Pt/十六烷基三甲基溴化铵纳米聚集体修饰玻碳电极促进析氢(英文)

A novel, cost-effective, and simple electrocatalyst based on a Pt-modified glassy carbon electrode(GCE), using cetyltrimethylammonium bromide(CTAB) as a cationic surfactant, is reported. Amphiphilic CTAB molecules were adsorbed on GCE by immersion in a CTAB solution. The positively charged hydrophilic layer, which consisted of small aggregates of average size less than 100 nm,was used for accumulation and complexation of [PtCl2. anions by immersing the electrode in Ksolution. The modified electrode was characterized using scanning electron microscopy,energy-dispersive X-ray spectroscopy, impedance spectroscopy, and electrochemical methods. The electrocatalytic activity of the Pt particles in the hydrogen evolution reaction(HER) was investigated.The results show that the CTAB surfactant enhances the electrocatalytic activity of the Pt particles in the HER in acidic solution.

Surface charge induced tuning of electrical properties of CVD assisted graphene and functionalized graphene sheets

We demonstrate a new approach to tune the electrical properties of graphene and functionalized graphene. Graphene was synthesized using thermal chemical vapour deposition(TCVD) method on copper foil using precursor gas acetylene and co-catalyst H2 gas. TCVD assisted graphene was successfully transferred onto a silicon wafer. Transferred graphene sheet was then functionalized to prepare graphene oxide(GO) and reduced graphene oxide(rGO). Different surface charge carbon nanoparticles, e.g. carbon nanoparticle with net positive charge and carbon nanoparticle with net negative charge were then immobilized on transferred graphene and functionalized graphene sheets. The functionalized graphene and charge mobilized functionalized graphene were characterized by Uv–vis spectroscopy,Fourier transformed infrared spectroscopy, scanning electron microscopy, and Raman spectroscopy. After immobilization of carbon nanomaterials, the ac electrical conductivity was found to increase due to enhancement of the surface charge, electron density, and mobility. It was observed that negative surface charge immobilized graphene and functionalized graphene show higher conductivity. Thus, the electrical property of graphene and functionalized graphene can be tuned by surface modification with different surface charge carbon nanomaterials.

Vascular-confined multi-passage discoidal nanoconstructs for the low-dose docetaxel inhibition of triple-negative breast cancer growth

Taxane efficacy in triple negative breast cancer(TNBC)is limited by insufficient tumor accumulation and severe off-target effects.Nanomedicines offer a unique opportunity to enhance the anti-cancer potency of this drug.Here,1,000 nm×400 nm discoidal polymeric nanoconstructs(DPN)encapsulating docetaxel(DTXL)and the near infrared compound Iipid-Cy5 were engineered.DPN were obtained by filling multiple times cylindrical wells in a poly(vinyl alcohol)template with a polymer mixture comprising poly(lactic-co-glycolic acid)(PLGA)and poly(ethylene glycol)diacrylate(PEG-DA)chains together with therapeutic and imaging agents.The resulting“multi-passage”DPN exhibited higher DTXL loading,Iipid-Cy5 stability,and stiffness as compared to the conventional"single-passage"approach.Confocal microscopy confirmed that DTXL-DPN were not taken up by MDA-MB-231 cells but would rather sit next to the cell membrane and slowly release DTXL thereof.Empty DPN had no toxicity on TNBC cells,whereas DTXL-DPN presented a cytotoxic potential comparable to free DTXL(IC_(50)=2.6 nM±1.0 nM vs.7.0 nM±1.09 nM at 72 h).In orthotopic murine models,DPN accumulated in TNBC more efficiently than free-DTXL.With only 2 mg/kg DTXL,intravenously administered every 2 days for a total of 13 treatments,DTXL-DPN induced tumor regression and were associated to an overall 80%survival rate as opposed to a 30%survival rate for free-DTXL,at 120 days.All untreated mice succumbed before 90 days.Collectively,this data demonstrates that vascular confined multi-passage DPN,biomimicking the behavior of circulating platelets,can efficiently deliver chemotherapeutic molecules to malignant tissues and effectively treat orthotopic TNBC at minimal taxane doses.

An Investigation into the Magnetic Properties of Nickel Nano-grains Synthesized Via Thermal Decomposition Techniques

Nickel nanoparticles were synthesized through the thermal decomposition of nickel（II） acetylacetonate in con- junction with the two methods of hot-injection and heating-up at elevated temperatures in alkylamine. Using several mole ratios of the oleic acid, different morphologies were obtained. The synthesized particles were characterized via XRD, SEM, TEM, SAED and EDAX. Mean particle size was revealed to range from 25 to 45 nm. Presence of crystallized particles in HCP with little FCC phases was also confirmed with XRD patterns. Magnetic hysteresis loops measured by the VSM showed that the magnetic properties of Ni nanoparticles （i.e., coercivity, saturation magnetization and relative permeability） were much enhanced in comparison with the bulk.