9 documents found, page 1 of 1
Effects of the modification of bacterial cellulose as a template for the in sit...
Shim, Euijin; Silva, C.; Cavaco-Paulo, Artur; Kim, Hye RimIn this study, we investigated the effects of the modification of bacterial cellulose used as a template on the in situ polymerization of catechol by laccase. The bacterial cellulose was modified by sulfonation and the entrapment of carboxymethyl cellulose. The catechol polymerization was optimized at a pH of 5.5, catechol concentration of 50mM, and synthesis time of 24h. After the in situ polymerization, condu...
Improvement of bacterial cellulose nonwoven fabrics by physical entrapment of l...
Song, J.; Cavaco-Paulo, Artur; Silva, C.; Kim, Hye RimThe present study aimed to improve the properties of bacterial cellulose nonwoven fabrics by physical entrapment of lauryl gallate oligomers. The lauryl gallate oligomerization process was conducted by laccase-mediated oligomerization. Lauryl gallate was chemically confirmed by matrix-assisted laser desorption/ionization with time-of-flight analyses. The oligomerization conditions were controlled considering th...
Carboxymethyl Cellulose (CMC) as a template for laccase-assisted oxidation of a...
Shim, Euijin; Noro, Jennifer Martins; Cavaco-Paulo, Artur; Kim, Hye Rim; Silva, C.Polyaniline (PANi) is a conducting polymer which has been subject of intensive research on the exploitation of new products and applications. The main aim of the work is the development of a conductive bacterial cellulose (BC)-based material by enzymatic-assisted polymerization of aniline. For this, we study the role of carboxymethyl cellulose (CMC) as a template for the in situ polymerization of aniline. Bacte...
Functionalization of bacterial cellulose nonwoven by poly(fluorophenol) to impr...
Song, J.; Silva, C.; Cavaco-Paulo, Artur; Kim, Hye RimThe present study aims to improve the hydrophobicity and durability of bacterial cellulose (BC) nonwoven by functionalization with poly(fluorophenol). To this end, laccase was first entrapped onto BC and then used to polymerize the fluorophenol {4-[4-(trifluoromethyl) phenoxy] phenol} in-situ. The polymerization of fluorophenol by laccase was confirmed through 1H NMR and MALDI-TOF analyses. The effect of poly(f...
Conductive bacterial cellulose by in situ laccase polymerization of aniline
Shim, Euijin; Su, Jing; Noro, Jennifer Martins; Teixeira, Marta Albertina; Cavaco-Paulo, Artur; Silva, Carla; Kim, Hye RimConductive and colored bacterial cellulose (BC) was developed by entrapment of polyaniline (PANi) onto dry BC membranes. The polyaniline was produced by in situ green polymerization of aniline by Myceliophthora thermophila laccase at pH = 4, 25°C, in the presence of a mediator, 1-hydroxybenzotriazol (HBT), using two different reactors, a water bath (WB) and an ultrasonic bath (US). MALDI-TOF and 1H NMR characte...
Effect of additives on the in situ laccase-catalyzed polymerization of aniline ...
Shim, Euijin; Noro, Jennifer Martins; Cavaco-Paulo, Artur; Silva, Carla; Kim, Hye RimLaccase-mediated systems are a green route to accelerate the oxidation of aniline and obtain polyaniline with conductive properties. The synthesis of green polyaniline (emeraldinesalt)washereinimprovedbytheinclusionofadditiveslikesodiumbis(2–ethyl hexyl) sulfosuccinate (AOT) and potassium hexacyanoferrate (II) (KHCF) in the medium. The aniline polymerization was confirmed by the detection of the absorption band ...
Conductive cotton by in situ laccase-polymerization of aniline
Su, Jing; Shim, Euijin; Noro, Jennifer Martins; Fu, Jiajia; Wang, Qiang; Kim, Hye Rim; Silva, Carla Manuela Pereira Marinho; Cavaco-Paulo, ArturConductive cotton fabrics were obtained via in situ aniline polymerization by laccase from Myceliophthora thermophila under mild reaction conditions without the addition of strong proton acids. The reactions were conducted using two types of reactors, namely a water bath (WB) and an ultrasonic bath (US), and the role of a mediator, 1-hydroxybenzotriazol (HBT), on the laccase-assisted polymerization of aniline w...
Bio-coloration of bacterial cellulose assisted by immobilized laccase
Song, J.; Su, Jing; Noro, Jennifer; Cavaco-Paulo, Artur; Silva, Carla; Kim, Hye RimIn this work a process for the bio-coloration of bacterial cellulose (BC) membranes was developed. Laccase from Myceliophthora thermophila was immobilized onto BC membranes and retained up to 88% of residual activity after immobilization. Four compounds belonging to the flavonoids family were chosen to test the in situ polymerase activity of immobilized laccase. All the flavonoids were successfully polymerized ...
Ultrasound-assisted swelling of bacterial cellulose
Song, J.; Su, Jing; Loureiro, Ana; Sá, M.; Cavaco-Paulo, Artur; Kim, Hye Rim; Silva, CarlaBacterial cellulose (BC) was obtained by static cultivation using commercial BC gel from scoby. BC membranes (oven dried and freeze-dried) were swelled with 8% NaOH, in absence and in presence of ultrasound (US), for 30, 60 and 90 min. The influence of swelling conditions on both physico-chemical properties and molecules entrapment was evaluated. Considering the highest levels of entrapment, an optimum swelling...