Surface Glass Transition Temperature Research Articles

Gelatine Blends Modified with Polysaccharides: A Potential Alternative to Non-Degradable Plastics.

Non-degradable plastics of petrochemical origin are a contemporary problem of society. Due to the large amount of plastic waste, there are problems with their disposal or storage, where the most common types of plastic waste are disposable tableware, bags, packaging, bottles, and containers, and not all of them can be recycled. Due to growing ecological awareness, interest in the topics of biodegradable materials suitable for disposable items has begun to reduce the consumption of non-degradable plastics. An example of such materials are biodegradable biopolymers and their derivatives, which can be used to create the so-called bioplastics and biopolymer blends. In this article, gelatine blends modified with polysaccharides (e.g., agarose or carrageenan) were created and tested in order to obtain a stable biopolymer coating. Various techniques were used to characterize the resulting bioplastics, including Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA)/differential scanning calorimetry (DSC), contact angle measurements, and surface energy characterization. The influence of thermal and microbiological degradation on the properties of the blends was also investigated. From the analysis, it can be observed that the addition of agarose increased the hardness of the mixture by 27% compared to the control sample without the addition of polysaccharides. In addition, there was an increase in the surface energy (24%), softening point (15%), and glass transition temperature (14%) compared to the control sample. The addition of starch to the gelatine matrix increased the softening point by 15% and the glass transition temperature by 6%. After aging, both compounds showed an increase in hardness of 26% and a decrease in tensile strength of 60%. This offers an opportunity as application materials in the form of biopolymer coatings, dietary supplements, skin care products, short-term and single-contact decorative elements, food, medical, floriculture, and decorative industries.

Correlation between fragility and surface glass transition temperature of polymers

The fragility of glass describes how rapidly its molecules slow down as it is cooled near its glass transition temperature. In nanoscale films, polymer glasses with higher fragility experience larger reductions in their Tg compared to those with lower fragility. We investigated whether this is due to the free surface of the polymers, which can cause the surface Tg (Tgsurf) to decrease relative to the bulk Tg. By measuring Tgsurf of various polymers, we found that the shift in Tgsurf relative to the bulk Tg increased with fragility. This suggests that more fragile polymers are more susceptible to the free surface effect. We explain this using the concept of energy landscape, as it is used to explain the different slowdown rates between strong and fragile glass formers at Tg.

Effects of elevated-temperature deposition on the atomic structure of amorphous Ta2O5 films

Brownian thermal noise as a result of mechanical loss in optical coatings will become the dominant source of noise at the most sensitive frequencies of ground-based gravitational-wave detectors. Experiments found, however, that a candidate material, amorphous Ta2O5, is unable to form an ultrastable glass and, consequently, to yield a film with significantly reduced mechanical loss through elevated-temperature deposition alone. X-ray scattering PDF measurements are carried out on films deposited and subsequently annealed at various temperatures. Inverse atomic modeling is used to analyze the short and medium range features in the atomic structure of these films. Furthermore, in silico deposition simulations of Ta2O5 are carried out at various substrate temperatures and an atomic level analysis of the growth at high temperatures is presented. It is observed that upon elevated-temperature deposition, short range features remain identical, whereas medium range order increases. After annealing, however, both the short and medium range orders of films deposited at different substrate temperatures are nearly identical. A discussion on the surface diffusion and glass transition temperatures indicates that future pursuits of ultrastable low-mechanical-loss films through elevated temperature deposition should focus on materials with a high surface mobility, and/or lower glass transition temperatures in the range of achievable deposition temperatueres.

Surface enthalpy recovery/relaxation of organic films determined by Mg deposition property

Estimating the surface glass transition temperature (T g) of materials is important for making organic devices by vacuum evaporation because the surface T g affects the interface of layered devices and their performance. The enthalpy state of organic films is related to T g. Bulk T g is ordinarily measured by differential scanning calorimetry (DSC), although there is no established method for measuring the surface T g. The Mg deposition property reflects the surface T g; no Mg deposition denotes a low surface T g. In this study, we investigated how annealing affects the bulk and surface T g of N,N′-Bis-(1-naphthalenyl)-N,N′-bis-phenyl-(1,1′-biphenyl)-4,4′-diamine (NPB) using DSC and the Mg deposition properties. For bulk NPB, enthalpy relaxation occurred after annealing at a temperature below T g. On the other hand, for vacuum-deposited NPB film, the enthalpy was in a relaxed state just after preparation, although the surface’s enthalpy recovered by annealing at same condition, as identified by the Mg deposition property.

Surface Glass Transition Temperature Region of Diarylethene Films Determined by Nano-Marangoni Effect.

For the last two decades, research has addressed whether the glass transition temperature and the molecular motions on the surface of organic films are significantly different from those inside the bulk glasses. It is reported that the surface of the photochromic diarylethene film prepared by vacuum deposition has fluidity and the vacuum deposition of small amount of rubrene molecules induces surface tension fluctuations, generating dents due to the Marangoni flow in nanoscale. The depth of the dents increases in proportion to these radii for the colorless diarylethene film with a bulk glass transition temperature (Tg) close to room temperature. On the other hand, in the colored diarylethene obtained by UV irradiation to the colorless film, the depth becomes constant at a certain level. The Tg distribution in the depth direction is clarified based on an analysis of the dent depth. By approximating the obtained Tg depth distribution with an exponential function, the outermost surface Tg is about 100 K lower than the bulk Tg in the case of photoisomerized diarylethene.

Adsorption of highly toxic chlorophenylacetonitriles on typical microplastics in aqueous solutions: Kinetics, isotherm, impact factors and mechanism

Microplastics (MPs) widely exist in all kinds of water bodies. The physical and chemical properties of MPs make them easy to become the carrier of pollutants, but the interaction between disinfection by-products (DBPs) and MPs has not been studied yet. In this study, the occurrence of emerging high-toxic chlorophenylacetonitriles (CPANs) in wastewater treatment plant (WWTP) effluents was determined. CPANs ubiquitously existed in WWTP effluents, and the concentration ranged from 88 ± 5 ng/L to 219 ± 16 ng/L. The typical MPs (i.e., polyethylene (PE), polyethylene terephthalate (PET), and polystyrene (PS)) were selected to study their adsorption of CPANs. Adsorption kinetics and isotherm analysis were carried out. The maximum Langmuir adsorption capacities were 8.602 ± 0.849 to 9.833 ± 0.946 μg/g for PE, 13.340 ± 1.055 to 29.405 ± 5.233 μg/g for PET, and 20.537 ± 1.649 to 43.597 ± 1.871 for PS. Dichloro-CPANs had higher adsorption capacity than monochloro-CPANs. After that, the specific surface area, contact angle, FTIR spectrum, crystallinity, and glass transition temperature (Tg) of MPs were measured. Based on the analysis of the properties of both MPs and CPANs, the mechanism of adsorption was studied. The adsorption of CPANs on PE was mainly affected by pore-filling and van der Waals force. In addition to these two factors, the adsorption of PET was also affected by hydrophobic interaction. Due to the substituents on the benzene ring, there was π-π interaction between PS and CPANs, which might be the reason why PS had the highest adsorption capacity for CPANs. Finally, the effects of pH and dissolved organic matter were studied, and their effects were relatively limited. The results indicated that MPs may adsorb CPANs in actual WWTP effluents, and special attention should be paid to the possible impacts on the aquatic environment caused by the transfer of CPANs on MPs.

Preparation and Characterization of Gelatin-Agarose and Gelatin-Starch Blends Using Alkaline Solvent.

Plastic waste is a serious problem in modern society. Every day, mankind produces tons of waste that must be disposed of or recycled. The most common types of plastic waste are disposable tableware, bags, packaging, bottles, and containers, and not all are recycled. Therefore, there is a great interest in producing environmentally friendly disposable materials. In this study, modified gelatin blends using polysaccharides (e.g., agarose, starch) were produced to obtain a stable coating. Various techniques were used to characterize the obtained bioplastics, including FTIR spectroscopy (Fourier-transform infrared spectroscopy), TGA (thermogravimetric analysis)/DSC (differential scanning calorimetry), contact angle measurements, and surface energy characterization. We also investigated the influence of thermal and microbiological degradation on the properties of the biocomposite. The addition of agarose increased the hardness of the blend by 27% compared to the control sample without added polysaccharides. Increases were also observed in the surface energy (24%), softening point (15%), and glass transition temperature (14%) compared to the control sample. The addition of starch to the biopolymer increased the softening point by 15% and the glass transition temperature by 6%. After aging, both blends showed an increase in hardness of 26% and a decrease in tensile strength of 60%.

Glass Transition of the Surface Monolayer of Polystyrene Films with Different Film Thicknesses and Supporting Surfaces

Surface glass-transition temperature (Tgsurf) and transition width (W) within 1 nm of the surface were measured by monitoring a qualitative change in the contact angle or density of end-groups (by time-of-flight secondary ion mass spectrometry) with temperature. Polystyrene (PS) films with various thicknesses (h) and molecular weights were studied. For unannealed PS supported on oxide-coated silicon or poly(dimethyl siloxane) with h > ∼60 nm, Tgsurf approached a plateau value of ∼25 K below the bulk Tg; below 60 nm, Tgsurf decreased with decreasing h. Separately, W exhibited a stepwise increase when h was decreased below the radius of gyration of the polymer. Upon thermal preannealing or deposition on a PS brush or adsorbed layer, the films ceased to exhibit Tgsurf reductions or stepwise change in W. We discuss how an out-of-equilibrium density profile with a deficit near the substrate and de Gennes’ sliding mode may explain these observations.

Correlation between the adsorption behavior of colloidal polymer particles and the yield stress of fresh cement pastes

Correlation between adsorption behavior of colloidal polymers on cement grains and yield stress of fresh cement pastes (fcps) is studied using four polymer latexes with varied surface charge density and glass transition temperature (Tg). Adsorption isotherm of the polymers is divided into two stages: before and after adsorption plateau. Higher charge density and lower Tg are beneficial to adsorption of polymer on cement grains. Before adsorption plateau, the adsorbed polymer particles play a bridging effect among cement grains which firstly increases and then decreases with increasing surface coverage ratio. Maximum bridging effect occurs at surface coverage ratio of ca. 20%. After adsorption plateau, yield stress of the fcps is significantly lower than that of the blank fcp because the adsorbed polymer layer reduces interaction force between cement grains, by increasing the minimum distance between two cement grains and generating repulsive force due to negative charges of the polymer particles.

Formulation, process, and storage strategies for lyophilizates of lipophilic nanoparticulate systems established based on the two models paliperidone palmitate and solid lipid nanoparticles

Lyophilization formulation and process development for lipophilic nanoparticle (NPs) products is highly challenging as the NPs have a low colloidal stability. We compared two different NP types, pure paliperidone palmitate nanocrystals and trimyristin solid lipid nanoparticles regarding formulation, process, and storage stability aspects. Freeze-thaw studies were conducted to investigate the basic formulation aspects such as buffer type, pH, and ionic strength as well as different cryoprotectants. In freeze-drying conventional ramp freezing was performed and compared to freezing with an annealing step added or with controlled ice nucleation. Different formulations were lyophilized and tested for short-term storage stability up to 6 weeks. Samples were analyzed for particle size, subvisible particle number, specific surface area, residual moisture, crystallinity, and glass transition temperature. Sucrose significantly better stabilized both NP types against freeze-thaw stress compared to mannitol demonstrating the importance of a fully amorphous matrix. While the impact of buffer type and pH was negligible, the aggregation propensity of NPs was reduced in presence of NaCl. The freezing step also impacted NP aggregation but the effect was less important than the formulation design. Surfactants did not necessarily improve the colloidal stability but resulted in a lower glass transition temperature of the lyophilizates and may cause phase separation which limits storage stability. This hurdle can be overcome by using a hydroxypropyl–β–cyclodextrin/ sucrose mixture as cryoprotectant. In general, we could show a similar freeze–drying behavior of the two NP types. Thus, we established a formulation and process approach to achieve stable lyophilizates of lipophilic NPs based on two different types of NPs. The general rules should be transferable to other NPs facilitating lyophilization development.

Fast Surface Dynamics on a Metallic Glass Nanowire.

The dynamics near the surface of glasses can be much faster than in the bulk. We studied the surface dynamics of a Pt-based metallic glass using electron correlation microscopy with sub-nanometer resolution. Our studies show an ∼20 K suppression of the glass transition temperature at the surface. The enhancement in surface dynamics is suppressed by coating the metallic glass with a thin layer of amorphous carbon. Parallel molecular dynamics simulations on Ni80P20 show a similar temperature suppression of the surface glass transition temperature and that the enhanced surface dynamics are arrested by a capping layer that chemically binds to the glass surface. Mobility in the near-surface region occurs via atomic caging and hopping, with a strong correlation between slow dynamics and high cage-breaking barriers and stringlike cooperative motion. Surface and bulk dynamics collapse together as a function of temperature rescaled by their respective glass transition temperatures.

Lateral diffusion of single poly(ethylene oxide) chains on the surfaces of glassy and molten polymer films.

Fluorescence correlation spectroscopy was used to show that the temperature-dependent diffusion coefficient of poly(ethylene oxide) (PEO) adsorbed on polystyrene and different poly(alkyl methacrylate) (PAMA) films in aqueous solution exhibited a maximum close to (but below) the surface glass transition temperature, Tgs, of the film. This elevated diffusion was observed over a small range of temperatures below Tgs for these surfaces, and at other temperatures, the diffusion was similar to that on silicon, although the diffusion coefficient for PEO on polystyrene at temperatures above Tgs did not completely decrease to that on silicon, in contrast to the PAMA surfaces. It is concluded that the enhanced surface mobility of the films near the surface glass transition temperature induces conformational changes in the adsorbed PEO. The origin of this narrow and dramatic increase in diffusion coefficient is not clear, but it is proposed that it is caused by a coupling of a dominant capillary mode in the liquid surface layer with the polymer. Friction force microscopy experiments also demonstrate an unexpected increase in friction at the same temperature as the increase in diffusion coefficient.

P(HEMA-co-EA) as host polymer for flexible dye-sensitized solar cell (DSSC) electrolyte

An electrolyte is the main component of a dye-sensitized solar cell (DSSC) which influences the efficiency of the DSSC. In order to prevent leakage problem and adhesive problem, new solid-state polymer electrolyte proposed rather than using a liquid electrolyte. For this research, new copolymers using 2-hydroxyethyl methacrylate (HEMA) and Ethyl Acrylate (EA) monomers are randomly copolymerized via UV-cure polymerization method with different ratio of each monomer (10,30,50,70,90) towards development as a solid-state electrolyte in flexible DSSC. In this study, the best ratio of the copolymer HEMA-co-EA will be the host polymer for electrolyte in DSSC. The most promising characteristics as a host in polymer electrolytes are due to its smooth cross-sectional surface and lowest glass transition temperature. Therefore, a best ratio of p(HEMA-co-EA) will be stirred with sodium iodide (NaI), Tetrahydro folic acid (THF) and iodine crystal for 24 hours to form a homogenous solution of an electrolyte. This p(HEMA-co-EA) will incorporate with different weight ratios of sodium iodide (NaI). This research reported that after 1500 s only three ratios of new host polymer p(HEMA-co-EA) were successfully copolymerized completely. All three ratio will be characterized by physical appearance, FTIR, DSC and XRD. By naked eyes, only 3 ratios of monomer (50HEMA:50EA, 70HEMA:30EA and 90HEMA:10EA) gave brittle structure which proved the copolymerization process completely success. For FTIR, those three ratios show the breakdown of a double bond at the HEMA monomer structure proved the complete copolymerization process. DSC shows that all three ratio shows the glass transition temperature (Tg) and only 50HEMA:50EA gave melting temperature (Tm) at 192.49°C and XRD confirmed the phase structure and crystallinity of three ratios. All these characterizations show that HEMA and EA monomers can be successfully random copolymerize with a three suitable ratio of each monomer and been used as an electrolyte for flexible DSSC.

Analysis of a Wide Range of Commercial Exterior Wood Coatings

This study was focused on measuring the properties of twenty-three commercially available coatings formulated for exterior wood applications. The coatings were characterized by measuring their surface tension, solid content, viscosity, pH, and glass transition temperatures (Tg). Additionally, the wetting properties of coating droplets on wood substrates were measured. The contact angle of solvent-based and water-based coatings were characterized on untreated southern yellow pine wood samples using high-resolution image analysis and the Young–Laplace solution. An innovative image processing technique for determining the average diameter of coating droplets on wood was developed, and an iterative method to calculate the average contact angle using the Young–Laplace solution was applied. The water-resistance of the coated wood samples was evaluated during one week of water immersion tests. In general, solvent-based coatings had significantly lower contact angles and water uptake than water-based coatings. Water-based paint samples had the largest average contact angle (81°), and solvent-based transparent penetrating stains had the smallest contact angle (13.9°). A strong correlation was observed between the coating water uptake and their surface tension and solid content.

Dynamic phase transitions in freestanding polymer thin films

After more than two decades of study, many fundamental questions remain unanswered about the dynamics of glass-forming materials confined to thin films. Experiments and simulations indicate that free interfaces enhance dynamics over length scales larger than molecular sizes, and this effect strengthens at lower temperatures. The nature of the influence of interfaces, however, remains a point of significant debate. In this work, we explore the properties of the nonequilibrium phase transition in dynamics that occurs in trajectory space between high- and low-mobility basins in a set of model polymer freestanding films. In thick films, the film-averaged mobility transition is broader than the bulk mobility transition, while in thin films it is a variant of the bulk result shifted toward a higher bias. Plotting this transition's local coexistence points against the distance from the films' surface shows thick films have surface and film-center transitions, while thin films practically have a single transition throughout the film. These observations are reminiscent of thermodynamic capillary condensation of a vapor-liquid phase between parallel plates, suggesting they constitute a demonstration of such an effect in a trajectory phase transition in the dynamics of a structural glass former. Moreover, this transition bears similarities to several experiments exhibiting anomalous behavior in the glass transition upon reducing film thickness below a material-dependent onset, including the broadening of the glass transition and the homogenization of surface and bulk glass transition temperatures.

Be Aggressive! Amorphous Excipients Enabling Single-Step Freeze-Drying of Monoclonal Antibody Formulations.

Short freeze-drying cycles for biopharmaceuticals are desirable. Formulations containing an amorphous disaccharide, such as sucrose, are prone to collapse upon aggressive primary drying at higher shelf temperature. We used 2-hydroxypropyl-betacyclodextrin (HPBCD) in combination with sucrose and polyvinylpyrrolidone (PVP) to develop an aggressive lyophilization cycle for low concentration monoclonal antibody (mAb) formulations. Glass transition temperature and collapse temperature of the formulations were determined, and increasingly aggressive cycle parameters were applied. Using a shelf temperature of +30 °C during primary drying, the concept of combining sublimation and desorption of water in a single drying step was investigated. Cake appearance was evaluated visually and by micro-computed tomography. Lyophilisates were further analyzed for reconstitution time, specific surface area, residual moisture, and glass transition temperature. We demonstrated the applicability of single-step freeze-drying, shortening the total cycle time by 50% and providing elegant lyophilisates for pure HPBCD and HPBCD/sucrose formulations. HPBCD/PVP/sucrose showed minor dents, while good mAb stability at 10 mg/mL was obtained for HPBCD/sucrose and HPBCD/PVP/sucrose when stored at 40 °C for 3 months. We conclude that HPBCD-based formulations in combination with sucrose are highly attractive, enabling aggressive, single-step freeze-drying of low concentration mAb formulations, while maintaining elegant lyophilisates and ensuring protein stability at the same time.

Impact behavior and fractography of additively manufactured polymers: Laser sintering, multijet fusion, and hot lithography

To reduce the lead time, polymer fuel tanks could be toollessly produced using additive manufacturing (AM) technologies. Detailed knowledge of the performance of AM polymers is essential for the design and development of such components. In instrumented static (0.01 mm/s) and dynamic (2.5 m/s) three-point bending and puncture tests, the impact behaviors of polyamide and methacrylate-based photopolymer test specimens were compared. The polyamide test specimens were produced by laser sintering and multijet fusion, and the photopolymer test specimens were produced by a hot lithography process. Fractography was performed using stereo light and scanning electron microscopy to investigate the fracture surface morphology. The test results were used to analyze the relationships among the surface roughness, shear modulus, and glass transition temperature. The AM polymers revealed comparable force–displacement behaviors in a static three-point bending test, but their impact behaviors differed greatly. The obtained results highlight that the impact performance of AM polymers is an essential design variable for fluid-containing parts.

Glass transition of a polystyrene surface as detected via two-dimensional diffusion of Au atoms during physical vapor deposition

We investigated two-dimensional diffusion of Au atoms across the surface of a polystyrene (PS) film during physical vapor deposition to determine the surface glass transition temperature (Tg). Deposited Au atoms underwent two-dimensional diffusion on the PS surface until they coalesce with other atoms or aggregated particles. The diffusivity of Au on the PS surface was evaluated from the size and the number density of yielded Au nanoparticles. The diffusion coefficient D of Au was found to exhibit a drastic change near 356 K, which was assigned to the surface Tg of the PS substrate. A stronger temperature dependence of D observed near Tg suggests that Au diffusion is coupled with the segmental dynamics of PS. The change in the diffusion coefficient suggests an essential difference in the diffusion mechanism below and above the Tg of the PS surface. We assume that diffusion on a glassy PS surface reflects a more heterogeneous feature of the PS surface than that above Tg. This was qualitatively supported by the results from Monte Carlo simulations with varying activation energy distributions.

Surface molecular kinetics on the outermost layer characterized by nucleation of Mg-vapor atoms

The state of organic surfaces/interfaces greatly affects the performance of organic electronic devices. Various methods have been reported to investigate the surface glass transition temperature, which is based on the dynamics of molecules or polymer chains existing at the depth of several to several-tens nanometers from surface. However, no report has published about the characterization of molecular kinetics on the outermost surface. We report that the surface nucleation of Mg-vapor atoms reflects the molecular kinetics on the outermost surface. The nucleation rate of vaporized atoms/molecules is generally accelerated on steps existed on crystalline surface, to the contrary we found suppressed nucleation of Mg nanocrystals around the steps on a diarylethene crystalline surface during Mg-vapor deposition. On the other hand, Pb, Bi, and Te nanocrystals tended to accumulate the steps. The difference between acceleration and suppression of metal nucleation on the steps was attributed to molecular kinetics on the outermost surface and intensity of van der Waals interaction between metal atoms and the molecules. Mg having the weak interaction with organic molecules is suitable for characterizing molecular kinetics on the outermost surface. The observation of Mg nucleation can play a role in measuring molecular kinetics on the outermost surfaces. The state of organic surfaces/interfaces greatly affects the performance of organic electronic devices. Various methods have been reported to investigate the surface glass transition temperature, which is based on the dynamics of molecules or polymer chains existing at the depth of several to several-tens nanometers from surface. However, no report has published about the characterization of molecular kinetics on the outermost surface. We report that the surface nucleation of Mg-vapor atoms reflects the molecular kinetics on the outermost surface. The nucleation rate of vaporized atoms/molecules is generally accelerated on steps existed on crystalline surface, to the contrary we found suppressed nucleation of Mg nanocrystals around the steps on a diarylethene crystalline surface during Mg-vapor deposition. On the other hand, Pb, Bi, and Te nanocrystals tended to accumulate the steps. The difference between acceleration and suppression of metal nucleation on the steps was attributed to molecular kinetics on the outermost surface and intensity of van der Waals interaction between metal atoms and the molecules. Mg having the weak interaction with organic molecules is suitable for characterizing molecular kinetics on the outermost surface. The observation of Mg nucleation can play a role in measuring molecular kinetics on the outermost surfaces. • The surface nucleation of Mg-vapor atoms reflects the molecular kinetics on the outermost surface. • We found suppressed nucleation of Mg nanocrystals around the steps on a diarylethene crystalline surface. • The suppressed nucleation was attributed to surface molecular kinetics and weak van der Waals interaction.

Effects of extraction procedures and plasticizer concentration on the optical, thermal, structural and antioxidant properties of novel ulvan films

Active films were produced with sulphated polysaccharides “ulvan”, extracted from the green seaweed Ulva lactuca with different extraction procedures, by varying the glycerol or sorbitol plasticizer concentration at 1% and 2% (w/v). The surface charge and glass transition temperature (Tg) of ulvans were carried out by zeta (ζ)-potential and DSC analysis, respectively. The investigation revealed that ulvans were anionic stable polymers and they had great Tg values. Regardless of the extraction procedure, ulvans can give successful films formulations. However, the optical, thermal, structural and antioxidant characteristics of ulvan films were strongly affected by extraction conditions and by the variation of the type and concentration of plasticizer. In general, as plasticizer concentration increased, ferrous chelating activity and compact structure increased as well, while, Tg, lightness and DPPH radical-scavenging activity decreased. Interestingly, the films plasticized with glycerol exhibited better compact structure, more negative temperature of transition, and greater free radical scavenging ability than with sorbitol. However, the films prepared with sorbitol had the highest L* values and chelating ability. The current study revealed a high correlation between zeta (ζ)-potential of ulvans and their Tg (R2 = 0.98), as well as with scavenging activity of ulvan films (R2 = 0.8–0.99).