Article
Polymer Science
Jingru Liu, Bingkun Lu, Rui Xiao
Summary: The comparative study on the annealing-induced high impact toughness of linear and grafted polypropylene random copolymer (PPR and MPP) was conducted. It was found that PPR displayed higher flexural modulus and impact strength, as well as lower elongation at break than MPP. After thermal annealing treatment, the crystallinity and impact strength of PPR were significantly increased compared to those of MPP.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2023)
Article
Polymer Science
Zhiyao Zhang, Xueqin Gao
Summary: This study investigates the impact of adding short glass fibers and ethylene propylene diene monomer on the printability and mechanical properties of polypropylene random copolymer in FFF. The results show that the modified polymer has good printability and mechanical properties.
Article
Polymer Science
Stan F. S. P. Looijmans, Hamid Ahmadi, Patrick D. Anderson, Lambert C. A. van Breemen
Summary: Despite the maturity of the technology, processing of fiber-reinforced thermoplastic materials remains challenging. This study investigated the effect of adhesion enhancement on material properties and found that the addition of a compatibilizer agent has minimal effect on modulus and yield stress, but significantly reduces strain-at-break. In-situ X-ray characterization methods revealed that the role of phase composition and morphology is more pronounced in deformation and failure mechanisms than the increased adhesion. These findings suggest a new route towards tougher fiber-reinforced composites with reduced complexity.
Article
Polymer Science
Jingru Liu, Dexing Jiang, Zihan Li
Summary: This study introduces ABS into iPP and further annealing treatment to improve the impact toughness of iPP. The introduction of ABS and annealing treatment have a synergistic effect on toughening iPP.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2022)
Article
Polymer Science
Se Bin Jin, Lam Tan Hao, Sung Yeon Hwang, Dongyeop X. Oh, Jun Mo Koo, Hyeonyeol Jeon, Sung Bae Park, Jeyoung Park
Summary: Nylon/chitosan nanowhisker (CSW) masterbatch with a high concentration (30 wt%) was prepared by blending nylon 6,10 and CSW through solvent casting, followed by the preparation of nylon/CSW nanocomposites via melt blending with a large quantity of nylon 6,10. Stirring time in the presence of formic acid was found to affect the structure of CSW and the physical properties of the composite. The nanocomposite stirred for 1.5 h exhibited superior mechanical properties, indicating the suitability of the stirring condition.
Article
Engineering, Multidisciplinary
Shunjie Zhao, Rongyan Hu, Lianghai Zhu, Mingzhao Li, Feng Chen, Qiang Wu, Yonggang Shangguan, Qiang Zheng
Summary: The PPR/EPR/SiO2 nanocomposites prepared through toughening strategy showed excellent low-temperature impact resistance, with the brittleductile transition behavior being adjusted by silica and rubber contents. Dynamic rheological results indicated a strong shape relaxation ability in the nanocomposites.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Polymer Science
Mahmoud Embabi, Mu Sung Kweon, Ya Xian Wang, Tzu-Pin Lin, Carlos R. Lopez-Barron, Patrick C. Lee
Summary: This study investigates the effect of ionic content on the foaming behavior of linear PP ionomers and finds that ionomers with higher ionic content exhibit better foam properties.
Article
Materials Science, Composites
Marta Zaccone, Irene Kociolek, Alberto Frache, Costanzo Bellini, Vittorio Di Cocco, Marco Monti
Summary: This paper evaluates the abrasion resistance of a carbon fiber composite filled with layered-silicate clay nanoparticles. The study investigates the dispersion and performance of the clay-epoxy nanocomposite, and determines the optimal content for fiber composite production. The nanocomposite mixture is prepared by dispersing clay nanoparticles in the epoxy monomer, followed by vacuum infusion to produce the fiber reinforced composite. The presence of nanoclay reduces weight loss and damage on the impacted surface.
POLYMER COMPOSITES
(2023)
Article
Chemistry, Physical
Eva Skoura, Peter Bohac, Martin Barlog, Helena Palkova, Andreas Mautner, Larysa Bugyna, Helena Bujdakova, Juraj Bujdak
Summary: The poly(caprolactone) was modified with a thin nanocomposite layer consisting of organoclay and photoactive dye, PhB. Electron microscopy, water contact angle measurements, X-ray diffraction, and various spectroscopies were used to characterize the surface properties and composition of the nanocomposite layer. The films exhibited photoactive and antimicrobial properties.
APPLIED CLAY SCIENCE
(2023)
Article
Chemistry, Physical
Milad Maleki, Hamed Mirzadeh, Massoud Emamy
Summary: The synergistic effects of copper addition and hot extrusion process were studied on the modification of microstructure and enhancement of mechanical properties of a common in situ hypereutectic Mg-Si metal-matrix composite. The results showed that copper addition at a microalloying level of 0.5 wt% effectively modified the microstructure and improved the mechanical properties of the as-cast material. However, higher copper additions led to poor tensile properties due to the deleterious effects of eutectics. The hot extrusion process resulted in fragmentation and dispersion of intermetallics, as well as intense grain refinement by dynamic recrystallization, leading to enhanced mechanical properties of the composites.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Multidisciplinary
Huajie Mao, Hao Li, Wei Guo, Min Wu, Fankun Zeng
Summary: Microcellular polypropylene (PP) materials, toughened by olefin block copolymer (OBC), have wide applications in various industries. The addition of OBC improves the crystallinity, rheological properties, and cell structure of foamed PP materials, resulting in increased toughness. A simulation model predicts the material performance, showing that the optimal toughness is achieved by adding a certain amount of OBC and void fraction.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Construction & Building Technology
Hui Guo, Linzhi Jiang, Junlin Tao, Yu Chen, Zhiqin Zheng, Bin Jia
Summary: The hybrid combination of steel and polypropylene fibers can enhance the toughness of high-strength concrete. Steel fibers have a greater impact on the toughness of HSC, while polypropylene fibers have a smaller effect. The optimal hybrid combination can improve the bending and tensile toughness of the concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Engineering, Multidisciplinary
Raziyeh S. Mohammadi, Ali M. Zolali, Seyed H. Tabatabaei, Abdellah Ajji
Summary: Premature failure in polymer blends mainly occurs at interfaces between immiscible polymers, but this phenomenon has been exploited to develop a peelable film with a wide peelable seal-temperature window. By adding organoclay and PB-1, the peel strength of the PE/PB-1 blends is improved and the thickness of the PB-1 phase is significantly reduced, leading to enhanced interfacial cracking and consistent peel performance.
COMPOSITES PART B-ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Li Li, Chenyu Yan, Ning Zhang, Muhammad Usman Farooqi, Shilang Xu, Ahmed Farouk Deifalla
Summary: Geopolymer concrete can effectively reduce the negative environmental impacts of cement manufacturing. In this study, the effect of polypropylene fibers (PP fiber) with different properties on fracture toughness was evaluated. Experimental groups of PP fiber geopolymers were tested, and the results showed that the reinforcing index influenced the fracture toughness, with an initial increase and subsequent decrease. Low water-binder ratios generally led to higher fracture properties. PP fiber showed better toughness enhancement and economic benefits compared to other fibers.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Nanoscience & Nanotechnology
Seon Ju Lee, Moon Young Choi, Lee Ku Kwac, Hong Gun Kim, Jin-Hae Chang
Summary: In this study, organoclays with different alkyl chain lengths were dispersed in poly(amic acid) (PAA) and polyimide (PI) hybrid films were prepared. The effects of organoclay content on the thermal, morphological, and optical properties of the hybrid films were investigated.
REVIEWS ON ADVANCED MATERIALS SCIENCE
(2023)
Article
Polymer Science
Rodrigo T. Umemura, Maria Isabel Felisberti
Summary: In this study, PHB and TEC were blended to investigate the effects of TEC as a plasticizer on the properties of PHB. Increasing the mass fraction of TEC led to gradual changes in mechanical, thermal, and morphological properties of PHB, with TEC acting as an efficient plasticizer. The presence of TEC reduced the glass transition and melting temperatures of PHB, expanded the processing window of temperature, and influenced the crystallization kinetics and morphology of PHB.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Chemistry, Multidisciplinary
Jacqueline L. Barbosa, Giovanni B. Perin, Maria Isabel Felisberti
Summary: This study investigated the effects of PLAP as a plasticizer in PHBV formulations on the material properties, including processability, miscibility, microstructure, as well as thermal, morphological, and mechanical properties. The results showed that an increase in PLAP mass fraction led to changes in the composition of the amorphous phases, an increase in crystalline lamellae and interlamellar layer thickness, and a decrease in melting and glass transition temperatures as well as PHBV stiffness. The distribution of PLAP in the rigid and mobile amorphous phases and the microstructure of the crystalline phase of PHBV in the formulations significantly influenced the mechanical properties.
Article
Multidisciplinary Sciences
Fariza Abrao, Thayna Souza Silva, Claudia L. Moura, Sergio Ricardo Ambrosio, Rodrigo Cassio Sola Veneziani, Raphael E. F. de Paiva, Jairo Kenupp Bastos, Carlos Henrique Gomes Martins
Summary: The study evaluated the antibacterial and antivirulence activity of oleoresins from different copaifera species and isolated compounds against periodontitis-causing bacteria. These compounds showed promising activity in inhibiting biofilm formation and eradication, as well as in cysteine protease and leucotoxin inhibition, suggesting their potential as novel sources for combating periodontal pathogens.
SCIENTIFIC REPORTS
(2021)
Article
Pharmacology & Pharmacy
Tuany Zambroti Candido, Raphael Enoque Ferraz de Paiva, Mariana Cecchetto Figueiredo, Lilian de Oliveira Coser, Silmara Cristina Lazarini Frajacomo, Camilla Abbehausen, Izilda Aparecida Cardinalli, Wilton Rogerio Lustri, Joao Ernesto Carvalho, Ana Lucia Tasca Gois Ruiz, Pedro Paulo Corbi, Carmen Silvia Passos Lima
Summary: This study evaluated the effects of a silver(I) complex with nimesulide (AgNMS) on skin squamous cell carcinoma (SSCC) treatment, incorporated in a sustained release device based on bacterial cellulose membrane. The AgNMS complex showed antiproliferative activity and induced multicaspase activation on FaDu cells. The AgNMS@BCM reduced tumor size without inducing toxicity in a SSCC mouse model.
Article
Parasitology
Igor Andrade Santos, Anna Karla dos Santos Pereira, Marco Guevara-Vega, Raphael Enoque Ferraz de Paiva, Robinson Sabino-Silva, Fernando R. G. Bergamini, Pedro P. Corbi, Ana Carolina G. Jardim
Summary: Most patients with Chikungunya virus (CHIKV) infection suffer from chronic manifestations in joints, which greatly affect their quality of life. In this study, the antiviral activity of rimantadine hydrochloride (rtdH), its platinum complex (Pt-rtd), and a precursor cis-[PtCl2(dmso)(2)] against CHIKV infection in vitro was evaluated. The results showed that rtdH exhibited significant antiviral activity in all stages of CHIKV replication, while Pt-rtd complex displayed the strongest effect, reducing up to 100% of CHIKV infection. Molecular docking analysis and infrared spectroscopy data suggested that Pt-rtd interacts with CHIKV glycoproteins and inhibits viral entry. The study highlights the potential of rtdH and Pt-rtd as anti-CHIKV drugs.
Article
Polymer Science
Daniela de Morais Zanata, Maria Isabel Felisberti
Summary: A series of thermo- and pH-responsive triblock copolymers were synthesized and their phase behavior was comprehensively studied. The copolymers exhibited self-assembly into different aggregates depending on pH and temperature conditions.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Biochemistry & Molecular Biology
Fernando R. G. Bergamini, Julia H. B. Nunes, Carlos Marrote Manzano, Marcos Alberto de Carvalho, Marcos Antonio Ribeiro, Ana Lucia Tasca Gois Ruiz, Joao Ernesto de Carvalho, Wilton Rogerio Lustri, Raphael Enoque Ferraz de Paiva, Marcelo Cecconi Portes, Ana Maria da Costa Ferreira, Pedro Paulo Corbi
Summary: In this study, polynuclear CuII coordination compounds with nalidixic acid derivatives were synthesized and investigated for their structural features, antibacterial and antitumor activities, as well as their interactions with bovine serum albumin (BSA) and DNA plasmid (pGEX-4 T1).
JOURNAL OF INORGANIC BIOCHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Raphael E. F. de Paiva, Wyatt E. Johnson, Anil K. Gorle, Susan J. Berners-Price, Nicholas P. Farrell
Summary: This study investigates the interaction between non-hydrogen-donor ligand-based octahedral cobalt(III) and ruthenium(II) complexes and glycosaminoglycans (GAGs). The results showed that [Co(bpy)3]3+ binds to highly sulfated synthetic pentasaccharide Fondaparinux (FPX) without major disturbances, while [Ru(bpy)3]2+ inhibits the enzymatic cleavage of FPX by heparinase II. This suggests a direct inhibition mechanism of heparinase II by the ruthenium compound, which is unrelated to metalloshielding.
JOURNAL OF INORGANIC BIOCHEMISTRY
(2022)
Article
Biochemistry & Molecular Biology
Giovanni Bortoloni Perin, Maria Isabel Felisberti
Summary: This study elucidates the mechanism of Candida antacticalipase B (CALB)-catalyzed polycondensation of glycerol and sebacic acid in polar solvents and identifies acyl migration as the key esterification reaction. The study also reveals the significant influence of solvent's hydrogen bonding accepting ability and polymer-solvent interaction on the catalysis rate and polymer chain growth.
Review
Chemistry, Inorganic & Nuclear
Carlos M. Manzano, Douglas H. Nakahata, Raphael E. F. de Paiva
Summary: This article provides an overview of recent studies on metal complexes in the treatment of skin cancers, including in vitro, in vivo, and clinical data. The structure-activity relationships of lead coordination complexes for skin cancer chemotherapy are discussed based on a careful analysis of the literature and databases. The article also highlights recent advances in understanding skin composition, photodynamic therapies, immunological responses, and molecular mechanisms of skin cancers.
COORDINATION CHEMISTRY REVIEWS
(2022)
Article
Polymer Science
Victor Ferrao, Giovanni Bortoloni Perin, Maria Isabel Felisberti
Summary: In this work, PHBV composites were prepared using TEC as a biodegradable plasticizer and SBF as reinforcement via melting extrusion. TEC reduced the viscosity and thermomechanical degradation of PHBV, while SBF acted as a nucleation agent for PHBV crystallization and enhanced the tensile properties of the matrix. TEC and SBF had antagonistic effects on the properties of the composites, providing opportunities for property tuning by varying the composition.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Polymer Science
Rafael Natal Lima de Menezes, Maria Isabel Felisberti
Summary: Crosslinked aggregates have shown potential as mimics of cells, organelles, and nanoreactors. They are stable against hydrolytic degradation and can be modulated in swelling and molecular transport by pH.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Alex Gibney, Raphael E. F. de Paiva, Vandana Singh, Robert Fox, Damien Thompson, Joseph Hennessy, Creina Slator, Christine J. McKenzie, Pegah Johansson, Vickie McKee, Fredrik Westerlund, Andrew Kellett
Summary: In this study, a Cu-catalysed azide-alkyne cycloaddition reaction produced a 1,2,3-triazole linker that was used to create Cu-binding artificial metallo-nucleases (AMNs). A bioactive C-3-symmetric ligand called TC-Thio was developed using biologically inert reaction partners. The ligand formed Cu-II and Cu-I complexes through Cu coordination, and showed potent DNA binding and cleaving abilities. Mechanistic studies revealed that DNA recognition occurred at the minor groove, leading to oxidative damage through a pathway dependent on superoxide and peroxide. Single molecule imaging demonstrated that the complex caused DNA damage recognized by base excision repair enzymes, comparable to the clinical drug temozolomide.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Inorganic & Nuclear
Julia Helena Bormio Nunes, Douglas Hideki Nakahata, Pedro Paulo Corbi, Raphael Enoque Ferraz de Paiva
Summary: Sulfonamides are revolutionary drugs for the treatment and management of bacterial infections, with additional activities against tumors, fungi, and viruses. Silver sulfadiazine, a widely used sulfonamide, has been applied topically for the prevention and treatment of burn patients' infections. However, there is ongoing debate regarding the true efficacy of silver sulfadiazine as a topical treatment for burn wounds compared to other dressings loaded or not with silver-containing agents.
COORDINATION CHEMISTRY REVIEWS
(2023)
Article
Biochemistry & Molecular Biology
Daniel Oliveira Silva Martins, Rafael Aparecido Carvalho Souza, Marjorie Caroline Liberato Cavalcanti Freire, Nathalya Cristina de Moraes Roso Mesquita, Igor Andrade Santos, Debora Moraes de Oliveira, Nilson Nicolau Junior, Raphael Enoque Ferraz de Paiva, Mark Harris, Carolina Goncalves Oliveira, Glaucius Oliva, Ana Carolina Gomes Jardim
Summary: This study evaluated the antiviral activity and mechanism of action of a cobalt(III) thiosemicarbazone complex named [Co-III(L-1)(2)]Cl against chikungunya virus (CHIKV). The complex showed strong inhibitory activity against CHIKV replication with no toxicity in healthy cells. It exerted a post-entry effect on viral replication by interacting with CHIKV non-structural protein 4 (nsP4), and molecular docking analysis suggested potential interactions through hydrogen bonds, hydrophobic and electrostatic interactions.
JOURNAL OF BIOLOGICAL INORGANIC CHEMISTRY
(2023)
