Polymers and Plastics, Fuel Technology, Colloid and Surface Chemistry, Waste Management and Disposal
128
Scopus Publications
Scopus Publications
Evaluation of the Influence of Antifoam Formulations on Asphaltene Aggregates Using AFM and SEM-EDS Mariana Teixeira Mendes, Andressa Oliveira dos Santos, Rafael Farias Perez, Osvaldo Karnitz Junior, Claudia Regina Elias Mansur Journal of Applied Polymer Science, 2026 Asphaltenes, naturally occurring surfactants in crude oil play a pivotal role in stabilizing oily foams during primary oil processing. Accordingly, understanding how antifoam formulations influence asphaltene aggregation is essential. This study investigates the effect of polydimethylsiloxane (PDMS) with varying molar masses on asphaltene organization using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). SEM provided morphological characterization of the asphaltene aggregates, showing that PDMS with different molar masses alters both the size and structure of these clusters. AFM offered complementary nanoscale insights, revealing how PDMS impacts the interfacial behavior of asphaltenes. The findings demonstrate that PDMS molar mass significantly affects the dispersion and aggregation of asphaltenes, highlighting its potential for enhancing additive performance in petroleum processing. Overall, this study advances the understanding of PDMS–asphaltene interactions and supports the development of more effective solutions for oil and gas separation in primary processing in the oil industry.
Optimization of cationic functionalized nanoparticles for brain targeting: in vivo evaluation Kaique Alves Brayner Pereira, Melissa Chamon Alves Premazzi, Vinicius de Lima Gonçalves, Bruno Jorge Duque da Silva, Carolina Baeta Salvador Várady, Mariana Mello e Souza, Rodrigo Muller, Renata Chagas Bastos, Claudia Regina Elias Mansur, Patricia Barbosa Jurgilas Biochemical and Biophysical Research Communications, 2025
Performance of Carboxymethyl Starch and Chitosan as Green Scale Inhibitors for Calcite and Gypsum Precipitation Hugo N. S. Barros, Kaio A. B. Pereira, Matheus V. Oliveira, Luiz Antônio B. Rocha, Luiz C. M. Palermo, Claudia R. E. Mansur Chemistryselect, 2025 Scale formation represents a significant problem in oil industry and results in a cost increase to maintain operations. The main reasons for this include the reduction in the fluid flow, the obstruction of pipelines, as well as accidents in more severe cases. However, many commercial chemistry inhibitors of inorganic scale are phosphate‐base, which has high toxicity to the environment. Therefore, biopolymers‐based scale inhibitors are alternatives and have been gaining ground in these applications, as they are abundant, low cost and environmentally friendly. In this study, the products derived from chitosan and starch were carboxymethylated, characterized, and evaluated for their inhibition of calcium sulphate precipitation by static efficiency tests and calcium carbonate by dynamic efficiency tests. The products were characterized by FTIR, H‐NMR, and TGA, whereas the crystals were analyzed using optical and scanning electron microscopy. The performance tests for the additives were conducted under simulated reservoir conditions, with temperatures of 70 and 80 °C and brine models. The standard calcium compatibility test was performed at 70 °C. The results showed that the chemical modification was successful and that the products demonstrated excellent compatibility with calcium standards. The performance tests showed high static efficiency, up to 95% for calcium sulphate, and the additives were approved in the dynamic protocol, CMCh and CMSt, with MIC values around 20–40 ppm and 10 ppm, respectively. The micrographs revealed morphological modifications that corroborated the performance results.
Assessment of Asphaltene and Maltene Interfacial Interactions with Antifoam Additives: A Rheological Approach Mariana T. Mendes, Andressa O. dos Santos, Rafael F. Perez, Osvaldo Karnitz Junior, Claudia R. E. Mansur ACS Omega, 2025 Polydimethylsiloxane (PDMS)-based oil antifoams are extensively employed, but still, their impact on oil remains inconclusive due to the intricate nature and diverse composition of the oil. So far, the literature declares asphaltenes as the main contributors to foam stabilization followed by resins, along with short-chain carboxylic acids, solids, and even naphthenic acids. The present work aims to study the influence of antifoam formulations containing silicones of different molar masses on the oil/air interface, as well as evaluate its influence on the fractions separately, that is, on asphaltenes, on the model solution/air interface, and also on resins, examining the maltene/air interface. Hence, the interfacial rheology technique utilizing the Double Wall Ring (DWR) accessory was employed to assess the viscoelastic behavior of oil and its constituents (asphaltenes and maltenes) in the presence of antifoam products. This approach aims to gain insight into how these products interact with the oil-air interface and the various fractions of the oil. The findings from the DWR accessory align with the results of the foam formation tests, indicating that the products demonstrating superior efficacy in reducing the initial foam height also played a role in decreasing the interfacial elastic modulus of the respective systems.
Application of Cassia Gum in Enhanced Oil Recovery Raíssa Takenaka Rodrigues Carvalho, Neimar Paulo de Freitas, Agatha Densy dos Santos Francisco, Luiz Carlos Palermo, Claudia Regina Elias Mansur ACS Polymers Au, 2025 The objective of this study was to develop an innovative biopolymer, cassia gum, for enhanced oil recovery (EOR) applications. The gum was extracted from the seeds of Cassia grandis, a native Brazilian tree, using a novel method that achieved an average yield of 24.4 ± 1.7 wt %. Structural characterization identified cassia gum as a nonionic galactomannan with an average molar mass (Mw) of 8.07 × 105 ± 1.44 × 105 g/mol and an organic matter content of 80.32%. A cassia gum-saline solution at 3,000 mg/L, prepared using injection water containing 29,711 mg/L of total dissolved solids, exhibited shear-thinning rheological behavior and viscoelastic properties, with a viscosity of 21.38 cP at 60 °C, closely matching crude oil viscosity. Viscoelastic testing revealed a transition from viscous to elastic behavior, enhancing EOR efficiency by improving sweep and microscopic oil displacement. Contact angle tests with API 25 oil demonstrated that cassia gum could alter carbonate rock wettability from oil-wet to intermediate-wet. Coreflooding experiments under reservoir conditions showed that cassia gum-saline fluid achieved an additional oil recovery of 13.6% OOIP, following 38.5% OOIP recovery during waterflooding. These results establish cassia gum as a promising biopolymer for EOR applications.
Extraction, characterization, and evaluation of galactomannan from Barbatimão Verdadeiro as a potential additive for enhanced oil recovery fluids Mariana S. Aquino, Juliana P. Senna, Claudia R. E. Mansur International Journal of Polymer Analysis and Characterization, 2025 Polymers play a crucial role in enhanced oil recovery (EOR) by increasing the viscosity of injection fluids and enhancing oil displacement. The widely used polymer, partially hydrolyzed polyacrylamide (HPAM), faces performance degradation in high-salinity and high-temperature environments. This study explores galactomannan from <i>Stryphnodendron polyphyllum</i> seeds as an alternative viscosifying agent for EOR fluids. An extraction process for galactomannan from Barbatimão Verdadeiro seeds was developed, yielding 23.3% m/m. The biopolymer was characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA), and size exclusion chromatography (SEC). Rheological behavior was tested in brines of different salinities, and injectivity/filterability tests were performed following API RP 63:1990 standards. The galactomannan obtained from <i>Stryphnodendron polyphyllum</i> exhibited a mannose-to-galactose ratio of 1.32. Rheological analysis showed pseudoplastic behavior, with viscosities of 38 cP in brine solutions at 7.37 s<sup>−1</sup> and 60 °C. Filterability tests demonstrated satisfactory injectivity with factors of 1.09 (8 µm) and 0.67 (1.2 µm). Compared to HPAM, galactomannan exhibited superior viscosity retention in high-salinity conditions, where HPAM dropped to 6 cP. The galactomannan extracted from <i>Stryphnodendron polyphyllum</i> seeds is a promising biopolymer for EOR applications, offering superior performance under harsh conditions compared to traditional HPAM. Its resilience to high salinity and temperature makes it a viable alternative for pre-salt and offshore fields, contributing to more sustainable and efficient oil recovery.
Nanosystems with potential application as carriers for skin depigmenting actives Natalia Ruben Castro, Cristal Dos Santos C Pinto, Elisabete P Dos Santos, Claudia Regina E Mansur Nanotechnology, 2024 Hyperpigmentation is a skin disorder characterized by excessive production of melanin in the skin and includes dyschromias such as post-inflammatory hyperchromias, lentigens, melasma and chloasma. Topical products containing depigmenting agents offer a less aggressive treatment option for hyperpigmentation compared to methods like chemical peels and laser sessions. However, some of these agents can cause side effects such as redness and skin irritation. Encapsulating these actives in nanosystems shows promise in mitigating these effects and improving product safety and efficacy. In addition, nanocarriers have the ability to penetrate the skin, potentially allowing for targeted delivery of actives to the affected areas. The most commonly investigated nanosystems are nanoemulsions, vesicular nanosystems and nanoparticles, in which different materials can be used to generate different compositions in order to improve the properties of these nanocarriers. Nanocarriers have already been widely explored, but it is necessary to understand the evolution of these technologies when applied to the treatment of skin hyperchromias. Therefore, this literature review aims to present the state of the art over the last 15 years on the use of nanosystems as a potential strategy for encapsulating depigmenting actives for potential application in cosmetic products for skin hyperchromia. By providing a comprehensive overview of the latest research findings and technological advances, this article can contribute to improving the care and quality of life of people affected by this skin condition.
Production and Evaluation of Hydroxypropyl Starch as a Viscosifying Agent for Enhanced Oil Recovery Kelly Lúcia Nazareth Pinho de Aguiar, Karen de Sá Gomes, Matheus Ferreira da Silva Licht, Luiz Carlos Magalhães Palermo, Claudia Regina Elias Mansur Chemistryselect, 2024 In this study, starch was obtained from rice wastes and the maximum extraction yield was 90.95 %. Chemical modification reactions were carried out by hydroxypropylation to obtain a modified starch extract, named 005A, soluble in synthetic injection brine. Extract 005A had a modified starch concentration of 1.24 %, with a pseudoplastic rheological profile and viscosities of 325.54 cP and 121.03 cP at temperatures of 25 and 60 °C, respectively. The application of extract 005A was evaluated by injectivity/filterability tests, which indicated a good filtration rate and viscosity loss of 3.81 % when passing the fluid through the filtering membrane. Stability tests indicated that the 005A extract had a viscosity loss of 21.35 %, at the temperature of 60 °C, after 60 days. The application of this extract enabled additional mineral oil recovery of 12.19 % in simulated core flooding tests. Therefore, the extract of hydroxypropyl starch is a promising viscosifying agent for Enhanced Oil Recovery (EOR) fluids.
Microemulsified systems based on passion fruit oil as potential green corrosion inhibitors for carbon steel P110 in saline medium saturated with CO2 21st International Corrosion Congress Icc Intercorr Wco 2021, 2021
Nanosystems in photoprotection Cristal dos Santos Cerqueira Coutinho, Elisabete P. dos Santos, Claudia R. E. Mansur Journal of Nanoscience and Nanotechnology, 2015
Efficiency analysis of nanoemulsions systems containing silicone polyether as demulsifying and antifoaming agents for petroleum Nanoscale Science and Engineering Forum 2013 Core Programming Area at the 2013 Aiche Annual Meeting Global Challenges for Engineering A Sustainable Future, 2014
Development and evaluation of nanostructured formulations containing 8-methoxalen Pharmaceutical Discovery Development and Manufacturing Forum 2013 Core Programming Area at the 2013 Aiche Annual Meeting Global Challenges for Engineering A Sustainable Future, 2013
Removal of oil from oily waters by chitosan microspheres: Batch studies Environmental Division 2013 Core Programming Area at the 2013 Aiche Annual Meeting Global Challenges for Engineering A Sustainable Future, 2013
A study of asphaltene-resin interactions Luiz C. C. Marques, Juliana O. Pereira, André D. Bueno, Valdo S. Marques, Elizabete F. Lucas, Claudia R. E. Mansur, André L. C. Machado, Gaspar González Journal of the Brazilian Chemical Society, 2012
