Ultrafine Au and Ag Nanoparticles Synthesized from Self‐Assembled Peptide Fibers and Their Excellent Catalytic Activity

The self‐assembly of an amphiphilic peptide molecule to form nanofibers facilitated by Ag⁺ ions was investigated. Ultrafine AgNPs (NPs=nanoparticles) with an average size of 1.67 nm were synthesized in situ along the fibers due to the weak reducibility of the ‐SH group on the peptide molecule. By adding NaBH₄ to the peptide solution, ultrafine AgNPs and AuNPs were synthesized with an average size of 1.35 and 1.18 nm, respectively. The AuNPs, AgNPs, and AgNPs/nanofibers all exhibited excellent catalytic activity toward the reduction of 4‐nitrophenol, with turnover frequency (TOF) values of 720, 188, and 96 h^?1, respectively. Three dyes were selected for catalytic degradation by the prepared nanoparticles and the nanoparticles showed selective catalysis activity toward the different dyes. It was a surprising discovery that the ultrafine AuNPs in this work had an extremely high catalytic activity toward methylene blue, with a reaction rate constant of 0.21 s^?1 and a TOF value of 1899 h^?1.     

Development of Tough Thermoplastic Elastomers by Leveraging Rigid–Flexible Supramolecular Segment Interplays

Supramolecular interactions facilitate the development of tough multifunctional thermoplastic elastomers. However, the fundamental principles that govern supramolecular toughening are barely understood, and the rational design to achieve the desired high toughness remains daunting. Herein, we report a simple and robust method for toughening thermoplastic elastomers by rationally tailoring hard–soft phase separation structures containing rigid and flexible supramolecular segments. The introduced functional segments with distinct structural rigidities provide mismatched supramolecular interactions to efficiently tune the energy dissipation and bear an external load. The optimal supramolecular elastomer containing aromatic amide and acylsemicarbazide moieties demonstrates a record toughness (1.2 GJ m⁻³), extraordinary crack tolerance (fracture energy 282.5 kJ m⁻²), an ultrahigh true stress at break (2.3 GPa), good elasticity, healing ability, recyclability, and impact resistance. The toughening mechanism is validated by testing various elastomers, confirming the potential for designing and developing super-tough supramolecular materials with promising applications in aerospace and electronics.     

Synthesis of water-soluble carbon nanotubes via surface initiated redox polymerization and their tribological properties as water-based lubricant additive

Polyacrylamide (PAM)-grafted multi-walled carbon nanotubes (MWCNTs-g-PAM) which are dispersable in water were prepared by the surface initiated redox polymerization of acrylamide using ceric ammonium nitrate (CAN) as initiator. They are soluble in polar solvents such as water, tetrahydrofuran and acetone. The chemical structure of the resulting product and the quantities of grafted polymer were determined by FT-IR, TGA. TEM, and FE-SEM observations indicated that the nanotubes were coated with a PAM layer, exhibiting core-shell nanostructures, with the PAM chains as a brush-like or hairy shell, and the MWCNTs as a hard backbone. Furthermore, the tribological properties of the prepared MWCNTs-g-PAM composites as an additive in water were evaluated with a four-ball machine. The results confirmed that the composites exhibit good anti-wear and friction reduction properties as well as load-carrying capacity. This was attributed to the possibility of the composites acting as nanometer sized tiny bearings during lubrication.     

In situ FT-IR spectroscopy investigations of carbon nanotubes supported Co-Mo catalysts for selective hydrodesulfurization of FCC gasoline

To better understand the nature of carbon nanotubes supported Co-Mo catalysts （Co-Mo/CNTs） for selective hydrodesulfurization （HDS） of fluid catalytic cracking （FCC） gasoline, studies are carried out using in situ Fourier transform infrared spectroscopy （FT-IR）. The catalytic performances of Co-Mo/CNTs catalysts were evaluated with a mixture of cyclohexane, diisobutylene, cyclohexene, 1-octene （60 ： 30 ： 5 ： 5, volume ratio） and thiophene （0.5%, ratio of total weight） as model compounds to simulate FCC gasoline. The HDS experimental results suggested that the HDS activity and selectivity of Co-Mo/CNTs catalysts were affected by Co/Mo ratio; the optimal Co/Mo atomic ratio is about 0.4, and the optimum reaction temperature is 260 ℃. The in situ FT-IR studies revealed that 1-octene can be completely saturated at 200 ℃. In the FT-IR spectra of diisobutylene, the characteristic absorption peak around 3081 cm^-1 for the stretching vibration peak of =C-H bond was still clear at 320 ℃ indicating that diisobutylene is difficult to be hydrogenated. As for the thiophene, no characteristic absorption peak could be found around 3092 cm^-1 and 835 cm^-1 when the reaction temperature was raised to 280 ℃, indicating that thiophene had been completely hydrodesulfurized. On the basis of FT-IR results, it can be deduced that thiophene HDS reaction occurred mainly through direct hydrogenolysis route, whereas thiophene HDS and diisobutylene hydrogenation reaction over Co-Mo/CNTs catalysts might occur on two different kinds of active sites.     

化学类专业一流课程建设的思路与重点——以山东大学物理化学一流课程建设为例

First-class course construction is the foundation of first-class undergraduate education construction. Based on the understanding of the "Two properties and one degree" standard of first-class course, key characteristics of the first-class course construction are summarized as accurate positioning, clear teaching goals, good construction foundation, advanced pedagogy, first-class construction, remarkable effectiveness and preferential demonstration. Taking the construction of first-class physical chemistry course in Shandong University as an example, the course orientation, the determination of teaching objectives and the design and implementation of the teaching are introduced. The practice and experience of the course construction are demonstrated in five aspects as first-class foundation, first-class teachers, first-class resources, first-class pedagogical ideas and first-class achievements. It can be used as the reference for the future construction of first-class courses in other universities.     

GMP-quadruplex-based hydrogels stabilized by lanthanide ions

This work describes the gelation behaviors and properties of a biological molecule, guanosine 5′-monophosphate disodium salt(GMP), in the presence of trivalent lanthanide ions. Hydrogels composed of GMP-quadruplexes were prepared by adjusting p H,through which the protonation of phosphate group was controlled to tune the interactions between lanthanide ions and GMP.Within the p H region of 2–6, the electrostatic interaction between lanthanide ions and phosphate group is hindered and the cation-dipole interaction acts as the main driving force for the formation of G-quadruplexes. All the hydrogels were found consisting of three-dimensional network of the intertwining one-dimensional nanofibers formed by the stacking G-quartets induced by lanthanide ions. A significant fluorescence enhancement of thioflavin T(Th T), a fluorescent molecule, was found to be triggered by the G-quadruplex structures, for which the rotation of chromophoric groups on Th T molecules were prohibited due to the implant into the G-quadruplex structures.     

银杏叶挥发油化学成分的研究

本文采用气相色谱以及气相色谱-质谱（GC－MS）联用技术对银杏挥发油的化学成分进行了研究，初步鉴定出其中的17种化合物。研究表明，挥发油中棕润酸和2，6-二特丁基-4-甲基苯酚的含量较高。     

NMR波谱技术在两亲分子聚集体研究中的应用

NMR technologies such as relaxation, self-diffusion coefficient and other NMR methods were reviewed. The results of NMR measurements, especially, on 1H, 13C, 19F-NMR spectra and quadrupolar echo of 2H-NMR spectra on self-assembled properties and structures have been obtained. The investigations on the self-assembly of amphiphiles and the transition of self assembled structures were introduced and the determination of NMR measurements on micelles, vesicles and microemulsions was summed.     

Gold and silver nanorings formed at the air/water interface

Gold nanorings were prepared at the air/water interface through reduction of AuCl₄⁻ ions by UV-light irradiation or formaldehyde gas treatment at room temperature templated by thin films of phthalocyanine derivatives. Silver nanorings were produced at the air/water interface via reduction of Ag⁺ ions by UV-light irradiation templated by poly(9-vinylcarbazole) (PVK) thin films. These nanostructures were investigated by transmission electron microscopy (TEM), selective-area electron diffractometry (SAED), and high-resolution TEM (HRTEM). It was found that the gold nanorings are composed of close-packed nanoplates whose (1 1 0) crystal planes are parallel to the air/water interface; while silver rings are composed of nanoparticles. It is demonstrated that the ring-like aggregates formed by parallel linear supramolecules of the phthalocyanine derivatives and the ring-like structure of PVK supramolecules are responsible for the formation of the gold and silver nanorings, respectively.