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This study investigates the development and characterization of chitosan, gelatin, and chitosan/gelatin (Chi/Gel) bioaerogel composites through a facile and eco-friendly approach. The goal is to optimize their structural and functional properties for potential environmental and biomedical applications. Direct freezing and lyophilization approach were used to prepare the aerogels, the focus was on investigating the effects of blending ratios on the density, porosity, surface area, and water absorption capabilities of the aerogels. The results show that Chi/Gel 60/40 composition achieved an optimal balance of structural robustness and functional performance, characterized by a moderate density of 74.2 mg/[cm.sup.3], the highest porosity among the samples at 93.5%, an impressive surface area of 184.8 [m.sup.2]/g, and a water absorption capacity of 28.8 g/g. These results suggest that the synergistic effect of chitosan and gelatin at specific ratios significantly enhances the overall properties of the material. Our findings suggest that Chi/Gel bioaerogels, especially the 60/40 composite, hold great promise for diverse applications. Highlights * All Gelatin/Chitosan bioaerogels exhibited high porosity and low density. * The Chi/Gel 60/40 mix achieved the highest porosity and surface area. * Highest water adsorption was observed in the Chi/Gel 60/40 composite. * Synergistic effects enhanced properties of the Gelatin/Chitosan scaffolds. KEYWORDS bioaerogel, biopolymers, chitosan, eco-friendly, gelatin, porose materials, 1 | INTRODUCTION In recent years, the focus has shifted towards developing aerogels from biopolymers due to their biocompatibility, biodegradability, and abundance. (1,2) Bioaerogels, known for their extraordinary lightweight and [...]

A new, low-cost, and direct green synthesis strategy was developed for the preparation of polymer composites composed of silver nanoparticles (AgNPs) decorated on a shape memory polymer blend using Rubus caesius L. leaves. X-ray powder diffraction, ultraviolet-visible spectroscopy (UV-vis), scanning electron microscopy, and energy dispersive X-ray spectroscopy (EDS) elemental composition were applied to characterize the crystal size, morphology, and elemental composition of Ag-NPs. UV-vis spectra detected the characteristic absorbance signal of AgNPs at about 430 nm, and the average crystal size of nanoparticles was calculated as about 12.60 nm. When nanocomposite films were characterized by attenuated total reflectance infrared spectroscopy, characteristic polylactic acid, and poly ethylene glycol (PEG) signals were determined. From the thermogravimetric analysis curves, it was determined that the amount of residue of nanocomposites increased as the amount of AgNP increased. It was seen that AgNPs did not affect the [T.sub.g] temperature of the nanocomposite films, while it was also a proof that the polymer blend was immiscible. It was observed that the shape recovery properties of nanocomposite films were better with increasing AgNPs content. Finally, both green synthesized AgNPs and nanocomposites prepared with shape memory polymers showed very good antibacterial activity against Gram-positive and Gram- negative bacteria. Highlights * Green synthesis of silver nanoparticles (AgNPs) was carried out with Rubus caesius L. leaves. * The synthesized AgNPs were characterized by ultraviolet visible spectroscopy and x-ray powder diffraction. * Composite films were prepared with poly lactic acid/poly [epsilon]- caprolactone blend by solvent casting method. * The amount of residue of nanocomposites increased with increasing AgNPs percentage. * The nanocomposite film containing 10% AgNPs has good activity. KEYWORDS antibacterial, green synthesis silver nanoparticles, nanocomposite, poly [epsilon]-caprolactone, poly lactic acid, shape memory effect, 1 | INTRODUCTION Nanoscale materials ranging from 1 to 100 nm are thought to provide solutions to environmental and technological challenges in medicine and water treatment. (1,2) This increasing demand [...]

3D printing (3DP) has brought endless possibilities to the manufacturing industry. Biodegradable high-polymer materials such as polylactic acid (PLA) and polycaprolactone (PCL) have attracted widespread attention. However, to optimize printing performance, this study prepared six PLA/PCL composite materials with ratios of 4:6, 5:5, and 6:4, by adding Polyethylene Glycol 4000 (PEG 4000) as a plasticizer and nano silica as a reinforcing agent. Parameters that can affect printing quality, including formulation, printing temperature (150, 170, and 190[degrees]C), filling density (305, 40%, and 50%), and printing speed (20, 30, and 40 mm/s), were examined and optimized. The optimal factor level combination determined by Taguchi fractional factorial design were silica addition 0.6 g, PLA content 60 wt%, printing temperature 190[degrees]C, infill density 50%, and printing speed 20 mm/s. The obtained minimum error value was 0.338 mm. Analysis of variance revealed the statistical significance of PLA content and printing temperature. A general linear model was established for result prediction, showing a difference of 9.25% from the actual error values. SEM results indicated poor compatibility between PLA and PCL in the melt-blended mixture, while the addition of Si[O.sub.2] nanoparticles facilitated PCL and PLA crystallization. DSC analysis demonstrated that the incorporation of PLC and Si[O.sub.2] led to an increase in crystallinity, with 5PLA/5PCL/Si[O.sub.2] exhibiting the highest crystallinity at 51.4%. Tensile testing results showed that the addition of 50 wt% PCL to PLA significantly improved the fracture elongation of the PLA/PCL material with a 5:5 formulation, averaging about 4 times higher than that of pure PLA, while the tensile strength decreased by 1.5 times. This study not only expands the research on PLA/PCL blends but also provides process guidance for 3D printing of the materials. KEYWORDS 3D printing, PCL, PLA, Si[O.sub.2], Taguchi design and optimization, 1 | INTRODUCTION Under the guidance of Industry 4.0, a revolution to smarten and digitize everything and everywhere is occurring in almost eveiy industrial sector including the manufacturing industry. One [...]

A new high waterproof and flame-retardant material was developed by using polylactic acid as a binder. Fireproof composite materials have excellent physical, mechanical, and flame-retardant properties. The water resistance property of fireproof composites increases as the polylactic acid doping ratio increases. Also, the mechanical performance test showed that the flexural strength of the composite materials reached 14.75 MPa a polylactic acid amount of 25 wt%. More so, the surface of the inorganic materials (magnesium hydroxide and aluminum hydroxide), were uniformly covered by the polylactic acid providing good interfacial compatibility between the inorganic materials and polylactic acid. The results of scanning electron microscopy showed that the fracture cross-section of the composites was smooth and dense. Thermogravimetric analysis and fire resistance testing further confirmed that the fireproof materials have good thermal stability. The as-prepared composite materials with improved physical and mechanical properties could be utilized to partitions in public buildings, non-load bearing walls, and a sandwich for fire doors. KEYWORDS composite materials, flame-retardant, mechanical properties, polylactic acid, waterproof, 1 | INTRODUCTION For the past few years, people's lives and property have been seriously threatened by the frequent occurrence of fire disaster around the world, which has made the [...]

The objective of this study was to investigate the wear resistance of ultrahigh-molecular weight polyethylene (UHMWPE) and crosslinked polyethylene (XLPE) against different counterfaces. Friction and wear studies were evaluated under dry reciprocating sliding conditions at room temperature. TI6AI4V discs finished in polished, lapped, and ground conditions were reciprocated against polymer cylinders. In addition, abrasive wear studies were conducted using different abrasive grit sizes. The friction and wear properties of the two polyethylenes were strongly affected by the different counterfaces. XLPE showed important friction and wear sensitivity with the change of surface roughness of the TI6AI4V disc, as well as with the change in abrasive grit size. Scanning electron microscopy and energy-dispersive X-ray (EDX) analysis of the worn disc surfaces and the polymer pins indicated the wear mechanisms affecting the polyethylenes., INTRODUCTION Ultrahigh-molecular weight polyethylene (UHMWPE) and crosslinked polyethylene (XLPE) are extensively used biopolymers as a bearing material in total joint replacements (TJRs) [1], UHMWPE was used as a gold-standard material [...]

The weldability of polylactic acid (PLA) is examined in this article. Biaxially oriented PLA films of various thicknesses were joined with impulse and ultrasonic welding techniques. Relatively high weld strengths were achieved with impulse welding over a wide range of welding parameters. Ultrasonic welding produced high weld strengths with relatively short cycle times. In detail, ultrasonic welded samples had a weld factor (weld strength/base material strength) of 1 at cycle times of 0.25 sec. The weld factor was significantly lower at shorter weld times and weld times above 0.35 sec. In contrast, 100-µm thick samples joined by impulse welding for 2-3 sec had a weld factor of 1 and a standard deviation of only [+ or -]5%. The peak temperature during the impulse welding was measured to determine the fusion temperatures of the films. Mechanical, thermal, and optical analysis was used to examine the properties of the PLA at various welding and annealing conditions. POLYM. ENG. SCI., 51:1059-1067, 2011. [C] 2011 Society of Plastics Engineers, INTRODUCTION Polylactic acid (PLA), a biodegradable polymer derived from lactic acid, is made from 100% renewable resources such as sugar beets, wheat, corn, or other starch-rich crops. The starch from [...]

One of the possible methods for 3D protein structure investigation is the study of gas-phase hydrogen/ deuterium (H/D) exchange reaction between protein ions and a D-containing reactant gas, e.g., [D.sub.2]O or N[D.sub.3]. A segmented radio frequency quadrupole (RFQ) was used as a molecule-ion reactor to study gas-phase H/D-exchange of protonated ions of three different peptides. The ions were produced in an electrospray ion source. The RFQ is a part of ion transport interface of a high resolution orthogonal time-of-flight mass spectrometer (O-TOF MS). The RFQ was modified for a linear ion trap (LIT) mode of operation to increase a dwell time of target ions inside the RFQ. Phase-sensitive operation of the LIT and the O-TOF MS was controlled by custom developed PC executive program. The reaction mixture of [N.sub.2] and N[D.sub.3] was injected into the reactor, while keeping its partial pressure in the range of [10.sup.-3] -[10.sup.2] mbar, and corresponding N[D.sub.3] concentration in the range of [10.sup.13]-[10.sup.14] [cm.sup.-3]. It was possible to vary the ion dwell time in the reactor between 30 ms and 1 s. H/D-exchange was studied for leucine enkephalin, gramicidin S and apamin. The data analysis based on statistical approach has shown a principal possibility to distinguish different mobile H-atoms of peptides, taking part in H/D-exchange, according to reaction rates. Keywords: H/D-exchange, ion-molecular reactions kinetics, conformation structure of biomolecules, segmented radio-frequency quadrupole DOI: 10.1134/S1061934810140121, INTRODUCTION Gas-phase polypeptide and protein ions are unique objects for the fundamental research of intramolecular forces superimposed between different parts of a single ion. The parameters of the intramolecular forces [...]

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2010.07.022 Byline: T. Kuppens (a), T. Cornelissen (b), R. Carleer (b), J. Yperman (b), S. Schreurs (c), M. Jans (c), T. Thewys (a) Abstract: The disposal problem associated with phytoextraction of farmland polluted with heavy metals by means of willow requires a biomass conversion technique which meets both ecological and economical needs. Combustion and gasification of willow require special and costly flue gas treatment to avoid re-emission of the metals in the atmosphere, whereas flash pyrolysis mainly results in the production of (almost) metal free bio-oil with a relatively high water content. Flash co-pyrolysis of biomass and waste of biopolymers synergistically improves the characteristics of the pyrolysis process: e.g. reduction of the water content of the bio-oil, more bio-oil and less char production and an increase of the HHV of the oil. This research paper investigates the economic consequences of the synergistic effects of flash co-pyrolysis of 1:1 w/w ratio blends of willow and different biopolymer waste streams via cost-benefit analysis and Monte Carlo simulations taking into account uncertainties. In all cases economic opportunities of flash co-pyrolysis of biomass with biopolymer waste are improved compared to flash pyrolysis of pure willow. Of all the biopolymers under investigation, polyhydroxybutyrate (PHB) is the most promising, followed by Eastar, Biopearls, potato starch, polylactic acid (PLA), corn starch and Solanyl in order of decreasing profits. Taking into account uncertainties, flash co-pyrolysis is expected to be cheaper than composting biopolymer waste streams, except for corn starch. If uncertainty increases, composting also becomes more interesting than flash co-pyrolysis for waste of Solanyl. If the investment expenditure is 15% higher in practice than estimated, the preference for flash co-pyrolysis compared to composting biopolymer waste becomes less clear. Only when the system of green current certificates is dismissed, composting clearly is a much cheaper processing technique for disposing of biopolymer waste. Author Affiliation: (a) Research Group Environmental Economics and Law, Centre for Environmental Sciences, Hasselt University, 3590 Diepenbeek, Belgium (b) Laboratory of Applied and Analytical Chemistry, Centre for Environmental Sciences, Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek, Belgium (c) NuTeC, Department TIW, XIOS, Agoralaan Gebouw H, 3590 Diepenbeek, Belgium Article History: Received 25 August 2009; Revised 22 June 2010; Accepted 19 July 2010

Natural rubber and other natural polyisoprenoids are the only biopolymers whose cleavage by enzymes is still mostly unknown. However, a considerable progress is made in the understanding of microbial rubber degradation.

A high-lignin-content softwood kraft pulp was reacted with laccase in the presence of 1-hydroxybenzotriazole (HBT), N-acetyl-N-phenylhydroxylamine (NHA), and violuric acid (VA). The biodelignification response with violuric acid was superior to both 1-hydroxybenzotriazole and N-acetyl-N-phenylhydroxylamine. NMR analysis of residual lignins isolated before and after the biobleaching treatments revealed that the latter material was highly oxidized and that the magnitude of structural changes was most pronounced with the laccase--violuric acid biobleaching system. An increase in the content of carboxylic acid groups and a decrease in methoxyl groups were noted with all three laccase-mediator systems. The oxidation biobleaching pathway is directed primarily towards noncondensed C5 phenolic lignin functional structures for all three laccase-mediated systems. The laccase--violuric acid system was also reactive towards C5-condensed phenolic lignin structures. Key words: laccase, mediator, lignin, pulp, biobleaching, phenolics.

Research has been conducted on the responses of the biopolymer processes. The use of vapor pressure osmometry in determining the isoosmolal preferential interaction coefficients is discussed.

The Ramachandran potential of mean force for the alpha(1->4)-linked dimer of D-xylopyranose in TIP3P solution has been computed through molecular dynamic simulations using the adaptive umbrella sampling method. D-xylopyranose is a pentose analogue of maltose and is used in studying the effects of solvent structuring upon biopolymer hydration. Results reveal that hydration can significantly affect the conformational equilibrium of biopolymers in solution. This finding agrees with previous pmf studies of peptides in solution.

Dendrimers, the most highly branched structures achievable, have found numerous uses in the chemical, biological, and pharmaceutical fields. We have employed size exclusion chromatography (SEC) with universal calibration to determine molecular weight averages, distributions, intrinsic viscosities, and structural parameters of Starburst dendrimers, dextrans, and the starch degradation polysaccharides known as maltodextrins. Comparisons have been made in the dilute solution behavior of dendrimers and polysaccharides with equivalent weight-average molecular weights. Intrinsic viscosities decreased in the order [[[Eta]]].sub.dextran] > [[[Eta]]].sub.dextrin] > [[[Eta]].sub.dendrimer]. While the difference between dendrimer and polysaccharides may be attributed to the higher branching of the former, which leads to a higher chain density in solution, the difference between dextran and dextrin is likely a result of the variation in solution behavior of [Alpha]-(1-6) vs [Alpha]-(1-4) linked carbohydrates. The solution behavior of the maltodextrins studied indicates that debranching in their manufacture appears to have been more thorough than in that of [Beta]-limiting dextrins studied by other groups. Comparison of molecular radii obtained from SEC data to radii from molecular dynamics studies show Starburst dendrimers behave as [Theta]-stars with functionality between 1 and 4. Additionally, electrospray ionization mass spectrometry was employed to determine [M.sub.w], [M.sub.n], and PD of Astramol dendrimers.

Light scattering measurements and polarization photometry were utilized to investigate the opposite effects of electrostatics and steric exclusion on bundle formation by F-actin and other filamentous polyelectrolytes. Results have shown that the formation of the bonds between proteins was determined by the complementary surfaces on each protein. These sites were determined by the amino acid sequences, the secondary and the tertiary structure that allow juxtaposition of the binding site.

A combination of in situ and ex situ surface plasmon resonance (SPR) imaging experiments is used to characterize the differential electrostatic adsorption of proteins and synthetic polypeptides onto photopatterned mono-layers at gold surfaces. The nonspecific electrostatic adsorption of proteins onto negatively charged self-assembled monolayers (SAMs) of 11-mercaptoundecanoic acid (MUA) is found to depend on the protein pI, solution ionic strength, and solution pH. The pH dependence of the electrostatic adsorption of the protein avidin onto a MUA SAM indicates that a full monolayer adsorbs at a solution pH greater than 5.0, and an 'effective p[K.sub.a]' of 3.6 is determined for the avidin adsorption. This effective pKa is a combination of the p[K.sub.a] of the MUA monolayer and the ion pairing adsorption coefficient for the avidin. Additional SPR imaging experiments show that the electrostatic adsorption of the synthetic polypeptide poly-L-lysine (PL) onto a MUA SAM varies with molecular weight, forming a full PL monolayer for polypeptides with more than 67 lysine residues.