25 documents found, page 1 of 3
Diazo-coupled porous organic polymers as efficient catalysts for metal-free Hen...
Machado, Tiago F.; Valente, Artur J. M.; Serra, M. Elisa Silva; Murtinho, DinaOwing to linkage and building block diversity, Porous Organic Polymers (POPs) are versatile materials with high potential in organic catalysis. Herein, nitrogen-rich POPs bearing –OH phenolic groups were synthesized via the diazo-coupling reactions between phloroglucinol and benzidine (PgBd-POP), and between 1,3,5-tris(4-aminophenyl) triazine and 4,4’-[1,1′ -biphenyl]-4,4′ -diylbis(diazene-2,1-diyl))diphenol (T...
Micro-/Nanofibrillated Cellulose-Based Coating Formulations: A Solution for Imp...
Sharma, Mohit; Aguado, Roberto; Murtinho, Dina; Valente, Artur J. M.; Ferreira, Paulo J. T.The use of micro-/nanofibrillated celluloses (M/NFCs) is often considered for the enhancement of paper properties, while it is still challenging to use them in lower weight gain coatings. This work explores how they might be used on the paper surface to improve the printing quality. In this regard, M/NFCs were produced using different pre-treatment methods, including mechanical (m-MFC), enzymatic (e-MFC), TEMPO...
β-Ketoenamine Covalent Organic Frameworks-Effects of Functionalization on Pollu...
Machado, Tiago F.; Santos, Filipa A.; Pereira, Rui F. P.; de Zea Bermudez, Verónica; Valente, Artur J. M.; Serra, M. Elisa Silva; Murtinho, DinaWater pollution due to global economic activity is one of the greatest environmental concerns, and many efforts are currently being made toward developing materials capable of selectively and efficiently removing pollutants and contaminants. A series of β-ketoenamine covalent organic frameworks (COFs) have been synthesized, by reacting 1,3,5-triformylphloroglucinol (TFP) with different C2-functionalized and non...
β-ketoenamine covalent organic frameworks—effects of functionalization on pollu...
Machado, Tiago F.; Santos, Filipa A.; Pereira, Rui Francisco Gonçalves Pinto Fernandes; de Zea Bermudez, Verónica; Valente, Artur J. M.Water pollution due to global economic activity is one of the greatest environmental concerns, and many efforts are currently being made toward developing materials capable of selectively and efficiently removing pollutants and contaminants. A series of β-ketoenamine covalent organic frameworks (COFs) have been synthesized, by reacting 1,3,5-triformylphloroglucinol (TFP) with different C2-functionalized and non...
Novel approach on the synthesis of starch betainate by transesterification
Sharma, Mohit; Aguado, Roberto; Murtinho, Dina; Valente, Artur J. M.; Ferreira, Paulo J. T.Transesterification of starch with methyl betainate was studied for the first time, both in aprotic media and in solid state, and both under alkaline and acidic conditions. Betaine hydrochloride was first esterified in methanol, attaining a conversion of 86%. Starch was then converted into starch betainate in either N,N-dimethylformamide or dimethyl sulfoxide, and using sulfuric acid as catalyst or pre-activati...
Synergetic effect of cationic starch (ether/ester) and Pluronics for improving ...
Sharma, Mohit; Aguado, Roberto; Murtinho, Dina; Valente, Artur J. M.; Ferreira, Paulo J. T.Improving the printability of paper is still a relevant challenge, despite the fast development of digital communications. While it is well-known that cationic starches enhance ink density, their commercial paper-grade forms are limited to ethers with low degree of substitution. This work addresses the underexplored potential of highly substituted cationic starch for paper coating and its combination with tri-b...
Poly(β-cyclodextrin)-Activated Carbon Gel Composites for Removal of Pesticides ...
Utzeri, Gianluca; Veríssimo, Luís; Murtinho, Dina; Pais, Alberto; Perrin, F. Xavier; Ziarelli, Fabio; Iordache, Tanta-Verona; Sarbu, AndreiPesticides are widely used in agriculture to increase and protect crop production. A substantial percentage of the active substances applied is retained in the soil or flows into water courses, constituting a very relevant environmental problem. There are several methods for the removal of pesticides from soils and water; however, their efficiency is still a challenge. An alternative to current methods relies o...
Covalent Organic Frameworks: Synthesis, Properties and Applications-An Overview
Machado, Tiago F.; Serra, M. Elisa Silva; Murtinho, Dina; Valente, Artur J. M.; Naushad, MuCovalent Organic Frameworks (COFs) are an exciting new class of microporous polymers with unprecedented properties in organic material chemistry. They are generally built from rigid, geometrically defined organic building blocks resulting in robust, covalently bonded crystalline networks that extend in two or three dimensions. By strategically combining monomers with specific structures and properties, synthesi...
Mini-review: Synthetic methods for the production of cationic sugar-based surfa...
Jesus, Carolina F.; Alves, Andreia A. S.; Fiuza, Sónia M.; Murtinho, Dina; Antunes, Filipe E.Surfactants are ubiquitously used and are currently indispensable in our daily life. However, the increased surfactant production has given rise to some environmental and health concerns making it imperative to look for new sustainable and viable alternatives. Sugar based surfactants, sourced from renewable sources are an excellent candidate to solve this problem. This class of surfactants has been developed in...
Synergetic effect of cationic starch (ether/ester) and Pluronics for improving ...
Sharma, Mohit; Aguado, Roberto; Murtinho, Dina; Valente, Artur J. M.; Ferreira, Paulo J.Improving the printability of paper is still a relevant challenge, despite the fast development of digital communications. While it is well-known that cationic starches enhance ink density, their commercial paper-grade forms are limited to ethers with low degree of substitution. This work addresses the underexplored potential of highly substituted cationic starch for paper coating and its combination with tribl...