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1.
Curr Health Sci J ; 50(1): 12-19, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38854421

RESUMO

Postoperative enteroatmospheric fistula (EAF) presents a complex challenge in surgical care, with multifactorial causes and significant implications for patient outcomes and quality of life. This narrative review explores the essential role of nurses in the comprehensive management of EAF, encompassing preoperative, intraoperative, and postoperative care. It emphasizes the importance of wound care management, nutritional support, psychosocial assistance, patient education, collaboration, continuous professional development, and research engagement in optimizing patient outcomes. By addressing these facets, healthcare providers can enhance their understanding and management of EAF, ultimately improving patient care in this intricate surgical complication.

2.
Curr Health Sci J ; 50(1): 125-132, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38846481

RESUMO

Acute biliary pancreatitis (ABP) poses significant challenges in determining the optimal timing and approach for cholecystectomy, particularly in mild, moderately severe, and severe forms. This article reviews the existing literature on cholecystectomy timing and its impact on outcomes in ABP. A systematic literature search yielded 41 relevant articles from PubMed and Scopus databases. In mild ABP, early cholecystectomy within 72 hours of onset is increasingly favoured due to reduced technical difficulty and lower risk of recurrent pancreatitis. Conversely, delayed cholecystectomy, although traditionally practiced, may lead to higher recurrence rates and prolonged hospital stays. For moderate severe ABP, evidence remains limited, but early cholecystectomy appears to decrease hospital stay without increasing perioperative complications. In severe ABP, consensus suggests delaying cholecystectomy until peripancreatic collections resolve, typically 6 to 10 weeks post-onset, to minimize surgical morbidity. The role of endoscopic retrograde cholangiopancreatography (ERCP) alongside cholecystectomy remains contentious, with guidelines recommending its use in specific scenarios such as cholangitis or biliary obstruction. However, routine ERCP in mild ABP lacks robust evidence and may increase complications. Challenges persist regarding the management of residual choledocholithiasis post-ABP, highlighting the need for improved diagnostic criteria and management protocols. Overall, this review underscores the evolving landscape of cholecystectomy timing in ABP and provides insights into current best practices and areas for future research.

3.
Curr Health Sci J ; 49(2): 263-272, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37786622

RESUMO

Diabetes mellitus (DM) and obesity are known to influence postoperative outcomes in surgical patients. This study aimed to analyze the divergence in outcomes between patients with and without DM who underwent ventral hernia repair, while also assessing the additional impact of obesity on postoperative complications, hospitalization, and costs. A prospective, non-interventional, observational study was conducted over five years (2018-2022) at the First Surgical Clinic of Craiova Emergency Clinical Hospital. The study included 216 patients, with 42 (19.44%) having DM, half of whom were also obese. There were no significant differences in age between patients with or without DM. However, diabetes and obesity were more prevalent in female patients. The mean duration of hospitalization was 10.7±8.6 days, with no significant differences observed between patients with or without DM or obesity. Statistical analysis revealed that patients with DM had a higher incidence of seroma formation, wound infection, and hematoma formation compared to patients without DM. However, there were no significant differences in mesh infection, hospitalization days, or costs between the two groups. Similarly, no significant differences were found between obese and non-obese patients in terms of complications, hospitalization days, or costs. In conclusion, this study highlights that DM is associated with an increased risk of specific complications in ventral hernia repair, including seroma formation, wound infection, and hematoma formation. However, the impact of obesity on these outcomes appears to be limited. Individualized preoperative optimization and targeted interventions are necessary to mitigate the risk of complications in patients with DM or obesity.

4.
Chirurgia (Bucur) ; 118(4): 426-434, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37698005

RESUMO

Background: While ventral hernia repair is a frequent surgical intervention, the possibility of complications remains present. The use of drains to mitigate complications is a topic of debate, with conflicting evidence. This study aimed to evaluate the association between drain usage and postoperative complications in ventral hernia repair. Materials and Methods: A single-center prospective study included patients undergoing ventral hernia repair from 2018 to 2022. Patient data and surgical techniques were recorded. Statistical analysis was performed to assess risk factors for drain insertion and complications. Results: Of the 216 patients included, 19.44% had diabetes, and 20% had cancer. Postoperative complications (Clavien Dindo grade IIIB) occurred in 9.3% of cases, resulting in a 3.7% mortality. Decision factors for drain insertion included older age, larger hernia size, bowel resection with anastomosis, emergency setting and the need for adhesiolysis. No differences were found between the two groups regarding seroma and hematoma formation and mesh infection. Patients with drains had a longer hospital stay and higher costs. Conclusion: The decision to use drains in ventral hernia repair was influenced by surgical complexity factors rather than patient characteristics. While drain usage did not correlate with postoperative morbidities, it was associated with longer hospitalization and higher costs. Individualized decision-making is crucial to balance complications and resource utilization in ventral hernia repair.


Assuntos
Drenagem , Hérnia Ventral , Humanos , Estudos Prospectivos , Resultado do Tratamento , Complicações Pós-Operatórias/epidemiologia , Hérnia Ventral/cirurgia
5.
Gels ; 9(8)2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37623079

RESUMO

Magnesium oxide (MgO) was synthesized by three different methods: the sol-gel (SG), microwave-assisted sol-gel (MW), and hydrothermal (HT) methods for comparing the influence of the preparation conditions on the properties of the products. The powders were annealed at 450 °C. The samples were characterized by X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM/HRTEM), selected area electron diffraction (SAED), energy-dispersive X-ray spectroscopy (EDX), BET specific surface area and porosity, photoluminescence, and UV-Vis spectroscopy. The samples consisted mainly of periclase as a crystalline phase, and the MW and HT preparation methods generated particles with higher specific surface areas. The powders had less-defined morphologies and high levels of aggregation. The optical band gaps of the samples were determined from UV DRS, and the photocatalytic activities of the magnesium oxides obtained by the three methods towards the degradation of methyl orange (MO) under UV light irradiation was evaluated.

6.
Gels ; 9(8)2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37623105

RESUMO

Nanostructured oxides (SiO2, TiO2) were synthesized using the sol-gel method and modified with noble metal nanoparticles (Pt, Au) and ruthenium dye to enhance light harvesting and promote the photogeneration of reactive oxygen species, namely singlet oxygen (1O2) and hydroxyl radical (•OH). The resulting nanostructures were embedded in a transparent polyvinyl alcohol (PVA) hydrogel. Morphological and structural characterization of the bare and modified oxides was performed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), UV-Vis spectroscopy, and X-ray photoelectron spectroscopy (XPS). Additionally, electrokinetic potential measurements were conducted. Crystallinity data and elemental analysis of the investigated systems were obtained through X-ray diffraction and X-ray fluorescence analyses, while the chemical state of the elements was determined using XPS. The engineered materials, both as simple powders and embedded in the hydrogel, were evaluated for their ability to generate reactive oxygen species (ROS) under visible and simulated solar light irradiation to establish a correlation with their antibacterial activity against Staphylococcus aureus. The generation of singlet oxygen (1O2) by the samples under visible light exposure can be of significant importance for their potential use in biomedical applications.

7.
J Clin Med ; 12(14)2023 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-37510687

RESUMO

BACKGROUND: Gestational diabetes mellitus (GDM) is a form of diabetes that develops during pregnancy. The incidence of GDM has been on the rise in tandem with the increasing prevalence of obesity worldwide. We focused on the study of what causes premature births and if there are methods to prevent these events that can result in long-term complications. METHODS: This study was a prospective, non-interventional study that lasted for 4 years from December 2018 to December 2022. From the group of women enrolled in the study, we selected and analyzed the characteristics of women who gave birth prematurely. Additionally, we performed a systematic review examining the association between GDM and the frequency of adverse pregnancy outcomes. RESULTS: In total, 78% underwent an emergency caesarean and had polyhydramnios. The results indicate that women who had a preterm delivery had a significantly higher maternal age compared to those who had a term delivery (p < 0.001). Conversely, there was no significant difference in preconception BMI between the two groups (p = 0.12). CONCLUSIONS: In terms of the understanding of GDM and preterm birth, several gaps in our knowledge remain. The association between GDM and preterm birth is likely multifactorial, involving various maternal factors.

8.
Dalton Trans ; 52(30): 10386-10401, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37401566

RESUMO

Two new families of zinc/cobalt/aluminum-based pigments, with a unique composition, were obtained through the polyol method. The hydrolysis process of a mixture of Co(CH3COO)2, Zn(acac)2 and Al(acac)3 (acac- = acetylacetonate ion) in 1,4-butanediol afforded dark blue gels (wPZnxCo1-xAl), in the presence of a supplementary amount of water, and light green powders (PZnxCo1-xAl), respectively, for the water-free procedure (x = 0, 0.2, 0.4). The calcination of the precursors yielded dark green (wZnxCo1-xAl) and blue (ZnxCo1-xAl) products. XRD measurements and Rietveld refinement indicate the co-existence of three spinel phases, in different proportions: ZnxCo1-xAl2O4, Co3O4 and the defect spinel, γ-Al2.67O4. The Raman scattering and XPS spectra are in agreement with the compositions of the samples. The morphology of wZnxCo1-xAl consists of large and irregular spherical particle aggregates (ca. 5-100 mm). Smaller agglomerates (ca. 1-5 mm) with a unique silkworm cocoon-like hierarchical morphology composed of cobalt aluminate cores covered with flake-like alumina shells are formed for ZnxCo1-xAl. TEM and HR-TEM analyses revealed the formation of crystalline, polyhedral particles of 7-43 nm sizes for wZnxCo1-xAl, while for ZnxCo1-xAl, a duplex-type morphology, with small (7-13 nm) and larger (30-40 nm) particles, was found. BET assessment showed that both series of oxides are mesoporous materials, with different pore structures, with the water-free samples exhibiting the largest surface areas due, most likely, to the high percent of aluminum oxide. A chemical mechanism is proposed to highlight the role of the water amount and the nature of the starting compounds in the hydrolysis reaction products and, further, in the morpho-structural features and composition of the resulting spinel oxides. The CIE L*a*b* and C* colorimetric parameters indicate that the pigments are bright, with a moderate degree of luminosity, presenting an outstanding high blueness.

9.
J Clin Med ; 12(11)2023 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-37297940

RESUMO

Littre hernia is a rare type of hernia in which a Meckel diverticulum is found in the hernia sac. Given the rare nature of this disease, little data on demographics and surgical management exists. In this article, we provide a case report of a strangulated inguinal Littre hernia and perform a systematic review of the literature. The PubMed database was searched on 5 March 2022, and all cases of Littre hernia in adults that had English abstracts or full-text were analyzed. Our primary objective was to evaluate the surgical management and outcomes of this particular type of hernia, and our secondary objectives were to assess demographic characteristics, presentation particularities, and recurrence rates. We identified 89 articles with 98 cases, including our own. Results show a high prevalence of complications described intraoperatively, with strangulation being present in up to 38.46% of patients. The laparoscopic approach was utilized in patients with femoral, inguinal, and umbilical hernias. The most commonly performed type of resection was MD resection, followed by bowel resection, while a minority of cases (5.48%) remained unresected. Mesh repair was more frequently performed in patients with MD resection. A mortality rate of 8.7% in patients who underwent bowel resection was found. A relatively high number of reports of ectopic tissue (21.21%), ulceration (12.12%), and tumors (9.09%) were found. The average follow-up was 19.5 ± 10.29 months, with no hernia recurrence. In conclusion, most cases are admitted in an emergency setting, and intestinal obstruction is frequently associated. A minimally invasive approach can be an option even for complicated hernias. MD resection or bowel resection is usually employed, depending on the extent of ischemic lesions. Patients undergoing bowel resection may be prone to worse outcomes.

10.
Materials (Basel) ; 16(12)2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37374445

RESUMO

"Green chemistry" is a simple and easily reproductible method that provides nanoparticles characterized by better stability and good dispersion in an aqueous solution. Nanoparticles can be synthesized by algae, bacteria, fungi, and plant extracts. Ganoderma lucidum is a commonly used medicinal mushroom with distinctive biological properties, such as antibacterial, antifungal, antioxidant, anti-inflammatory, anticancer, etc. In this study, aqueous mycelial extracts of Ganoderma lucidum were used to reduce AgNO3 to form silver nanoparticles (AgNPs). The biosynthesized nanoparticles were characterized by UV-visible spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analysis. The maximum UV absorption was obtained at 420 nm, which represents the specific surface plasmon resonance band for biosynthesized silver nanoparticles. SEM images showed particles as predominantly spherical, while FTIR spectroscopic studies illustrated the presence of functional groups that can support the reducing of ion Ag+ to Ag(0). XRD peaks ratified the presence of AgNPs. The antimicrobial effectiveness of synthesized nanoparticles was tested against Gram-positive and Gram-negative bacterial and yeasts strains. The silver nanoparticles were effective against pathogens, inhibiting their proliferation, and thus reducing the risk to the environment and to public health.

11.
Gels ; 9(6)2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37367173

RESUMO

The present work reports the synthesis of efficient Ti-Au/zeolite Y photocatalysts by different processing of aluminosilicate gel and studies the effect of titania content on the structural, morphological, textural, and optical properties of the materials. The best characteristics of zeolite Y were obtained by aging the synthesis gel in static conditions and mixing the precursors under magnetic stirring. Titania (5, 10, 20%) and gold (1%) species were incorporated in zeolite Y support by the post-synthesis method. The samples were characterized by X-ray diffraction, N2-physisorption, SEM, Raman, UV-Vis and photoluminescence spectroscopy, XPS, H2-TPR, and CO2-TPD. The photocatalyst with the lowest TiO2 loading shows only metallic Au on the outermost surface layer, while a higher content favors the formation of additional species such as: cluster type Au, Au1+, and Au3+. A high TiO2 content contributes to increasing the lifetime of photogenerated charge careers, and the adsorption capacity of the pollutant. Therefore, an increase in the photocatalytic performances (evaluated in degradation of amoxicillin in water under UV and visible light) was evidenced with the titania content. The effect is more significant in visible light due to the surface plasmon resonance (SPR) effect of gold interacting with the supported titania.

12.
Gels ; 9(4)2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-37102879

RESUMO

Using the microwave-assisted sol-gel method, Zn- and Cu-doped TiO2 nanoparticles with an anatase crystalline structure were prepared. Titanium (IV) butoxide was used as a TiO2 precursor, with parental alcohol as a solvent and ammonia water as a catalyst. Based on the TG/DTA results, the powders were thermally treated at 500 °C. XRD and XRF revealed the presence of a single-phase anatase and dopants in the thermally treated nanoparticles. The surface of the nanoparticles and the oxidation states of the elements were studied using XPS, which confirmed the presence of Ti, O, Zn, and Cu. The photocatalytic activity of the doped TiO2 nanopowders was tested for the degradation of methyl-orange (MO) dye. The results indicate that Cu doping increases the photoactivity of TiO2 in the visible-light range by narrowing the band-gap energy.

13.
Antioxidants (Basel) ; 12(3)2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36978939

RESUMO

ZnSe, ZnSe-TiO2 microspheres and nanostructured TiO2 obtained by hydrothermal and sol-gel methods were tested against Staphylococcus aureus ATCC 25923 and Micrococcus lysodeikticus ATCC 4698 before and after lysozyme (Lys) loading. Morphological characterization of inorganic matrices and hybrid organic-inorganic complexes were performed by microscopy techniques (SEM, AFM and Dark Field Hyperspectral Microscopy). Light absorption properties of ZnSe, ZnSe-TiO2 and TiO2 powders were assessed by UV-visible spectroscopy and their ability to generate reactive oxygen species (•OH and O2•-) under visible light irradiation was investigated. Antibacterial activity of ZnSe, ZnSe-TiO2, TiO2, Lys/ZnSe, Lys/ZnSe-TiO2 and Lys/TiO2 samples under exposure to visible light irradiation (λ > 420 nm) was tested against Staphylococcus aureus and Micrococcus lysodeikticus and correlated with ROS photogeneration.

14.
Curr Health Sci J ; 49(4): 524-529, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38559840

RESUMO

Inguinal hernia surgery is a constantly evolving field, with ongoing research efforts aimed at enhancing surgical techniques and outcomes for patients. This retrospective study conducted between 2015 and 2020 in the First Surgical Clinic of Craiova Emergency Clinical Hospital focused on the occurrence and characteristics of postoperative pain following inguinal hernia repair using the tension-free Lichtenstein procedure. A total of 178 patients were included in the study, with 16.85% reporting postoperative pain. The average pain intensity was 6.4 on a scale of 1 to 10. Patients described the pain as numbness, burning sensation, stinging, pressure, and tingling sensations. Notably, 50% of patients reported pain related to weather changes. While the study explored potential relationships between patient demographics, hernia type, and postoperative pain, no statistically significant associations were found. Approximately 20% of patients with postoperative pain reported adverse effects on their work, and 10% used analgesics for pain management. This study highlights the multifaceted nature of postoperative pain following inguinal hernia repair, emphasizing the need for further research to identify individual risk factors and adherence to international guidelines for hernia management. The findings also underscore the importance of effective pain management strategies to improve patient comfort and quality of life post-surgery.

15.
Gels ; 8(12)2022 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-36547335

RESUMO

In this paper, we conducted a fundamental study concerning the effect of thermal treatment on the structure and morphology of 2 mol% vanadium doped ZnO nanopowders obtained by microwave assisted sol-gel method (MW). The samples were analyzed by DTA, FTIR, XRD, SEM, and UV-Vis spectroscopy. The DTA results showed that above 500 °C, there was no mass loss in the TG curves, and ZnO crystallization occurred. The XRD patterns of the thermally treated powders at 500 °C and 650 °C showed the crystallization of ZnO (zincite) belonging to the wurtzite-type structure. It was found that in the 650 °C thermally treated powder, aside from ZnO, traces of Zn3(VO4)2 existed. FTIR spectra of the annealed samples confirmed the formation of the ZnO crystalline phase and V-O bands. The micrographs revealed that the temperature influenced the morphology. The increase in the annealing temperature led to the grain growth. The SEM images of the MW powder thermally treated at 650 °C showed two types of grains: hexagonal grains and cylindrical nanorods. UV-Vis spectra showed that the absorption band also increased with the increasing temperature of thermal treatment. The MW sample annealed at 650 °C had the highest absorption in ultraviolet domain.

16.
Gels ; 8(11)2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36354625

RESUMO

The aim of the present study was the development of Nb-doped ITO thin films for carbon monoxide (CO) sensing applications. The detection of CO is imperious because of its high toxicity, with long-term exposure having a negative impact on human health. Using a feasible sol-gel method, the doped ITO thin films were prepared at room temperature and deposited onto various substrates (Si, SiO2/glass, and glass). The structural, morphological, and optical characterization was performed by the following techniques: X-ray diffractometry (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and UV/Vis/NIR spectroscopic ellipsometry (SE). The analysis revealed a crystalline structure and a low surface roughness of the doped ITO-based thin films. XTEM analysis (cross-sectional transmission electron microscopy) showed that the film has crystallites of the order of 5-10 nm and relatively large pores (around 3-5 nm in diameter). A transmittance value of 80% in the visible region and an optical band-gap energy of around 3.7 eV were found for dip-coated ITO/Nb films on SiO2/glass and glass supports. The EDX measurements proved the presence of Nb in the ITO film in a molar ratio of 3.7%, close to the intended one (4%). Gas testing measurements were carried out on the ITO undoped and doped thin films deposited on glass substrate. The presence of Nb in the ITO matrix increases the electrical signal and the sensitivity to CO detection, leading to the highest response for 2000 ppm CO concentration at working temperature of 300 °C.

17.
Gels ; 8(10)2022 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-36286174

RESUMO

For environmental applications, nanosized TiO2-based materials are known as the most important photocatalyst and are intensively studied for their advantages such as their higher activity, lower price, and chemical and photoresist properties. Zn or Cu doped TiO2 nanoparticles with anatase crystalline structure were synthesized by sol-gel process. Titanium (IV) butoxide was used as a TiO2 precursor, with parental alcohol as a solvent, and a hydrolysing agent (ammonia-containing water) was added to obtain a solution with pH 10. The gels were characterized by TG/DTA analysis, SEM, and XPS. Based on TG/DTA results, the temperature of 500 °C was chosen for processing the powders in air. The structure of the samples thermally treated at 500 °C was analysed by XRD and the patterns show crystallization in a single phase of TiO2 (anatase). The surface of the samples and the oxidation states was investigated by XPS, confirming the presence of Ti, O, Zn and Cu. The antibacterial activity of the nanoparticle powder samples was verified using the gram-positive bacterium Staphylococcus aureus. The photocatalytic efficiency of the doped TiO2 nanopowders for degradation of methyl orange (MO) is here examined in order to evaluate the potential applications of these materials for environmental remediation.

18.
Nanomaterials (Basel) ; 12(18)2022 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-36144974

RESUMO

This work presents the synthesis of nanostructured TiO2 modified with noble metal nanoparticles (Au, Ag) and lysozyme and coated on titanium foil. Moreover, the specific structural and functional properties of the resulting inorganic and hybrid materials were explored. The purpose of this study was to identify the key parameters for developing engineered coatings on titanium foil appropriate for efficient dental implants with intrinsic antibacterial activity. TiO2 nanoparticles obtained using the sol-gel method were deposited on Ti foil and modified with Au/Ag nanoparticles. Morphological and structural investigations (scanning electron and atomic force microscopies, X-ray diffraction, photoluminescence, and UV-Vis spectroscopies) were carried out for the characterization of the resulting inorganic coatings. In order to modify their antibacterial activity, which is essential for safe dental implants, the following aspects were investigated: (a) singlet oxygen (1O2) generation by inorganic coatings exposed to visible light irradiation; (b) the antibacterial behavior emphasized by titania-based coatings deposited on titanium foil (TiO2/Ti foil; Au-TiO2/Ti foil, Ag-TiO2/Ti foil); (c) the lysozyme bioactivity on the microbial substrate (Micrococcus lysodeicticus) after its adsorption on inorganic surfaces (Lys/TiO2/Ti foil; Lys/Au-TiO2/Ti foil, Lys/Ag-TiO2/Ti foil); (d) the enzymatic activity of the above-mentioned hybrids materials for the hydrolysis reaction of a synthetic organic substrate usually used for monitoring the lysozyme biocatalytic activity, namely, 4-Methylumbelliferyl ß-D-N,N',N″-triacetylchitotrioside [4-MU-ß- (GlcNAc)3]. This was evaluated by identifying the presence of a fluorescent reaction product, 7-hydroxy-4-metyl coumarin (4-methylumbelliferone).

19.
Nanomaterials (Basel) ; 12(18)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36145032

RESUMO

Undoped and Zn-doped ITO (ITO:Zn) multifunctional thin films were successfully synthesized using the sol-gel and dipping method on three different types of substrates (glass, SiO2/glass, and Si). The effect of Zn doping on the optoelectronic, microstructural, and gas-sensing properties of the films was investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), spectroscopic ellipsometry (SE), Raman spectroscopy, Hall effect measurements (HE), and gas testing. The results showed that the optical constants, the transmission, and the carrier numbers were correlated with the substrate type and with the microstructure and the thickness of the films. The Raman study showed the formation of ITO films and the incorporation of Zn in the doped film (ITO:Zn), which was confirmed by EDX analysis. The potential use of the multifunctional sol-gel ITO and ITO:Zn thin films was proven for TCO applications or gas-sensing experiments toward CO2. The Nyquist plots and equivalent circuit for fitting the experimental data were provided. The best electrical response of the sensor in CO2 atmosphere was found at 150 °C, with activation energy of around 0.31 eV.

20.
Int J Mol Sci ; 23(18)2022 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-36142243

RESUMO

The present work aims to show how the main properties of poly(methacrylic acid) (PMAA) hydrogels can be engineered by means of several silicon-based fillers (Laponite XLS/XLG, montmorillonite (Mt), pyrogenic silica (PS)) employed at 10 wt% concentration based on MAA. Various techniques (FT-IR, XRD, TGA, SEM, TEM, DLS, rheological measurements, UV-VIS) were used to comparatively study the effect of these fillers, in correlation with their characteristics, upon the structure and swelling, viscoelastic, and water decontamination properties of (nano)composite hydrogels. The experiments demonstrated that the nanocomposite hydrogel morphology was dictated by the way the filler particles dispersed in water. The equilibrium swelling degree (SDe) depended on both the pH of the environment and the filler nature. At pH 1.2, a slight crosslinking effect of the fillers was evidenced, increasing in the order Mt < Laponite < PS. At pH > pKaMAA (pH 5.4; 7.4; 9.5), the Laponite/Mt-containing hydrogels displayed a higher SDe as compared to the neat one, while at pH 7.4/9.5 the PS-filled hydrogels surprisingly displayed the highest SDe. Rheological measurements on as-prepared hydrogels showed that the filler addition improved the mechanical properties. After equilibrium swelling at pH 5.4, G' and G" depended on the filler, the Laponite-reinforced hydrogels proving to be the strongest. The (nano)composite hydrogels synthesized displayed filler-dependent absorption properties of two cationic dyes used as model water pollutants, Laponite XLS-reinforced hydrogel demonstrating both the highest absorption rate and absorption capacity. Besides wastewater purification, the (nano)composite hydrogels described here may also find applications in the pharmaceutical field as devices for the controlled release of drugs.


Assuntos
Nanocompostos , Poluentes da Água , Bentonita , Corantes , Preparações de Ação Retardada , Hidrogéis/química , Metacrilatos , Nanocompostos/química , Nanogéis , Silicatos , Silício , Dióxido de Silício , Espectroscopia de Infravermelho com Transformada de Fourier , Água
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