scholarly journals Modification of Electrospun Regenerate Cellulose Nanofiber Membrane via Atom Transfer Radical Polymerization (ATRP) Approach as Advanced Carrier for Laccase Immobilization

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 182
Author(s):  
Shuo Zeng ◽  
Jinwei Shi ◽  
Anchao Feng ◽  
Zhao Wang

This study aimed to modify an electrospun regenerated cellulose (RC) nanofiber membrane by surface grafting 2-(dimethylamino) ethyl methacrylate (DMAEMA) as a monomer via atom transfer radical polymerization (ATRP), as well as investigate the effects of ATRP conditions (i.e., initiation and polymerization) on enzyme immobilization. Various characterizations including XPS, FTIR spectra, and SEM images of nanofiber membranes before and after monomer grafting verified that poly (DMAEMA) chains/brushes were successfully grafted onto the RC nanofiber membrane. The effect of different ATRP conditions on laccase immobilization was investigated, and the results indicated that the optimal initiation and monomer grafting times were 1 and 2 h, respectively. The highest immobilization amount was obtained from the RC-Br-1h-poly (DMAEMA)-2h membrane (95.04 ± 4.35 mg), which increased by approximately 3.3 times compared to the initial RC membrane (28.57 ± 3.95 mg). All the results suggested that the optimization of initiation and polymerization conditions is a key factor that affects the enzyme immobilization amount, and the surface modification of the RC membrane by ATRP is a promising approach to develop an advanced enzyme carrier with a high enzyme loading capacity.

2017 ◽  
Vol 48 (1) ◽  
pp. 25-37
Author(s):  
Quan Feng ◽  
Xin Li ◽  
Dingsheng Wu ◽  
Suo Liu ◽  
Mao Ye ◽  
...  

AOPAN nanofibers were prepared by electrospinning and amidoxime modification, subsequently, HEMA was used as the monomers for surface grafting via atom transfer radical polymerization, followed by coordination with Cu(II) ions, thereafter, the nanofibers AOPAN-poly(HEMA)-Cu(II) were explored as the novel support for laccase immobilization. Scanning electron microscopy was used to visualize the morphology of the nanofibers, and Fourier transform infrared spectroscopy was used to provide information on the surface chemistry of nanofibers. At the same time, the optimization of immobilization conditions and the relative properties of the immobilized laccase were also studied in this paper. The study showed the largest amount of immobilized laccase while the reaction time of atom transfer radical polymerization was 4 h. The immobilized laccase showed a better stability resistance to temperature and pH change, and the initial activity of immobilized laccase retained (60.3 ± 3.1)%, that of the free laccase retained only (21.3 ± 2.1)% when stored at 4℃ for 24 days. Immobilized laccase maintained its initial activity after 10 repeated batches of 64.5%.


2012 ◽  
Vol 32 (2) ◽  
Author(s):  
Khezrollah Khezri ◽  
Vahid Haddadi-Asl ◽  
Hossein Roghani-Mamaqani ◽  
Mehdi Salami-Kalajahi

Abstract Well-defined poly(styrene-co-butyl acrylate) nanocomposite latexes were synthesized via reverse atom transfer radical polymerization (RATRP) in miniemulsion. Successful RATRP was carried out by using a hydrophobic ligand of 4,4’-dinonyl-2,2’-bipyridine (dNbpy) and a cationic surfactant of cetyltrimethylammonium bromide (CTAB). Dynamic light scattering (DLS) results show that droplets and particles with sizes in the range of about 170 nm were formed. Overall, conversion and molecular weight evaluation were performed by using gravimetry and size exclusion chromatography (SEC), respectively. Increasing nanoclay loading resulted in an increase in the conversion and molecular weight of the nanocomposites. However, polydispersity index (PDI) values increased by adding nanoclay content. Thermal stability of all the nanocomposites improved in comparison with the neat copolymer, according to the thermogravimetric analysis (TGA) results. Differential scanning calorimetry (DSC) results showed that the glass transition temperature (Tg) increased by increasing nanoclay content. Scanning electron microscopy (SEM) images of the nanocomposite with 1 wt% of nanoclay showed a monodisperse distribution of spherical particles, with sizes in the range of approximately 170 nm, as confirmed by the DLS data. Similarly, transmission electron microscopy (TEM) images show that clay layers are delaminated and well dispersed in the matrix of nanocomposite with 1 wt% clay content.


2008 ◽  
Vol 311 (1-2) ◽  
pp. 225-234 ◽  
Author(s):  
Nripen Singh ◽  
Zhen Chen ◽  
Namrata Tomer ◽  
S. Ranil Wickramasinghe ◽  
Neil Soice ◽  
...  

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