of a heterometallic cone‐shaped Cu^IFe^II₂L₄ adduct of C₆₀ or C₇₀.     

A Universal equipment for biaxial stretching of polymer films

A biaxial stretching equipment was designed and constructed to enable fundamental studies of the relationship between film processing conditions and structures of oriented film products. With programmable drive motors and scissorlike mechanism, all stretching modes, including uniaxial stretching with constant and free width, simultaneous and sequential biaxial stretching, can be applied to a square-shaped sheet. Parameters related to film stretching manufacturing, such as temperature, draw ratio and stretching speed can be set independently to meet the requirement of different polymers. The force information during stretching is recorded by two miniature tension sensors in two directions independently, which can monitor the mechanical stimulus and stress response. Using this equipment, experiments are conducted to investigate the influence of stretching parameters on the structure of polypropylene films, which provides an effective method to tailor the processing conditions to obtain the films with desired properties.     

Sr_2CeO_4:Nd~(3+)纳米粒子的合成和近红外发光

采用甘氨酸-硝酸盐燃烧法制备了Sr2CeO4和Sr2CeO4:Nd3+发光纳米粒子。样品的结构及性质采用XRD,TEM,荧光光谱及荧光衰减曲线等进行表征。在1200℃煅烧1h能够得到均匀的类球形Sr2CeO4:Nd3+纳米粒子,其粒径大小为20~40nm,并具有良好的分散性和高效的近红外发光特性。Nd3+合适掺杂浓度为0.15%(摩尔分数)。对Sr2CeO4:Nd3+近红外发光的机制分析表明:通过基质Sr2CeO4吸收紫外光,基团CeO4发生了电荷转移达到激发态,并将激发态能量传递给了Nd3+,从而使Sr2CeO4:Nd3+产生了特征的近红外发射。     

Diaminodiacid Bridges to Improve Folding and Tune the Bioactivity of Disulfide‐Rich Peptides

Disulfide‐rich peptides containing three or more disulfide bonds are promising therapeutic and diagnostic agents, but their preparation is often limited by the tedious and low‐yielding folding process. We found that a single cystine‐to‐diaminodiacid replacement could significantly increase the folding efficiency of disulfide‐rich peptides and thus improve their production yields. The practicality of this strategy was demonstrated by the synthesis and folding of derivatives of the μ‐conotoxin SIIIA, the preclinical hormone hepcidin, and the trypsin inhibitor EETI‐II. NMR and X‐ray crystallography studies confirmed that these derivatives of disulfide‐rich peptide retained the correct three‐dimensional conformations. Moreover, the cystine‐to‐diaminodiacid replacement enabled structural tuning, thereby leading to an EETI‐II derivative with higher bioactivity than the native peptide.     

Synthesis of Carbon/Sulfur Nanolaminates by Electrochemical Extraction of Titanium from Ti2SC

Herein we electrochemically and selectively extract Ti from the MAX phase Ti₂SC to form carbon/sulfur (C/S) nanolaminates at room temperature. The products are composed of multi‐layers of C/S flakes, with predominantly amorphous and some graphene‐like structures. Covalent bonding between C and S is observed in the nanolaminates, which render the latter promising candidates as electrode materials for Li‐S batteries. We also show that it is possible to extract Ti from other MAX phases, such as Ti₃AlC₂ , Ti₃SnC₂ , and Ti₂GeC, suggesting that electrochemical etching can be a powerful method to selectively extract the “M” elements from the MAX phases, to produce “AX” layered structures, that cannot be made otherwise. The latter hold promise for a variety of applications, such as energy storage, catalysis, etc.     

Multifunctional Nano‐Bioprobes Based on Rattle‐Structured Upconverting Luminescent Nanoparticles

Lanthanide‐doped upconversion nanoparticles (UCNPs) have shown great promise in versatile bioapplications. For the first time, organosilica‐shelled β‐NaLuF₄:Gd/Yb/Er nanoprobes with a rattle structure have been designed for dual‐modal imaging and photodynamic therapy (PDT). Benefiting from the unique rattle structure and aromatic framework, these nanoprobes are endowed with a high loading capacity and the disaggregation effect of photosensitizers. After loading of β‐carboxyphthalocyanine zinc or rose Bengal into the nanoprobes, we achieved higher energy transfer efficiency from UCNPs to photosensitizers as compared to those with conventional core–shell structure or with pure‐silica shell, which facilitates a large production of singlet oxygen and thus an enhanced PDT efficacy. We demonstrated the use of these nanoprobes in proof‐of‐concept X‐ray computed tomography (CT) and UC imaging, thus revealing the great potential of this multifunctional material as an excellent nanoplatform for cancer theranostics.