AFM-based approach to establish structure/property type correlations for polymeric functional materials

This work was supported by the RSF (project No. 18-19-00453) and the RFBR (project No. 18-08-01356 A)

Atomic force microscopy in polymeric chemistry’s studies

This work was supported by the RSF (project No. 18-19-00453)

An atomic force microscopy study of hybrid polymeric membranes: Surface topographical analysis and estimation of pore size distribution

© 2016, Pleiades Publishing, Ltd.The surface morphology of polymeric membranes as organic–inorganic block copolymers has been studied by atomic force microscopy (AFM). These hybrid block copolymers have been obtained by the polyaddition of toluene 2,4-diisocyanate to macroinitiators and the addition of oligomeric polyhedral оctaglycidyl silsesquioxane (Gl-POSS) as a bulky branching agent in a concentration range of 0.1–15 wt %. The AFM study of the morphology made it possible to determine the main roughness parameters and to perform topographical analysis of the surface of the polymers. The pore size distribution was evaluated by histogrammic approximation with the use of the Gauss distribution. The hypothesis of the normalcy of distribution of the experimental sample of pore diameters was confirmed by a combined criterion and Pearson’s chi-square goodness-of-fit test. The effect of the Gl-POSS concentration on the surface morphology and the microstructure of the organic–inorganic polymeric membranes was found to be nonmonotonic over the test concentration range

Synthesis of Decorated Carbon Structures with Encapsulated Components by Low-Voltage Electric Discharge Treatment

Abstract: Polycondensation of complexes of chloromethanes with triphenylphosphine by the action of low-voltage electric discharges in the liquid phase gives nanosized solid products. The elemental composition involving the generation of element distribution maps (scanning electron microscopy–energy dispersive X‑ray spectroscopy mapping) and the component composition (by direct evolved gas analysis–mass spectrometry) of the solid products have been studied. The elemental and component compositions of the result-ing structures vary widely depending on the chlorine content in the substrate and on the amount of triphenylphosphine taken. Thermal desorption analysis revealed abnormal behavior of HCl and benzene present in the solid products. In thermal desorption spectra, these components appear at an uncharacteristically high temperature. The observed anomaly in the behavior of HCl is due to HCl binding into a complex of the solid anion HCI-2 with triphenyl(chloromethyl)phosphonium chloride, which requires a relatively high temperature (up to 800 K) to decompose. The abnormal behavior of benzene is associated with its encapsulated state in nanostructures. The appearance of benzene begins at 650 K and continues up to temperatures above 1300 K. © 2022, The Author(s).The work was carried out with the equipment of the "Modern Nanotechnologies" Ural Shared-Use Center at the Ural Federal University. The study was supported by the Russian Foundation for Basic Research, project no. 18-29-24008

Efficacy of regional analgesia techniques in abdominal surgery patients with obesity

Abstract The use of regional anesthetic techniques in abdominal surgery is an essential component of the multimodal approach to perioperative analgesia, yet data on their use in obese patients remains limited. The aim of this study is to determine the effectiveness of the epidural analgesia (EA) and the transversus abdominis plane block (TAP-block) in laparoscopic obese patients, as well as to evaluate the possibility of using the rectus sheath block (RSB) as a “rescue” anesthetic technique after laparotomy in obese patients. Materials and methods. The data on the 102 obese patients operated on esophageal hiatal diaphramgmatic hernia, colon tumor, postoperative ventral hernia, morbid obesity and choledocholithiasis were analyzed. In laparoscopic surgery 20 patients received EA (EA group), 21 patients – TAP-block (TAP group), 21 patients – opioids and non-steroidal anti-inflammatory drugs (NSAIDs) without any regional anesthesia techniques (group TIVA1). In laparotomic surgery 16 patients received RSB (RSB group) and 24 patients – only opioids and NSAIDs (TIVA2 group). After the surgery the following was estimated: the time of extubation, the total dose of opioids, the level of pain according to the 10-point numeric range score (NRS), the incidence of dyspnea using the monitor Utas 300 (Ukraine), the incidence of postoperative nausea and vomiting (PONV), the time of active patient mobilization, and the level of satisfaction with analgetic regimen. For the RSB group, the complexity of the RSB and the mean time to achieve adequate analgesia (pain intensity ≤3 points per NRS) were determined additionally. The statistical analysis was performed using the Statistica for Windows version 6.0 software. Results. In the EA group, the intraoperative dose of fentanyl was twice lower, and patients were extubated two times faster than in the TAP, TIVA1, RSB, TIVA2 groups (P < 0.05). At the same time, none of the patients in the EA group required the restoration of neuromuscular conduction with neostigmine (P < 0.05). After the surgery, the pain level was 2–3 times higher in the TIVA1, RSB, and TIVA2 groups than in the EA and TAP groups (P < 0.05). “Rescue” analgesia in the RSB group was performed from the first attempt in all the patients in 5–10 minutes and provided an adequate effect in 3 (2–4) min. The complexity level of RSB was defined as “easy” in 12 (75 %) patients, as “average” in 4 (25 %) patients (P < 0.05). The incidence of dyspnea and opioid doses after surgery in the EA, TAP and RSB groups of patients were 2 times lower, and the incidence of PONV was 3 to 4 times lower than in the TIVA1 and TIVA2 patients’ groups (P < 0.05). In the EA and TAP groups, patients became mobile after 8–13 hours after surgery, in the group TIVA1 – after 16–22 hours, in the group RSB – after 18–36 hours, in the group TIVA2 – after 48–96 hours (P < 0.05). 100 % of the respondents from the EA, TAP and RSB groups were satisfied with the analgesic regimen at the “excellent – good” level. In the TIVA1 and TIVA2 groups, 20–25 % of respondents identified analgesic comfort as “good”, 60–65 % of respondents – as “satisfactorily”, about 15 % of respondents – as “unsatisfactorily” (P < 0.05). Conclusions. In laparoscopic surgery the use of EA or TAP-block in obese patients significantly reduces the level of postoperative pain, the need for opioids, the incidence of dyspnea and PONV, which leads to the possibility of patients’ mobilization within 8–13 hours after surgery. After laparotomic surgery in obese patients RSB effectively “rescues” from pain and prevents excessive use of opioids, which reduces the number of adverse reactions and increases satisfaction with the quality of analgesia

Atomic force microscopy in the model’s development of polymeric functional materials formation on inert supports

This work was supported by the RFBR (project No. 18-08-01356 A)

Synthesis and properties of novel polyurethanes based on amino ethers of boric acid for gas separation membranes

© The Royal Society of Chemistry. Herein we present the structural and mechanical properties of polyurethanes synthesized from amino ethers of boric acid for gas separation. The polymers were characterized by light scattering methods, conductivity measurements, thermal gravimetric analysis, Fourier transform infrared spectroscopy, and atomic force microscopy. Additionally, the permeability of ammonia and carbon dioxide, as well as the selectivity for their diffusion and resultant impurity are presented. The results illustrate the steric hindrance, resulting in a branched architecture borate formation, leads to intermolecular complexation which may assist the polymer in ammonia diffusion selectivity

Surface structuring features of polymeric membranes based on chitosan according to atomic force microscopy

С целью выявления механизмов структурообразования модифицированных полимерных мембран на основе хитозана на каждом этапе модификации с помощью метода атомно-силовой микроскопии изучена серия промежуточных образцов.For to reveal surface structuring mechanisms of modified polymeric membranes based on chitosan, a series of intermediate samples was studied using atomic force microscopy at each modification stage.Работа выполнена при финансовой поддержке Российского научного фонда в рамках проекта № 15-19-10057

The surface morphology effect of non-porous polymeric membranes on their gas separation properties

Методом атомно-силовой микроскопии в сочетании с методом Дайнеса-Баррера изучены непористые полиамидные мембраны с различной шероховатостью. Проведен сравнительный анализ полученных результатов. Показана корреляция топографии поверхности изученных мембран с их газоразделительными свойствами.The surface morphology of non-porous polyamide membranes with a different roughness was studied by atomic-force microscopy with combined the Daynes-Barrer method. The comparative analysis of obtained results is carried out. The correlation of the surface topography of studied membranes with their gas separation properties is shown.Работа выполнена при финансовой поддержке Российского научного фонда в рамках проекта № 15-19-10057