Effect of subphase conditions on the formation of graphene Langmuir monolayer

This work was supported by grant from DAAD 4.9977.2017/5.2

Study of the surface microrelief of copper nanoparticles by the method of scanning probe microscopy

This work was supported by grants from the RFBR № 17-07-00407-а and № 17-32-50137-mol_nr

Investigation of copper nanoparticles by the method of scanning probe microscopy

В данной работе получали мицеллярный раствор с НЧ меди, стабилизированными ПАВ анионного типа — додецилсульфатом натрия (ДДС) C12H25NaO4S в щелочной среде при pH ≈ 10, в качестве восстановителя использовали гидразин гидрат (ГГ) N2H4∙H2O. Спектрофотометрическое исследование полученного раствора на спектрофотометре SHIMADZU UV-2550 в диапазоне длин волн 190-900 нм показало наличие пика поглощения излучения при длине волны 580 нм, соответствующего НЧ меди.In this work a micellar solution was prepared with copper NPs stabilized by an anionic surfactant — sodium dodecyl sulfate (SDS) C12H25NaO4S at pH ≈ 10. Hydrazine hydrate (HH) N2H4∙H2O was used as the reducing agent. Spectrophotometric study of the obtained solution by means of SHIMADZU UV-2550 spectrophotometer in the wavelength range 190-900 nm is showed the presence of a radiation absorption peak at 580 nm corresponding of copper NPs. The study of images of copper NPs on the glass substrates with an ITO layer (Indium Tin Oxide) was carried out by scanning probe microscopy (SPM) in atomic-force microscopy (AFM) and scanning tunneling microscopy (STM) by means of NanoEducator. The AFM images were obtained and the current-voltage characteristics of the copper NPs were recorded (Fig. 1 (a) and (б), respectively).Работа выполнена при финансовой поддержке гранта Российского научного фонда (проект №14-12-00275) и Национального исследовательского Саратовского государственного университета

Monitoring of copper nanoparticle penetration into dentin of human tooth in vitro

Study of the penetration depth of synthesized copper nanoparticles into cut samples of human dentin was conducted. The scanning electron microscopy was used to determine the elemental composition of fresh transverse cleavage of the dentin cut for determination of the copper nanoparticles penetration with an effective antiseptic effect. The morphology of the cut surface of the dentin of a human tooth was studied and the lower limit of the diffusion boundary was determined. It was found that copper nanoparticles penetrate into the dentin cut to a depth of ~ 1.8 μm with the diffusion coefficient of 1.8×10–11 cm2/s. Despite the rather small size of the synthesized copper nanoparticles (20-80 nm), a rather small penetration depth can be explained by the high aggregation ability of copper nanoparticles, as well as the ability of a micellar solution of sodium dodecyl sulfate, in which nanoparticles were stabilized, to form conglomerates in micelles of much larger sizes