In this study, we have conducted a comparative investigation of the interactions of bovine serum albumin (BSA) with a bisquaternary ammonium salt (BQAS) and its monomeric counterpart, dodecyltrimethylammonium bromide (DTAB), by using isothermal titration calorimetry (ITC), fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and molecular docking. ITC measurements showed that BSA has only one binding site for BQAS (N = 0.98 ± 0.28), but multiple binding sites for DTAB (N = 2.38 ± 0.30). The interaction mechanisms of BSA with BQAS and DTAB are similar, as both are enthalpy-driven spontaneous exothermic processes. However, the binding constant of DTAB [(2.38 ± 0.46) × 104 M− 1] is higher than that of BQAS [(1.87 ± 0.25) × 104 M− 1], and the enthalpy change of DTAB (-36.32 ± 5.96 kJ·mol− 1) is also more negative than that of BQAS (-26.84 ± 8.48 kJ·mol− 1). The spectroscopic results from fluorescence and CD measurements indicated that both surfactants bind to the BSA surface, inducing only minor conformational changes in the protein. Molecular docking suggested that DTAB may bind to three distinct negatively charged surface regions on BSA through electrostatic interactions, while BQAS was predicted to bind to only one of these regions. Overall, the two hydrophobic tails of BQAS may enhance the hydrophobicity of the molecule, introduce greater steric hindrance, and possibly reduce the interaction between BQAS and BSA.
The present study investigates temperature-dependent micellization in poly(ethylene oxide, EO)-poly(propylene oxide)-poly(ethylene oxide, PO)-based triblock copolymers (BCPs), also commercially known as Pluronics®, using complementary solution, spectral, and scattering techniques. Here, the solution behaviour of 5
Ginger (Zingiber officinale) rhizome peel is an important industrial waste that embodies a valuable yet underutilized source of total polyphenols having many bioactive properties. However, these compounds are easily degradable and exhibit limited bioavailability, which restricts their effective application. In this present work, pH-responsive composite polysaccharide hydrogel formulations were developed using by ionotropic gelation method for the encapsulation of polyphenols extracted from waste ginger peel. Several physicochemical characterizations of the hydrogels were performed. The maximum encapsulation efficiency among the developed hydrogels was found to be 72
Perfluorohexanone (PFH)-based fire suppression microcapsules face challenges like low loading capacity, poor thermal storage stability, and improper shell thickness, limiting early-stage fire suppression performance. This study investigates adding Span-85 surfactant to optimize microcapsules. Using PFH as the core, Span-85 with varying volume ratios in the PFH phase, ethoxylated trimethylolpropane triacrylate (ETPTA) as the shell, and polyvinyl alcohol (PVA) solution as the focusing phase, microfluidic technology prepares the microcapsules. Wall thickness is measured via optical and scanning electron microscopy; encapsulation efficiency and thermal stability are evaluated by thermogravimetric (TG) analysis and FT-IR. Fire suppression tests on microcapsules and fire suppression patches are conducted. Results show a Span-85:PFH volume ratio of 1:80 yields the optimal wall thickness (17.135 ± 0.82 μm), the highest loading capacity (77.29 ± 2.31
Fluorinated styrene-maleic anhydride copolymer films were designed to regulate surface wettability through hexafluorobutyl acrylate (HFBA). A series of fluorinated SMA-based terpolymers (F-SMA) were synthesized by free-radical solution copolymerization of styrene, maleic anhydride, and HFBA. FT-IR analysis revealed fluorine-related absorption bands in the purified F-SMA samples while confirming the retention of the characteristic anhydride carbonyl bands. The ¹H NMR spectra were used to qualitatively compare the proton environments of the SMA-based polymers, XPS further demonstrated the presence of fluorinated species at the film surface and an increase in the surface F/C atomic ratio across the F-SMA series. The intrinsic viscosity decreased only slightly from 0.39 to 0.37 dL/g across the sample series. GPC analysis of representative SMA, 30 F-SMA, and 50 F-SMA samples further revealed differences in molecular weight and molecular-weight distribution, with apparent weight-average molecular weights (Mw) of 114,561, 113,593, and 91,033 g/mol, respectively. Meanwhile the glass transition temperature decreased with increasing nominal HFBA feed level, while the melt flow rate increased markedly from 5.8 to 42.1 g/10 min. These changes were interpreted by considering the combined influence of molecular-weight variation and structural changes in the fluorinated copolymers. Thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) results showed that the fluorinated copolymers maintained good thermal stability in the main degradation region. Water contact angle measurements revealed a marked increase in surface hydrophobicity, with the maximum value reaching 128.4° for 30 F-SMA. XPS analysis further showed increasing surface fluorine content across the F-SMA series and revealed that the wettability of F-SMA films was governed not only by the surface fluorine content, but also by the interfacial organization of fluorinated side chains. These results provide a structure-property basis for designing SMA-based fluorinated polymer films with tunable wettability and improved processability.
