Shorter Chain Length Research Articles

Naturally russeted and wound russeted skins of mango (cv. ‘Apple’) show no differences in anatomy, chemical composition or gene expression

The mango cultivar ‘Apple’ is commercially important in Kenya but highly susceptible to russeting. Russeting refers to an area of fruit skin where the primary (epidermal) surface has been replaced by a secondary (peridermal) surface. The objective was to establish histologies, gene expressions and chemical compositions of a natural periderm, a wound-induced periderm and of cuticles of an un-russeted skin. Fluorescence microscopy revealed a suberized phellem in natural and wound-induced periderms. Wound-induced periderms had more cell layers and a higher mass than natural periderms. Compared with cuticles, periderms showed decreased expressions of cuticle-related genes (MiSHN1, MiGPAT6, MiCUS1, MiCER1, MiWCB11) and increased expressions of periderm-related genes (MiMYB93, MiNAC058, MiCYP86A1, MiCYP86B1, MiGPAT5, MiABCG20). Natural periderms and wound-induced periderms contained cutin and suberin monomers (C16-C28), including carboxylic, dicarboxylic, and ω-hydroxy acids and primary alcohols. Cuticles of the primary skin contained cutin monomers of similar chemistry but shorter chain lengths (C16-C22). The wax composition in natural and wound-induced periderms was similar to that in cuticles. Lignin monomers in natural and wound-induced periderms contained p-hydroxyphenyl, guaiacyl and syringyl units, but only traces of these occurred in cuticles. In ‘Apple’ mango, the histologies, gene expressions and compositions of natural and wound-induced periderms are largely the same.

A Crystal Structure of an Oligoproline Hexamer with a Zig‐zag Arrangement

AbstractOligoprolines adopt the well‐defined polyproline II (PPII) helical conformation, even at a short chain length of six residues. These rigid peptides are versatile molecular rulers and scaffolds, yet there has been great difficulty in obtaining single crystals for X‐ray crystal structure analysis to probe their conformation in the solid state. Here, we report a crystal structure of an oligoproline hexamer bearing an N‐terminal terephthalic acid moiety. Comparison with that of a previously obtained crystal structure of a closely related hexaproline revealed influence of the terminal functional groups and the solvent on the crystal packing.

The Ether’s Chain Length Effect in Electrolyte for Hard carbon towards Efficient Sodium Storage at Low Temperature

The synergy between ether-based electrolytes (EBEs) and hard carbon (HC) in sodium-ion batteries (SIBs) enhances Coulombic efficiency, durability, and rate capability. Despite these advantages, the intricate relationship of how the molecular structure of ether solvents modifies electrolyte properties and, subsequently, sodium storage performance remains inadequately explored, especially for low-temperature applications, limiting the advancement of EBEs. Our study investigates ethylene glycol ether-based electrolytes with varying chain lengths to understand their influence on reaction kinetics and sodium storage. Notably, HC electrodes paired with NaPF6/ethylene glycol dimethyl ether exhibit superior performance, achieving 247.5 mAh g-1 after 2000 cycles at 1.0Ag-1. Even at -20 °C, these cells exhibit impressive endurance, retaining capacities of 257.5 mAh g-1 in half cells and 75.5 mAh g-1 in full cells at 0.1Ag-1 after 100 cycles, considering the entire mass of active material. Our thorough analysis indicates that the ether solvent with shorter chain length, distinguished by its low solvation-free energy and accelerated ionic kinetics, promotes rapid de-solvation and the formation of an inorganic-rich interface. Through this study, we illuminate the pivotal influence of solvent chain length on sodium storage in hard carbon, contributing to foundational insights towards the design of sophisticated electrolytes for SIBs.

Plasma triacylglycerol length and saturation level mark healthy aging groups in humans.

Complex lipids, essential components in biological processes, exhibit conserved age-related changes that alter membrane properties and cellular functions and are implicated as biomarkers and contributors to longevity and age-related diseases. While physical activity alleviates age-related comorbidities and physical impairments, comprehensive exploration of the underlying biological mechanisms, particularly at the level of complex lipids, remains limited. However, clinical studies suggest that physical activity may counteract these age-related lipidomic changes, presenting a promising avenue for intervention. We performed lipidomic profiling of plasma from an extensively characterized cohort of young and aged individuals. Annotating 1446 unique lipid species across 24 lipid classes, we found the most prominent difference in older adults was an accumulation of triacylglycerols (TGs), with lower physical activity levels associated with higher TG levels in plasma and reduced physical functionality. Remarkably, lipid species in the TG class did not accumulate uniformly. Rather, our study unveiled a negative correlation between higher physical activity levels and TGs with shorter chain lengths and more double bonds in this demographic. Overall, our research highlights that plasma TG length and saturation level can help mark healthy aging groups in humans. These findings deepen our understanding of how aging affects complex lipids and the influence of physical activity on this process.

Meta-Connected Oligo-Azobenzenes Outperform Their Para Counterparts.

Systems with multiple photoswitchable units in one molecule have attracted considerable attention in the past years as they are useful for a broad variety of possible applications. Especially, linked azobenzenes sharing one benzene ring are of high interest since their direct linkage introduces an additional photoswitchable unit at only small increase in molecular weight. In this spirit, linear oligo-azobenzenes had been synthesized, though their photochemical properties have only been investigated for short chain lengths. In this study, we use (time-dependent) density functional methodology for the evaluation of the excitations of meta- and para-connected oligo-azobenzenes to predict their switching ability. It becomes apparent, that the meta connection pattern enables each azobenzene subunit to act as an individual switchable unit, whereas they are strongly coupled and loose their individuality in para connection. Therefore, meta-oligo-azobenzenes are ideal candidates for future studies of azobenzene-based functional polymers, while para-oligo-azobenzenes are not.

Deciphering Biosynthesis Mechanism and Solution Properties of Cyclic Amylopectin.

A novel cyclic amylopectin (CA) was synthesized from waxy corn starch (WCS) using Bacillus stearothermophilus branching enzyme (BstBE), providing insights into its biosynthesis mechanism and solution properties. During the first 4 h, BstBE partially cyclized WCS, producing 68.20% CA with a significantly reduced molecular weight (MW), from 8.98 × 10⁶ to 3.19 × 10⁴ g/mol and a lower polymer dispersity index (PDI), decreasing from 1.97 to 1.12. This resulted in a uniform CA structure with shorter chain lengths, particularly increasing DP 3-13, especially DP 7-9. Over the subsequent 4-12 h, the PDI slightly increased to 1.18 as the CA content decreased to 50.48%, with an increase in small ring structures (DP 6-12) of CA, suggesting both ring-opening and ring-downsizing due to continued enzyme catalysis. These results propose a two-stage reaction model: initial cyclization followed bybranching and secondary cyclization. CA exhibited excellent solution properties, with BE-4 and BE-12 samples demonstrating high solubility (≥65 g/100 mL), low viscosity (<0.01 Pa·s), and over 90% light transmittance after 14 days at 4 °C, highlighting its broad application potential.

The Association Between the Structure of the Fatty Chain in Amides and Their Lubricating Performance in Acrylonitrile‐Butadiene‐Styrene (ABS) Resins

ABSTRACTThe exploitation of efficient lubricants for ABS resins is widely recognized as beneficial for industrial production. Fatty diamides are typically applied as the lubricants for ABS resins; however, the connection between fatty chain structures and the lubricating properties is still vague. In this work, a range of ethylenediamine‐based amide lubricants (EDA‐Cn) with different fatty chain structures were successfully prepared and chemical structures were characterized in detail by the Fourier transform infrared spectrometer and proton nuclear magnetic resonance. The rheological test results suggested that the complex viscosity and relaxation time were positively associated with the fatty chain lengths of EDA‐Cn. The dynamic mechanical analysis results confirmed that EDA‐Cn exhibited excellent compatibility with ABS resins. The lubricating effect of EDA‐Cn decreased with increasing fatty chain lengths, which was manifested by a higher glass transition temperature, and lower elongation at break of ABS resins. In comparison to EDA‐C22, the complex viscosity (angular frequency = 0.1 rad/s) and glass transition temperature of EDA‐C10 have decreased by 24.9% and 3.9%, respectively. The molecular dynamics simulations revealed the intrinsic mechanism of lubricant‐substrate interaction. The EDA‐Cn containing short fatty chain lengths reduced the interaction energy with the matrix, thereby promoting the diffusive movement of the chain segments, and resulted in the increase in the mean square displacement and improved flow properties. These findings provided sufficient theoretical basis for the rational design and preparation of lubricants for ABS resins.

Candida antartica lipase-catalyzed esterification for efficient partial acylglycerol synthesis in solvent-free system: Substrate selectivity, molecular modelling and optimization

Partial acylglycerols are valued for their emulsifying and stabilizing properties, yet precise green synthesis remains challenging due to low yield and selectivity. This study aimed to elucidate the “lipase selectivity-substrate structure-product composition” relationship to enhance the yield of targeted partial acylglycerol. The results showed that lipase exhibited a greater selectivity towards fatty acids with shorter chain lengths and higher unsaturation. Hydroxyl donors also affected the esterification process, with the enzyme-acyl complex exhibiting selectivity towards hydroxyl donors as follows: glycerol > monoacylglycerol > diacylglycerol. Substrate ratio significantly influenced enzymatic reactions; a 10:1 ratio favored triacylglycerol formation (>80 %), while a 1:1 ratio produced > 90 % partial acylglycerols. Molecular docking simulations revealed that substrates primarily interacted with lipase through hydrogen bonding and hydrophobic interactions. A comprehensive understanding of lipase selectivity patterns could facilitate the design of more efficient reaction systems, enabling the conversion of basic lipid resources into desired high value-added products.

Pure Component and Binary Mixture Adsorption of Light Alkanes and Alkenes on Zeolite NaX at Low Temperatures: Influence of Chain Length.

In this study, the separation of short-chain alkane/alkene pairs by fixed-bed adsorption on zeolite NaX at low temperatures is investigated. Experiments are carried out with pure components and mixtures of ethane/ethene, propane/propene, and n-butane/1-butene in the temperature range between -75 and +40 °C and partial pressures up to 450 Pa. For a short chain length, much stronger adsorption of the alkene is observed. In contrast, with an increase in chain length, the isotherms of alkanes and alkenes of the same chain length become more similar. In addition, a greater influence of temperature on capacity is seen, the shorter the chain length is. In binary mixtures, a strong competition occurs at high total loadings with the alkene displacing the alkane. A characteristic curve is formed for the selectivity in the mixture, which shifts to higher temperatures with an increase in the chain length.

Weakened functional group activity enables the uniform distribution of the gel electrolyte to achieve the high-performance of Li-ion batteries

Electrolyte gelation is considered to be one of the main routes to solve the safety problem of liquid electrolytes. However, the distribution of gel polymer electrolyte (GPE) on the surface of electrodes and the mechanism of their effect on the performance of battery are still unknown. Here, methyl methacrylate (MMA) containing methyl (-CH3) and methyl-2-cyanoacrylate (MCA) containing cyanide (-CN) are employed as representative monomers to explore the relationship between gel distribution and battery performance. Due to the stronger electron-withdrawing properties, PMCA gel has shorter chain length and greater shrinkage, showing many cracks on the electrode surface, while PMMA gel can evenly cover the surfaces of electrodes. As a result, the capacity retention rate of 1.4 Ah NCM811/Gr pouch cells with PMMA is 93.5% for 500 cycles at 25 °C and 91.5% for 600 cycles at 60 °C, which these of the cells with PMCA are 58.8% for 266 cycles at 25 °C and 69.1% for 327 cycles at 60 °C. XPS analysis of the electrode sheets before and after cycling reveal that the PMCA-electrode has a large number of rzero valent lithium element precipitation, whereas the PMMA-electrode has the more stable interface film. This study indicates that the uniform distribution of gel electrolyte with -CH3 functional group on the electrode surface can improve the electrochemical performance of NCM811/Gr battery, which has the guiding significance.

Experimental and theoretical insight into the use of maleic anhydride copolymer and modified sulfamic acid for removing oilfield blockage

In the process of oil production, the problem of oilfield production decline due to blockage is becoming more and more serious. To improve the exploitation efficiency of traditional fuel, it is very important to remove the blockage and inhibit the formation of the blockage. In this study, the primary constituents of the blockages in this oilfield were identified as asphaltene (organic blockage) and calcium carbonate (CaCO3, inorganic blockage). To address these blockages, maleic anhydride copolymer (MAC-1, MAC-2, and MAC-3) with different chain lengths were polymerized by maleic anhydride and allyl polyoxyethylene ether, which were used to disperse organic blockages. Additionally, modified sulfamic acid (MSA-1, MSA-2, and MSA-3) with different chain lengths were synthesized by sulfamic acid, polyethylene glycol, and lauroyl chloride, which were used to dissolve inorganic blockages. The efficacy of these agents in terms of blockage removal, scale inhibition capability, corrosion rate, and compatibility with formation water were comprehensively evaluated. Results showed that MAC-2, which possesses a moderate chain length, and MSA-1, which has a shorter chain length, demonstrated an optimal synergistic effect on blockage dissolution at concentrations of 4 wt% for MAC-2 and 5 wt% for MSA-1. The dissolution rate of this combination was 81.18 %, with a scale inhibition rate of 95.7 %. The corrosion rate increased with temperature, and the agents maintained good compatibility with the formation water. To elucidate the mechanism underlying the effectiveness of MAC, the interaction between MAC and asphaltene was simulated by molecular dynamics (MD). These simulations indicated that MAC-2 and asphaltene exhibit the highest interaction energy (-64.2618 kcal/mol). Furthermore, we investigated the dissolution kinetics of CaCO3 in MSA solutions and determined that the reaction between MSA and CaCO3 was first-order, with a reaction rate constant of 1.6 × 10−2 min−1. The insights gained from this study offer a valuable experimental and theoretical foundation for enhancing productivity in similar oilfields.

Starch Characteristics and Amylopectin Unit and Internal Chain Profiles of Indonesian Rice (Oryza sativa).

Indonesia is arguably a major player in worldwide rice production. Though white rice is the most predominantly cultivated, red, brown, and red rice are also very common. These types of rice are known to have different cooking properties that may be related to differences in their starch properties. Investigating the starch properties, especially the fine structure of their amylopectin, can help understand these differences. This study aims to investigate the starch characteristics of some Indonesian rice varieties by evaluating the starch granule morphology and size, molecular characteristics, amylopectin unit and internal chain profiles, and thermal properties. Starches were extracted from white rice (long grain (IR-64) and short grain (IR-42)), brown rice, red rice, and black rice cultivated in Java Island, Indonesia. IR-42 had the highest amylose content of 39.34% whilst the black rice had the least of 1.73%. The enthalpy of gelatinization and onset temperature of the gelatinization of starch granules were between 3.2 and 16.2 J/g and 60.1 to 73.8 °C, respectively. There were significant differences between the relative molar amounts of the internal chains of the samples. The two white rice and black rice had a significantly higher amount of A-chains, but a lower amount of B-chains and fingerprint B-chains (Bfp) than the brown and red rice. The average chain length (CL), short chain length (SCL), and external chain length (ECL) were significantly longer for the red rice and the black rice in comparison to both the white rice amylopectins. The long chain length (LCL) and internal chain length (ICL) of the sample amylopectins were similar. Rice starches were significantly different in the internal structure but not as much in their amylopectin unit chain profile. These results suggest the differences in their amylopectin clusters and building blocks.

Unravelling molecular interactions in various alcohol-water binary mixtures using femtosecond laser-induced thermal lens spectroscopy

The FTLS (femtosecond laser-induced thermal lens spectroscopy) technique was utilized to explore the photothermal response and heat transfer dynamics in various water-based binary mixtures containing monohydric and polyhydric alcohols. Our results highlight the significant influence of intermolecular hydrogen bonding interactions and the molecular properties of the mixture constituents on the photothermal behavior of both pure solvents and their binary mixtures. Notably, we observed distinct effects of water inclusion on the heat transfer characteristics of monohydric alcohols (such as methanol and ethanol) compared to polyhydric alcohols (such as ethylene glycol (Etg) and glycerol (Gly)). This discrepancy can be attributed to the formation of unique molecular structures via hydrogen bonding interactions, which effectively hinders the natural molecular dynamics of short-chain length alcohols. Conversely, polyhydric alcohols like Etg and Gly exhibit contrasting photothermal characteristics due to their extensive intermolecular hydrogen bonding. Our investigations reveal that molecular attributes, such as chain length and the number of hydroxyl (-OH) groups, play a crucial role in altering the heat transfer mechanisms and thermal lens signal characteristics of the mixtures. These findings emphasize the sensitivity of FTLS as a probe for understanding the effects of intermolecular hydrogen bonding interactions on the molecular dynamics and thermo-optical properties of aqueous-alcoholic solutions.

Syntheses and properties of imidazopyridine-based ionic liquids

We have synthesized imidazopyridine-type ionic liquids and evaluated their properties. [Cnimpy][Br] (n = 4, 6, 8, 10), in which an alkyl group was introduced at the N1 position of imidazo[1,2-a]pyridine, were all solid at room temperature. Exchange of the counteranions of [Cnimpy][Br] with N(CN)2− and FSI− gave the ionic liquids [Cnimpy][N(CN)2] and [Cnimpy][FSI] in the liquid state at room temperature. In particular, the DSC thermogram of [C10impy][FSI] showed a clear melting point at 22 °C. In [Cnimpy][TFSI], ionic liquids consisting of cations with short alkyl chain lengths (n = 4,6) were solids at room temperature, while those with long alkyl chain lengths (n = 8,10) were liquids. [Cnimpy][FSI] has lower viscosity than other anion-consisting ionic liquids which showed a liquid state at room temperature. [Cnimpy][FSI] has lower viscosity than other anion-containing ionic liquids. In particular, [C4impy][FSI], with its relatively short alkyl chain length, exhibited a viscosity of 101 mPa·s at 25 °C, which renders it suitable for practical applications. [C4impy] [FSI] (50 μM acetonitrile solution) showed fluorescence with maximum absorption at 336 nm. Its fluorescence wavelength was shorter than that of imidazo[1,2-a]pyridine, whereas its fluorescence quantum yield (ΦF 0.39) was higher. Therefore, it is expected to be used as a composite material by employing FRET with a substance that exhibits fluorescence in the visible region.

Molecular Basis of the Granular Characteristics of Small-Granule Starch: A Comparative Study.

Small-granule starches (SGSs) have technological advantages over starches of conventional sizes for many applications. The study compared the granular characteristics of three SGSs (from amaranth, quinoa, and taro) with those of maize and potato starches and revealed their molecular basis. The results indicated that the supramolecular architecture of starch granules was not necessarily correlated with granule size. Acid hydrolysis of amaranth and quinoa starches was fast due to not only their small granule sizes but also the defects in the supramolecular structure, to which short external and internal chain lengths of amaranth and quinoa amylopectins contributed. By comparison, the granular architecture of taro starch granules was more stable partly due to the longer external chain length of taro amylopectin. Comparison of the molecular composition of branched subunits (released by using α-amylase of Bacillus amyloliquefaciens) in amylopectins and that in lintnerized starches suggested a significant heterogeneous degradation of amaranth and quinoa starches at supramolecular levels.

Structural elucidation and functional characteristics of novel potential prebiotics produced from Limosilactobacillus reuteri N1 GtfB-treated maize starches

The recently characterized Limosilactobacillus reuteri N1 GtfB (LrN1 GtfB) from glycoside hydrolase family 70 is a novel 4,6-α-glucanotransferase acting on starch/maltooligosaccharides with high enzyme activity and soluble protein yield (in heterogenous system). In this study, the influence of the treatment by LrN1 GtfB on the fine structure and functional characteristics of three maize starches were furtherly investigated and elucidated. Due to the treatment of LrN1 GtfB, the starch molecules were transformed into reuterans containing linear and branched (α1 → 6) linkages with notably smaller molecular weight and shorter chain length. Moreover, the (α1 → 6) linkage ratios in the GtfB-modified high-amylose maize starch (GHMS)/normal maize starch (GNMS)/waxy maize starch (GWMS) increased by 18.3 %/12.6 %/9.0 % as compared to their corresponding controls. In vitro digestibility experiment revealed that the resistant starch content of GHMS, GNMS and GWMS increased by 16 %, 18 % and 25 % as compared to the starch substrates. Furthermore, the butyric acid yielded from GHMS, GNMS and GWMS in the in vitro fermentation experiments were 1.4, 1.5 and 1.4 times higher than those of commercial galactose oligosaccharides. These results indicated that the highly-branched short-clustered reuteran synthesized by LrN1 GtfB might serve as novel potential prebiotics, and provide insights for the synthesis of promising prebiotic dietary fiber from starch.

Air-water interfacial properties of perfluorosulfonic acid salts with different chain lengths

Perfluorosulfonic acids (PFSA) are a class of per- and polyfluoroalkyl substances (PFAS), which have been extensively used in numerous applications. The toxicity and bioaccumulation of PFAS have become a serious worldwide problem. Foam fractionation has been suggested as a promising remediation method for PFAS removal owing to the amphiphilic nature of most of the currently existing PFAS in the environment, allowing them to migrate to the air-water interface during the foaming process. Nevertheless, the current challenge for widespread utilization of foam fractionation is its low removal efficiency, especially for short-chain PFAS. Foam fractionation performance depends on the air-water interfacial properties as well as the ability for PFAS to adsorb at the air-water interface. In the present study, therefore, we investigate surface tensions of PFSA with long and short chain lengths. Different adsorption models are studied to estimate maximum surface excess concentrations for various PFSA. Our results indicate that long-chain PFSA have lower surface tensions, higher surface activities, and form more rigid air-water interfaces. This study marks the first investigation of dilatational interfacial rheology of PFAS, as well as addressing the gap in understanding PFAS interfacial rheology by focusing on the quantification the storage and loss interfacial moduli, which are known to play a significant role in the foaming process.

Effects of the Molecular Structure of Malodor Substances and Their Masking on 1,2-Dioleoyl-sn-glycero-3-phosphocholine Molecular Layers.

Certain odors have been shown not only to cause health problems and stress but also to affect skin barrier function. Therefore, it is important to understand olfactory masking to develop effective fragrances to mask malodors. However, olfaction and olfactory masking mechanisms are not yet fully understood. To understand the mechanism of the masking effect that has been studied, the responses of several target substance (TS) molecules-1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) mixed molecular layers to odorant (OD) molecules were examined as a simple experimental model of epithelial cellular membranes injured by TS molecules. Here, we examined trans-2-nonenal, 1-nonanal, trans-2-decenal, and 1-decanal as TS molecules to clarify the effects of double bonds and hydrocarbon chain lengths on the phospholipid molecular layer. In addition, benzaldehyde and cyclohexanecarboxaldehyde were utilized as OD molecules to clarify the masking effect of the aromatic ring. Surface pressure (Π)-area (A) isotherms were measured to clarify the adsorption or desorption of TS and OD molecules on the DOPC molecular layer. In addition, Fourier transform infrared spectroscopy was performed to clarify the interactions among DOPC, TS, and OD molecules. We found that TS molecules with and without double bonds had different effects on the DOPC molecular layer and that molecules with shorter chain lengths had greater effects on the DOPC molecular layer. Furthermore, OD molecules with aromatic rings counteracted the effects of the TS molecules. On the basis of this research, not only a detailed mechanism by which odor molecules affect lipid membranes without mediating olfactory receptors is elucidated but also more effective OD molecules with masking effects are proposed.

Ultrastable Photodetectors Based on Blue CsPbBr3 Perovskite Nanoplatelets via a Surface Engineering Strategy.

Recently, photodetectors based on perovskite nanoplatelets (NPLs) have attracted considerable attention in the visible spectral region owing to their large absorption cross-section, high exciton binding energy, excellent charge transfer properties, and appropriate flexibility. However, their stability and performance are still challenging for perovskite NPL photodetectors. Here, a surface engineering strategy to enhance the optical stability of blue-light CsPbBr3 NPLs by acetylenedicarboxylic acid (ATDA) treatment has been developed. ATDA has strong binding capacity and a short chain length, which can effectively passivate defects and significantly improve the photoluminescence quantum efficiency, stability, and carrier mobility of NPLs. As a result, ATDA-treated CsPbBr3 NPLs exhibit improved optical properties in both solutions and films. The NPL solution maintains high PL performance even after being heated at 80 °C for 2 h, and the NPL film remains nondegradable after 4 h of exposure to ultraviolet irradiation. Especially, photodetectors based on the treated CsPbBr3 NPL films demonstrate exceptional performance, especially when the detectivity approaches up to 9.36 × 1012 Jones, which can be comparable to the best CsPbBr3 NPL photodetectors ever reported. More importantly, the assembled devices demonstrated high stability (stored in an air environment for more than 30 days), significantly exceeding that of untreated NPLs.

Investigating the anti-bioadhesion properties of short, medium chain length, and amphiphilic polyhydroxyalkanoate films

Silicone materials are widely used in fouling release coatings, but developing eco-friendly protection via biosourced coatings, such as polyhydroxyalcanoates (PHA) presents a major challenge. Anti-bioadhesion properties of medium chain length PHA and short chain length PHA films are studied and compared with a reference Polydimethylsiloxane coating. The results highlight the best capability of the soft and low-roughness PHA-mcl films to resist bacteria or diatoms adsorption as compared to neat PDMS and PHBHV coatings. These parameters are insufficient to explain all the results and other properties related to PHA crystallinity are discussed. Moreover, the addition of a low amount of PEG copolymers within the coatings, to create amphiphilic coatings, boosts their anti-adhesive properties. This work reveals the importance of the physical or chemical ambiguity of surfaces in their anti-adhesive effectiveness and highlights the potential of PHA-mcl film to resist the primary adhesion of microorganisms.