Design of Friction, Morphology, Wetting, and Protein Affinity by Cellulose Blend Thin Film Composition

Abstract

Cellulose derivate phase separation in thin films was applied to generate patterned films with distinct surface morphology. Patterned polymer thin films are utilized in electronics, optics, and biotechnology but films based on bio-polymers are scarce. Film formation, roughness, wetting, and patterning are often investigated when it comes to characterization of the films. Frictional properties, on the other hand, have not been studied extensively. We extend the fundamental understanding of spin coated complex cellulose blend films via revealing their surface friction using Friction Force Microscopy (FFM). Two cellulose derivatives were transformed into two-phase blend films with one phase comprising trimethyl silyl cellulose (TMSC) regenerated to cellulose with hydroxyl groups exposed to the film surface. Adjusting the volume fraction of the spin coating solution resulted in variation of the surface fraction with the other, hydroxypropylcellulose stearate (HPCE) phase. The film morphology confirmed lateral and vertical separation and was translated into effective surface fraction. Phase separation as well as regeneration contributed to the surface morphology resulting in roughness variation of the blend films from 1.1 to 19.8 nm depending on the film composition. Friction analysis was successfully established, and then revealed that the friction coefficient of the films could be tuned and the blend films exhibited lowered friction force coefficient compared to the single-component films. Protein affinity of the films was investigated with bovine serum albumin (BSA) and depended mainly on the surface free energy (SFE) while no direct correlation with roughness or friction was found. BSA adsorption on film formed with 1:1 spinning solution volume ratio was an outlier and exhibited unexpected minimum in adsorption.

Classification of bananas during ripening using peel roughness analysis—An application of atomic force microscopy to food process

“…Similar to roughness results, this parameter decreased significantly with advancing banana fruit ripening and, thus, confirmed the visual quality assessment in Section 3.1, too. A similar trend was reported by Czibula et al (2019) at design of friction, morphology, wetting, and protein affinity by cellulose blend thin‐film composition.…”

“…Also, as many researchers have reported, besides the vertical roughness, the lateral roughness fluctuations are important. So, the lateral correlation length of roughness was calculated based on the method by Czibula et al (2019).…”

Comparison of Protein-Repellent Behavior of Linear versus Dendrimer-Structured Surface-Immobilized Polymers

“…In contrast to the results presented here, a correlation could be established between the substrate’s SFE (or components thereof) and the amounts of adsorbed protein in other studies. Decreasing adsorption of bovine serum albumin on cellulose-based surface modifications with increasing SFE was detected by Czibula et al Similarly, Michiardi et al observed a linear correlation between the polar component of the SFE and the amount of adsorbed HSA, which was not found in this study either.…”

Anisotropic Optical and Frictional Properties of Langmuir–Blodgett Film Consisting of Uniaxially‐Aligned Rod‐Shaped Cellulose Nanocrystals

“…There have been efforts made to characterize the anisotropic properties of CNCs, but some degree of fluctuations and deviations from theoretical models have been observed, mainly due to the surrounding matrices and unknown arrangements of CNCs in sublayers. [ 35,37,40,45 ]…”