铂金首饰助力后疫情时代的珠宝行业复苏

以亲密关系及人生重要时刻为契机,让消费者用铂金见证情感并表达个人态度,助力销售迅速反弹,并为后疫情时代的持续增长创造强大平台。尽管铂金首饰的消费决策极大地取决于消费者自身,且市场份额相对较小,但这并不影响柏金成为在由新冠疫情造成的消费下行趋势中率先逆流而上的首饰品类之一。     

新生代情侣爱情观洞察

随着世代更迭,当新生代逐步成为社会主流消费人群,他们的爱情观也成为了当下的热议话题。新生代追随真心,忠于自我;新生代内心坚定,渴望心灵契合的“灵魂伴侣”;新生代注重浪漫也遵循现实,爱得纯粹且坚定。为此,国际铂金协会(PGI■)携手Ipsos开展“新生代民族志研究”,并以此发起关于新生代爱情观的洞察,一起探寻他们的爱情箴言。     

Mechanical and thermal properties of gamma irradiated ethylene propylene diene monomer rubber/vermiculite clay/maleic anhydride composites

Vermiculite clay (VMT) was first treated with 2 M of hydrochloric acid. The VMT, before and after acid‐treatment, was characterized by X‐ray diffraction (XRD) and transmission electron microscopy. The untreated (VMT) and acid‐treated vermiculite clay DVMT) at different contents (2.5–10 phr) and maleic anhydride (MA) at different contents (3–10 phr) were mixed with ethylene polyethylene diene rubber (EPDM) via direct melt compounding in an internal mixer. The mechanical and thermal properties of gamma irradiated composites were studied. The results indicated that the physical properties of gamma irradiated EPDM/DVMT/MA nanocomposites were greatly improved after loading with either DVMT or MA. The improvement was achieved when the content of DVMT clay was 5 phr, MA 7 phr and irradiation dose at 75 kGy. J. VINYL ADDIT. TECHNOL., 25:E3–E11, 2019. © 2018 Society of Plastics Engineers     

Thermal and physicomechanical properties of gamma‐irradiated EPDM/waste newsprint microfibers composites treated using acrylic styrene emulsion as a coupling agent

This investigation deals mainly with thermal stability and crosslinking density of EPDM/newsprint microfibers composites. The recycled newsprint microfibers were treated using a different ratio of acrylic styrene emulsion (5, 10, and 15 wt% fiber) as a bonding agent to reinforce EPDM rubber matrix. The effect of microfibers content, namely, 5 up to 50 phr (part per hundred part of rubber) and the effect of ionizing radiation on EPDM/newsprint microfibers composites properties were investigated. The microfibers structure and EPDM/microfibers composite were investigated using X‐ray diffraction and FTIR analysis; the results indicate that bonding has occurred between the treated newsprint microfibers and EPDM polymer matrix. EPDM/untreated newsprint microfibers composites have achieved higher crosslinking density than EPDM matrix up to 50 phr microfibers content and up to 100 kGy then decreased with increasing gamma irradiation dose. Meanwhile treatment of the microfibers using 10 wt% acrylic styrene leads to improve crosslinking density at any microfibers content. Thermogravimetric analysis (TGA) was carried out for the microfibers and their composites. TGA indicated that the thermal stability of microfiber was enhanced using acrylic styrene. Whereas there is a slight improvement in thermal stability and activation energy of the composites due to adding treated microfibers using 10 phr microfiber content treated using10 wt% acrylic styrene emulsion and irradiated with 60 kGy gamma radiation dose. J. VINYL ADDIT. TECHNOL., 25:E91–E106, 2019. © 2018 Society of Plastics Engineers     

Full Gamut Wall Tunability from Persistent Micelle Templates via Ex Situ Hydrolysis

The predictive self‐assembly of tunable nanostructures is of great utility for broad nanomaterial investigations and applications. The use of equilibrium‐based approaches however prevents independent feature size control. Kinetic‐controlled methods such as persistent micelle templates (PMTs) overcome this limitation and maintain constant pore size by imposing a large thermodynamic barrier to chain exchange. Thus, the wall thickness is independently adjusted via addition of material precursors to PMTs. Prior PMT demonstrations added water‐reactive material precursors directly to aqueous micelle solutions. That approach depletes the thermodynamic barrier to chain exchange and thus limits the amount of material added under PMT‐control. Here, an ex situ hydrolysis method is developed for TiO₂ that mitigates this depletion of water and nearly decouples materials chemistry from micelle control. This enables the widest reported PMT range (M:T = 1.6–4.0), spanning the gamut from sparse walls to nearly isolated pores with ≈2 Å precision adjustment. This high‐resolution nanomaterial series exhibits monotonic trends where PMT confinement within increasing wall‐thickness leads to larger crystallites and an increasing extent of lithiation, reaching Li_0.66TiO₂. The increasing extent of lithiation with increasing anatase crystallite dimensions is attributed to the size‐dependent strain mismatch of anatase and bronze polymorph mixtures.     

Monitoring of Removal of Organochlorine/Fluorine Pesticides from Water Using Graphene Composites by Gas Chromatography/Mass Spectrometry

Three nanoparticles’ materials are prepared, characterized and their performance was evaluated for efficient removal of five organochlorine, one organofluorine and six different kinds of bacteria. Gas chromatography/mass spectroscopy have been used to monitor the pesticides concentration before and after treatment by these prepared materials. Graphene gives the most efficient removal of these pesticides than graphene–silver composite but the later is more efficient for remediation of water contaminated with different kinds of bacteria.     

Short polyethylene terephthalate fiber (PET) reinforced NBR rubber composites

Acrylonitrile-butadiene rubber (NBR) has been reinforced with different content of PET up to 25 phr. Vulcanization of prepared composites as will as the unreinforced ones have been induced by ionizing radiation of accelerated electron beam of varying dose up to 150 kGy. Evaluations of the vulcanized composites have been followed up through the measurement of mechanical, physical and thermal properties. Also, scanning electron microscope (SEM) was performed. Mechanical properties, namely tensile strength (TS) and hardness were found to increase with the increase of irradiation dose as well as the increase in the content of PET up to 25 phr. Also, elongation at break (ε _b) was found to decrease with the increase of irradiation dose; however, the decrease in ε_b is not consistence with the increase in fibers loading. Young’s modulus (E) and tensile modulus at 25% elongation (E25) were found to increase with the increase of irradiation dose and fiber loading up to 20 phr. Also, the volume fraction of swollen rubber increases as irradiation dose and/or fiber content increased; it was more influenced by irradiation rather than fiber loading. Anisotropic swelling increased with irradiation and fiber loading up to 20 phr. SEM photomicrograph showed that irradiation causes adhesion between PET fiber and NBR where less pulling out and less pitting on the surface were observed. The thermal properties of the composite irradiated at 100 kGy reveal that the activation energy (E _a) increases up to 10 phr fiber content. When the composite that contains 10 phr fiber irradiated at doses higher than100 kGy, Ea decreased.     

Corrosion inhibitors : Part II: Quantum chemical studies on the corrosion inhibitions of steel in acidic medium by some triazole, oxadiazole and thiadiazole derivatives

The corrosion inhibition efficiencies of some triazole, oxadiazole and thiadiazole derivatives for steel in presence of acidic medium have been studied by using AM1, PM3, MINDO/3 and MNDO semi-empirical SCF molecular orbital methods. Geometric structures, total negative charge on the molecule (TNC), highest occupied molecular energy level (E_HOMO), lowest unoccupied molecular energy level (E_LUMO), core-core repulsion (CCR), dipole moment (μ) and linear solvation energy terms, molecular volume (V_i) and dipolar-polarization (π^*), were correlated to corrosion inhibition efficiency. Four equations were proposed to calculate corrosion inhibition efficiency. The agreement with the experimental data was found to be satisfactory; the standard deviations between the calculated and experimental results ranged between ±0.03 and ±4.18. The inhibition efficiency was closely related to orbital energies (E_HOMO and E_LUMO) and μ. The correlation between quantum parameters and experimental inhibition efficiency has been validated by single point calculations for the semi-empirical AM1 structures using B3LYP/6-31G^** as a higher level of theory. The proposed equations were applied to predict the corrosion inhibition efficiency of some related structures to select molecules of possible activity from a presumable library of compounds.