Impact of Point Mutations on the Structure and Thermal Stability of Ribonuclease T1 in Aqueous Solution Probed by Fourier Transform Infrared Spectroscopy

Biochemistry ◽  
1994 ◽  
Vol 33 (35) ◽  
pp. 10725-10730 ◽  
Author(s):  
Heinz Fabian ◽  
Christian Schultz ◽  
Jan Backmann ◽  
Ulrich Hahn ◽  
Wolfram Saenger ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Aqueous Solution ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Point Mutations ◽  
Fourier Transform Infrared ◽  
Ribonuclease T1 ◽  
Thermal Stability Of

Production and characterization of boron nitride-doped nanofiber mats created through electrospinning

2016 ◽  
Vol 47 (6) ◽  
pp. 993-1005 ◽  
Author(s):  
Yasemin Cakmak ◽  
M Fatih Canbolat ◽  
Enes Cakmak ◽  
Mehmet Dayik
Keyword(s):  
Thermal Stability ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Thermogravimetric Analysis ◽  
Boron Nitride ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Electrospinning Method ◽  
The Fourier Transform ◽  
Nanofiber Mats

The aim of this study was to produce advanced nanofiber mats by adding boron nitride to poly (ɛ-caprolactone) polymer using an electrospinning method and to characterize the resultant structures. Pure poly (ɛ-caprolactone) nanofiber mats and boron nitride-doped nanofiber mats prepared at different concentrations were compared. The morphological structures of the nanofiber mats were examined under a scanning electron microscope, spectroscopic analyses were conducted using Fourier transform infrared spectroscopy, and thermal stability was analyzed using a thermogravimetric analysis method. Successful electrospinning of boron nitride-doped nanofibers at lower voltages was achieved. The thermogravimetric analysis test found that the thermal stability of boron nitride-doped nanofiber mats is higher than that of pure nanofibers, which suggests that the produced composite material could be preferable in applications involving insulation and high temperature. On the other hand, the Fourier transform infrared spectroscopy results indicated that no chemical reaction occurred between boron nitride and the poly (ɛ-caprolactone) nanofibers.

Structure of Styrene/Acrylic Acid Copolymer in Aqueous Solution Determined by Fourier Transform Infrared Spectroscopy

1987 ◽  
Vol 41 (4) ◽  
pp. 590-596 ◽  
Author(s):  
Marek W. Urban ◽  
Jack L. Koenig ◽  
L. B. Shih ◽  
James R. Allaway
Keyword(s):  
Aqueous Solution ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Acrylic Acid ◽  
Benzyl Alcohol ◽  
Fourier Transform Infrared Spectroscopy ◽  
Fourier Transform Infrared ◽  
Conformational Structure ◽  
Acid Copolymer ◽  
Acrylic Acid Copolymer

A random styrene/acrylic acid copolymer has been examined by Fourier transform infrared spectroscopy with the use of the attenuated total reflectance (ATR) technique, in a study of the conformational structure in aqueous solution. The presence of a base in the aqueous solution leads to ionization of the acrylic acid segments and to conformational changes. The ionization is demonstrated by the appearance of asymmetric and symmetric C-O stretching bands of the COO− ion at 1547 and 1407 cm−1. Our results show that the water molecules are coordinated to the COO− ion through the positively charged cations. The acrylic segments of the copolymer are exposed to the aqueous solvent, whereas styrene is surrounded by acrylates. The molecular interactions of the copolymer in the two-phase water and benzyl alcohol system are determined. In the benzyl alcohol phase, the copolymer forms a coil-type structure, with the acrylic acid segments exposed to the aqueous phase. With time, the cations diffuse into the benzyl alcohol phase and cause ionization of the acrylic acid units, resulting in formation of the COO− ions.

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