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The investigation of protein–nanoparticle interactions contributes to the understanding of nanoparticle bio-reactivity and creates a database of nanoparticles for use in nanomedicine, nanodiagnosis, and nanotherapy. In this study, hen's egg white was used as the protein source to study the interaction of proteins with sulphuric acid hydrolysed nanocellulose (CNC). Several techniques such as FTIR, zeta potential measurement, UV–vis spectroscopy, compressive strength, TGA, contact angle and FESEM provide valuable information in the protein–CNC interaction study. The presence of a broader peak in the 1600–1050 cm−1 range of CNC/egg white protein FTIR spectrum compared to the 1600–1050 cm−1 range of CNC sample indicated the binding of egg white protein to CNC surface. The contact angle with the glass surface decreased with the addition of CNC to egg white protein. The FESEM EDX spectra showed a higher amount of N and Na on the surface of CNC. It indicates the density of protein molecules higher around CNC. The zeta potential of CNC changed from −26.7 ± 0.46 to −21.7 ± 0.2 with the introduction of egg white protein due to the hydrogen bonding, polar bonds and electrostatic interaction between surface CNC and protein. The compressive strength of the egg white protein films increased from 0.064 ± 0.01 to 0.36 ± 0.02 MPa with increasing the CNC concentration from 0 to 4.73% (w/v). The thermal decomposition temperature of CNC/egg white protein decreased compared to egg white protein thermal decomposition temperature. According to UV–Vis spectroscopy, the far-UV light (207–222 nm) absorption peak slightly changed in the CNC/egg white protein spectrum compared to the egg white protein spectrum. Based on the results, the observations of protein nanoparticle interactions provide an additional understanding, besides the theoretical simulations from previous studies. Also, the results indicate to aim CNC for the application of nanomedicine and nanotherapy. A new insight given by us in this research assumes a reasonable solution to these crucial applications.

Photothermal therapy (PTT) has been extensively explored as a promising alternative therapeutic approach for many malignant tumors. However, PTT agents never repair bone defects because of their lack of osteogenic activity. Therefore, the integration of multi-modal therapies into one platform could show great promise in overcoming the drawbacks of conventional single-modal therapy and achieving improved therapeutic efficacy in cancer. In this study, an indocyanine green (ICG) and diethylenetriamine/nitric oxide adduct (DETA/NO)-loaded polylactic acid (PLA) (PLIN) monolith was created via simple thermally induced phase separation (TIPS) and used to enhance PTT efficacy by killing residual cancer cells and regenerating bone defects after surgical resection of tumor tissues. The resulting PLIN monolith exhibited interconnected microporous structures and uniform morphology composed of leaf-like small units. The results of in vitro PTT efficacy tests demonstrated that the PLIN monolith exhibited enhanced photothermal activity on osteosarcomas but did not caused phototoxicity in normal osteoblasts. The synergistic cancer therapy efficacy of PLIN was mainly caused by high local temperature and elevated intracellular generation of ONOO− in MG63 cells. In addition, PLIN induced significant apoptotic cell death following laser irradiation. Therefore, the PLIN monolith has potential for application in osteosarcoma therapy and bone regeneration.

Electrolyte is one of the main components of dye sensitized solar cell (DSSC) preparation. Electrolyte is an ionic charge transfer medium between charge and discharge. In order to improve and study the performance of electrolyte in the DSSC, different sized iodide salts have been applied. In this review, the effect of different type of iodide salts in the performance of electrolyte and DSSC were presented. Single and binary salt systems usage in DSSC with iodide salt for solar conversion efficiency, ionic conductivity and properties were presented. Single salt which is in large/bulky sized able to enhance the ionic conductivity while for the small sized iodide salt, it give higher solar conversion efficiency. As both small and large sized iodide salt combine, it will reveal a better result in ionic conductivity and solar conversion efficiency in DSSC. Furthermore, DSSC was discovered by Hermann Wilhelm Vogel in 1873 which related to the color of photography. He found out that addition of green dye will make the photographic films more sensitive to the light at longer wavelength. About 118 years later, DSSC was first carried out by O’regan and Gratzel.

In this study, we contribute the facile fabrication of tough polyolefin monoliths from their polymer solutions using a phase separation method. Compressive stress–strain tests demonstrate that the monoliths have excellent mechanical properties. The monoliths show macroporous structures where the pore sizes can be tuned from sub-1 to 16 µm by adjusting the fabrication conditions. The monoliths exhibit high hydrophobicity/ oleophilicity and good resistance toward different chemicals. Based on the above properties, we applied the monoliths to the selective absorption of oil from an oil/water mixture. By simply squeezing the monoliths, the absorbed oil can be recovered. The monoliths are useful for more than 10 cycles of absorption and recovery, showing a good stability for industrial-scale oil spill treatment.

Millions of tons of used cigarette filters (UCF) are worldwide discarded in the environment as toxic waste. This study provides a new application of UCF for energy storage in order to contribute to solution to environmental concerns by UCF. We have developed a facile method to fabricate nitrogen-doped hierarchical porous carbons by a combination of UCF and polypyrrole (PPy). The carbonization and activation of the as-obtained composite by KOH afforded the carbon material of very high surface area (3420 m2/g) with micro-, meso-, and macroporous structures. The nitrogen content measured by X-ray photoelectron spectroscopy was 2.34%, which is derived from PPy. The formed carbon showed large specific capacitance of 263 F/g at 1 A/g and good capacitance retention of 90% even after 5000 cycles at the current density of 5 A/ g. These excellent data are owing to the 3D hierarchical porous structure and nitrogen-doped functionality of the present carbon and UCF is regarded as a potential candidate of a carbon precursor for high-performance supercapacitors. Furthermore, this study affords a new way to recycle UCF with valuable applications, contributing to reduction of environmental pollution by UCF.

This study investigates an alternative green strategy based on non-toxic and readily biodegradable chlorocholine chloride/urea deep eutectic solvents (DESs), which act both as functionalization agents and solvents that allow for the cationization of cellulose monoliths to form novel adsorbents for removal of anionic reactive dye from water. Cellulose monolith was produced by deacetylation of cellulose acetate monolith which was fabricated via thermally induced phase separation (TIPS) method using binary solvents of DMF and 1-hexanol. Cationization of cellulose monolith was confirmed by SEM, FTIR, elemental analysis, TGA and BET surface area analysis. For the flow-through applications, the permeability and mechanical properties were also analysed in this study. The cationized cellulose monoliths were employed to remove acid red 70 dye from aqueous solutions in dynamic adsorption experiments. Results showed exceptional affinity for adsorption of acid red 70 dye due to the charge-induced adsorption aided by quaternary ammonium groups. A high adsorbed percentage of 83% could be obtained at initial concentration of 70 ppm. Moreover, the adsorbed dye could be easily desorbed. Combining their ultrafast adsorption kinetics with excellent properties of high adsorption capacity and rapid adsorption/desorption rates remained during the five consecutive cycles, the DES-modified cellulose monolith has large potential for effluent treatment applications.

Stimuli-responsive hydrogels have garnered the attention of the hydrogel industry, as they are able to change their physical and chemical properties based on changing external stimuli such as pH, temperature, ionic strength, electromagnetic fields, and light. However, stimuli-responsive hydrogel applications are hindered due to their inevitable swelling and shrinkage. Bacterial cellulose (BC), a natural hydrogel with tightly packed cellulose nanofibers (CNFs) was oxidized into dialdehyde BC (DABC) and was composited with chitosan (CS), a readily available natural polymer, to develop a mechanically adaptive hydrogel composite under different pH conditions. Composites exhibit pH sensitivity by presenting higher mechanical properties under acidic conditions and lower mechanical properties under basic conditions owing to the protonation of amino groups of the chitosan chains. Osmotic pressure is built up under acidic conditions, increasing the mechanical strength of the composites. The good three-dimensional stability of composites enables them to consistently maintain their volume when exposed to acidic or basic conditions.

Hierarchical porous activated carbon (AC) materials were prepared from a composite of highly accessible carbon sources, sodium alginate and bacterial cellulose, by carbonization and KOH activation. The as-obtained carbon materials not only possessed rich oxygenated functionalities but also formed a hierarchical porous structure. The unique structures and chemical compositions of the resulting materials demonstrate good potential for use in supercapacitor electrode materials. The AC had a three-dimensional interconnected network structure consisting of sheet-like connected particles. Interestingly, the carbon material possessed high graphitization degree and good electrical conductivity. The electrochemical properties of electrodes were evaluated in a three-electrode system in 6 M KOH. Due to the synergistic effects of the rich oxygen content and the porous structure, the sample calcined at 700 °C showed a high gravimetric capacitance of 302 F/g, an excellent capacitance retention ratio of 75.2% at 10 A g−1, and good cycling stability with 93.8% capacitance retention after 10,000 cycles. The as-obtained single electrode exhibited a very high energy density of 23.7 W h kg−1, making it more interesting than commercial AC for practical applications. This study demonstrates that the utilization of abundant polymers from nature is a good route for fabricating high-performance supercapacitor electrode materials.

A polypropylene sponge with hierarchical structure was prepared from a polypropylene solution by combination of micro particle template and the phase separation technique. A simple procedure was proved to be able to fabricate a unique sponge in which both submillimeter-sized holes (≈200 μm) and small macrospores (≈10 μm) are formed. The unique structure was successfully confirmed by scanning electron microscopy measurement. In addition, the sponge showed low density, high hydrophobicity, and superoleophilicity. The sponge exhibited good compressibility, and high performance for the adsorption-release of oils. The adsorbability was proved to be improved in a large scale due to the existence of holes. Furthermore, the sponge demonstrated the ability to remove oil-in-water emulsion. Based on the properties, the present sponge has promising prospects for environmental applications in the treatment of oily water.

Three new palladium catalysts, PdCat-I, PdCat-II and PdCat-III, immobilized over heterogeneous silica support have been synthesized using different ligands attached to the palladium precursor. The ligands that have been used in this study are acetate, triphenylphosphine and chloride in PdCat-I, PdCat-II and PdCat-III, respectively. The ligands have different effect on stability of the compounds and impart different oxidation states to the metal center. The materials have been characterized by powder X-ray diffraction, nitrogen adsorption-desorption studies, transmission electron microscopy, thermal analysis, and different spectroscopic techniques. The Pd-content of the samples have been determined by ICP-AES analysis. The materials have been used as catalysts for Suzuki coupling reaction of aryl halides with phenylboronic acid under mild conditions. A comparative study has been carried out to ascertain the effect of the nature of different ligands on the outcome of the catalytic reactions. Products have been identified and estimated by 1H NMR and gas chromatography. The results show that the best yields are obtained with the catalyst containing triphenylphosphine as the ligand in methanol. Such type of work to study the effect of ligand on Suzuki coupling reaction over functionalized mesoporous silica heterogeneous catalysts have not been carried out so far.

Assembly of graphitized carbon nanowalls containing crystallites with the ideal interlayer distance was formed as a Voronoi cell structure of close-packed template nanoparticles. The assembly showed faster Li-ion intercalation and deintercalation than conventional graphite, a superhydrophobicity, which was retained even after thermal oxidation, and a high stability under electrochemical oxidative conditions.

Starch is the most abundant biomass and potential replacement of single-use packaging; however, the lack of water durability and wet strength restrict the applicability of starches. Hemiacetal/acetals cross-linked starch film have water stability, however, the film possess poor wet strength owing to lack of crystallinity. In this study, we prepared TEMPO-oxidized cellulose nanofiber (TCNF)/starch composite films by mixing different-storage-duration native tapioca starch (NTS), hydroxypropyl starch (HPS), and di-aldehyde starch (Di-aldS) with TCNF. We demonstrate that the films prepared with the stored starch pastes exhibit improved mechanical properties and wet strength owing to the synergistic effect of enhanced crystallinity and hemiacetal crosslinking. However, long-term storage of the starch pastes negatively affected their properties. Thus, improving the film properties by optimizing the starch paste storage time is an environmentally friendly and energy-conserving method. Moreover, our experimental results suggest that TCNF/HPS films prepared with the HPS paste stored for three days (~22 °C, ~25% RH) can be a potential alternative to single-use packaging films.

Activated carbons, BC-PANnp-ACs and BC-PANnp-KACs, have been synthesized from a composite (BC-PANnp) derived from bacterial cellulose (BC) and polyacrylonitrile nanoparticles (PANnp) by physical and chemical activation, respectively. Commercially available nata de coco has been used as the source of BC whereas PAN nanoparticles of ca. 100 nm have been synthesized in situ in the BC gel by emulsion polymerization which covers the nanofibers of BC. FE-SEM images confirm that hierarchical lamellar structure of BC is retained in the activated carbon frameworks. Detailed electrochemical studies carried out with the electrodes designed with the activated carbons reveal their good performance as electric double layer capacitors (EDLC) with fast response and high-speed charging and discharging. The activated carbons prepared by KOH activation have much higher specific surface area and exhibit better electrochemical properties compared to the carbon materials obtained by CO2 activation or the commercially available YP50F activated carbon derived from coconut shell. The three-dimensional network structure peculiar to BC reduces the grain boundary resistance between the carbonized PAN nanoparticles in these composites compared to PAN nanoparticles carbonized alone imparting good conductivity without the addition of a conductive agent.

Nitrogen-doped porous monolithic carbon (NDPMC) is obtained from biomass-derived activated carbon/polyacrylonitrile composite for the first time via a template-free thermally induced phase separation (TIPS) approach followed by KOH activation. The electrochemical results indicate that NDPMC possesses ultrahigh specific capacitance of 442 F g−1 at 1 A g−1, excellent rate capability with 81% retention rate from 1 to 100 A g−1 and outstanding cycling stability with 98% capacitance retention at 20 A g−1 after 5000 cycles. Furthermore, the evaluation of NDPMC on the practical symmetrical system also exhibits desired electrochemical performances. The novel composite carbon displays remarkable capacitance properties and the feasible, low-cost synthetic route demonstrates great potential for large-scale production of high-performance electrode materials for supercapacitors.

The objective of this study is to design the manner of ephrinB2 immobilized onto polyacrylamide (PAAm) hydrogels with varied elasticity and evaluate the effect of hydrogels elasticity and the immobilized manner of ephrinB2 on the Runx2 expression of human mesenchymal stem cells (hMSC). The PAAm hydrogels were prepared by the radical polymerization of acrylamide (AAm), and N , N′ -methylenebisacrylamide (BIS). By changing the BIS concentration, the elasticity of PAAm hydrogels changed from 1 to 70 kPa. For the bio-specific immobilization of ephrinB2, a chimeric protein of ephrinB2 and Fc domain was immobilized onto protein A-conjugated PAAm hydrogels by making use of the bio-specific interaction between the Fc domain and protein A. When hMSC were cultured on the ephrinB2-immobilized PAAm hydrogels with varied elasticity, the morphology of hMSC was of cuboidal shape on the PAAm hydrogels immobilized with ephrinB2 compared with non-conjugated ones, irrespective of the hydrogels elasticity. The bio-specific immobilization of ephrinB2 enhanced the level of Runx2 expression. The expression level was significantly high for the hydrogels of 3.6 and 5.9 kPa elasticity with bio-specific immobilization of ephrinB2 compared with other hydrogels with the same elasticity. The hydrogels showed a significantly down-regulated RhoA activity. It is concluded that the Runx2 expression of hMSC is synergistically influenced by the hydrogels elasticity and their immobilized manner of ephrinB2 immobilized. Statement of Significance Differentiation fate of mesenchymal stem cells (MSC) is modified by biochemical and biophysical factors, such as elasticity and signal proteins. However, there are few experiments about combinations of them. In this study, to evaluate the synergistic effect of them on cell properties of MSC, we established to design the manner of Eph signal ligand, ephrinB2, immobilized onto polyacrylamide hydrogels with varied elasticity. The gene expression level of an osteogenic maker, Runx2, was enhanced by the immobilized manner, and significantly enhanced for the hydrogels of around 4 kPa elasticity with bio-specific immobilization of ephrinB2. This is the novel report describing to demonstrate that the Runx2 expression of MSC is synergistically influenced by the hydrogels elasticity and their manner of ephrinB2 immobilized.

The fabrication of dual-doped activated carbon with a hierarchical pore structure is an effective way for the preparation of the high performance carbon-based electric double layer capacitor. Herein, nitrogen and sulfur dual-doped activated carbon (NSC) with hierarchical pore structure was obtained by directly carbonizing/activating polymer-based blend monolith. The as-obtained NSC samples exhibit a high specific surface area (1570–2550 cm2 g−1), a developed hierarchically pore structure, and have an appropriate nitrogen and sulfur content. Furthermore, originating from the synergistic effect by pore structure, heteroatom, and proper graphitized crystal structure, the optimized NSC-based electrode exhibits a high specific capacitance of 330.5 F g−1 at a current density of 0.5 A g−1, superior rate capability of 66% at 20 A g−1 and acceptable cycling stability in the three-electrode system. Meanwhile, the assembled carbon-based symmetric capacitor exhibits an acceptable energy density and a remarkable power density of 11 kW kg−1 with 6 mol L−1 KOH as the aqueous electrolyte. These results demonstrate that the as-resulting NSC could be a competitive candidate for carbon-based electrode materials, and this work would be a valuable exploration that as a facile synthetic strategy to prepared dual-doped activated carbon for electric double layer capacitor.

Activated carbon (AC)-containing porous cellulose beads (ACPBs) with a three-dimensionally interconnected porous structure and high impact strength were prepared in a single step from cellulose acetate and AC via a non-solvent-induced phase separation process at room temperature. The adsorption behavior of the ACPBs was evaluated using toluidine blue (TB) dye as a model adsorbate. The effects of initial dye concentration and contact time on the adsorption kinetics and isotherms of ACPBs were studied. The adsorption of TB by the ACPBs followed pseudo-second-order kinetics and could be expressed by the Langmuir adsorption isotherm model. ACPB adsorbed 119.1 mg/g of TB at an initial TB concentration of 101.0 mg/L and the Langmuir equation predicted that the maximum adsorption capacity of ACPBs for TB was 123.5 mg/g. ACPBs could retain original shape and around 85% of their adsorption capacity after three times recycle. Furthermore, ACPBs efficiently removed malodorous gases from gas mixtures, indicating potential for environmental applications including toxic dye and gas elimination.

Numerous biopolymer-based functional composites have been developed for medical applications. Poly(glutamic acid) (PGA) is an amino acid biopolymer that has recently attracted attention due to its biocompatibility, non-immunogenicity, and biodegradability. PGA and its composites have been studied to improve their function as medical materials. This review briefly introduces chemically and microbiologically synthesized PGA. In addition, this article provides general and advanced preparation methods for various PGA-based composites, including hydrogels, nanofibers, monoliths, and nanoparticles. Furthermore, it covers recent advances in PGA-based functional composites for medical applications, such as active antimicrobial materials as well as the use of PGA composites for vaccine adjuvants, cancer therapy, medical devices, and tissue regeneration. Anticancer agent delivery and cancer immunotherapy are included in the PGA-based cancer therapy system section. Barrier membranes and stent applications are summarized within the medical devices section. Furthermore, various tissue regeneration topics are introduced, including applications in wound healing, as well as the tissue-specific regeneration of bone, cartilage, intervertebral discs, corneas, kidneys, and neurons. In summary, this is an overview of the various challenges of using PGA and the scope of emerging research.

Water-swellable hydrogel-forming porous cellulose beads (HFPCBs) were obtained from a single-step thermal reaction between urea and sodium dihydrogen phosphate dihydrate on porous cellulose beads (PCBs). The HFPCBs maintained the interconnected porous structure of the PCBs and featured a specific surface area of 36.5 m2/g. Fourier transform infrared spectroscopy analysis indicated the introduction of cellulose phosphate carbamate into the HFPCBs. At the optimum reaction composition and time, HFPCBs showed a maximum centrifuge retention capacity of approximately 50 g/g in deionized water. The swelling behavior of the HFPCBs followed the second-order kinetics model. Despite their highly porous structure, HFPCBs had a compressive strength of several tens of kilopascal in the swollen state. To demonstrate their potential application, the swollen HFPCBs were successfully used for the germination of plant seeds.

Application of cellulose microfibers as a reinforcing agent for high-performance polyurethane composites is rarely mentioned because the inherent hydrophilicity combined with the adverse aspect ratio of the fibers cause difficulties in dispersion within and compatibility with the polymer matrix. Here, we propose a feasible approach to graft oligoethers synthesized by ring-opening polymerization in a heterogeneous reaction to the cellulose microfiber surface. The oligomers composed of ether linkages and flexible hydroxyl groups provide cellulose fibers with good dispersity in poly(propylene glycol) and potential physical and chemical cross-linking points in reaction with isocyanates to form good interfacial adhesion between the fibers and the polyurethane matrix. Consequently, the tensile properties and viscoelasticity of the oligomer-grafted cellulose-filled polyurethane composite were enhanced compared with those of the neat elastomer and composite containing pristine cellulose microfibers. This reinforcement effect is attributed to the natural stiffness of the fiber bundles and the cross-linking network generated by the oligomers grafted on the fiber surface.

Developing high value-added products from the waste materials is highly promising from the perspective of environmental protection and resource recovery. Herein, the used cigarette filter was recycled to prepare the flow reactor via a clean and facile strategy. A continuous-flow reduction method was adopted to produce the gold nanoparticles on deacetylated cigarette filter without any extra chemical modifier, reductant or surfactant. The obtained filter was applied as a continuous-flow reactor and showed a high permeability and ultrafast flow catalytic ability. The permeability coefficient of the reactor was about 1.4 × 10-10 m2. This work provided a clean method to covert the waste cigarette filter to useful flow reactor with the relatively simple steps, and the product had a potential for the fast reduction of 4-nitrophenol and dyes including methyl blue and methylene orange.

This data article provides supplementary figures to the research article entitled, “Phase separation approach to a reactive polycarbonate monolith for “click” modifications” (Xin et al., Polymer, 2015, doi:10.1016/j.polymer.2015.04.008). Here, the nitrogen adsorption/desorption isotherms of the prepared porous polycarbonate monolith are shown to classify its inner structure and calculate the specific surface area. The monoliths were modified by using the thiol-ene click chemistry and the olefin metathesis, which was examined by contact angle measurements, FT-IR, solid state 13C NMR spectroscopy as well as thermogravimetric analysis.

Treatment of infections using wound dressing integrated with multiple functions such as antibacterial activity, non-toxicity, and good mechanical properties has attracted much attention. In this study, carboxymethyl starch/polyvinyl alcohol/citric acid (CMS/PVA/CA) hydrogels containing silver nanoparticles (AgNPs) were prepared. The CMS, PVA and CA were used as polymer matrix and bio-based reducing agents for green synthesis of AgNPs. Silver nitrate (AgNO3) concentrations of 50, 100, and 150 mM were used to obtain nanocomposite hydrogels containing different AgNPs concentrations (AgNPs-50, AgNPs-100 and AgNPs-150, respectively). The minimum inhibitory concentration against E. coli and S. aureus was observed in CMS/PVA/CA hydrogels containing AgNPs-50. Uniform dispersion of AgNPs-100 in the hydrogel provided the highest storage modulus at 56.4 kPa. AgNPs-loaded hydrogels showed low toxicity to human fibroblast cells indicating good biocompatibility. Incorporation of AgNPs demonstrated an enhancement in antibacterial properties and overall mechanical properties, which makes these nanocomposite hydrogels attractive as novel wound dressing materials.

Owing to its excellent properties, polycarbonate (PC) is a suitable alternative for conventional engineering materials; however, its applications are limited by its poor wettability and adhesion with heterogeneous materials. In this study, chlorine dioxide radical (ClO2•) was used as an efficient oxidizing agent for PC oxidation by photoirradiation under mild conditions, instead of the previous physical treatment methods that used plasma, laser, ion beams, or UV ozone. During the oxidation reaction, polar groups like carboxyl, aldehyde, and hydroxyl were added to the surface of the PC films without causing surface damage. Furthermore, the surface wettability and metal adhesion of the PC films were improved after surface oxidation without change in the transmittance of the PC films. The effects of the oxidation conditions, viz. temperature and time, on the chemical composition, wettability, and surface morphology of the PC films were also investigated. The oxidation of PC films using light-activated ClO2• is an effective, clean, energy-saving treatment with potential for further modifications and applications.

The performance of cellulosic filler/polyolefin biocomposites is affected by the filler dispersion (aggregation and spatial arrangement) in the matrix. However, this mechanistic factor is generally inferred from the physical properties of the final bulk material because of the limitations of analytical techniques. Herein, we propose a simple method to quantitatively evaluate the dispersion of filler particles. To accomplish this, the cellulose component in injection-molded specimens of microcrystalline cellulose (MCC)/maleic anhydride-modified polypropylene (MAPP)/polypropylene (PP) composites was selectively fluorescently labeled with calcofluor white, and the dispersion state of tens of thousands of MCC particles observed by fluorescence microscopy was analyzed. The close-range aggregation behavior of the MCC particles can be evaluated by the area of the fluorescent particles (A), and the normality (randomness) of the spatial arrangement can be classified by the skewness of the distribution of the distances between the centroids of the particles (s). As a result, with an increase in the degree of acid modification of the added MAPP, aggregation of MCC was suppressed and the spatial arrangement became random. Both A and s were not associated with the modulus or fracture strain of the injection-molded specimens, but they were correlated with the tensile and bending strengths and water absorption behavior. This visualization method was also applied to a composite containing nanofibrillated cellulose filler (citric acid-modified cellulose nanofiber).

This study reports a new method of fabrication and application of “green” starch nanoparticles (SNPs) from local sago (Metroxylon Sagu) starch granules employing a high-pressure homogenization procedure. This approach is environmentally friendly, highly feasible, low cost and chemical-free with large-scale production capacity. In this work, SNPs' morphological, particle size and thermal properties were studied. The effects of SNPs concentration (ranging from 0 to 8% w/w) as nano-fillers in composite films’ barrier, transparency and contact angle were also investigated. Our results have shown that the fabricated SNPs exhibited excellent uniformity and spherical shapes. Addition of SNPs have demonstrated to enhance polymeric structure of nanocomposite film due to decreased water vapour permeability and increased contact angle. Sago SNPs as fillers pose an excellent prospect in green composites fabrication for material and biomedical purposes with potential application as carriers for drug delivery.

Our study focused on the preparation and characterization of biocomposite films consisting of poly(vinyl alcohol) (PVA) and green tea extract (GTE) with a small amount of glycerol as a plasticizer. Scanning electron microscopy (SEM) showed that both the surface and cross-section of the GTE-PVA biocomposite films were smooth and uniform. Incorporation of GTE could considerably alter the optical and mechanical properties of the pure PVA film. Notably, the GTE-PVA biocomposite films presented better water vapor and UV–vis light barrier properties and higher mechanical strength than the pure PVA film. The antioxidant ability of the biocomposite films was evaluated by measuring the 2,2-diphenyl-1-picrylhydrazyl radical scavenging and ferric reducing power in terms of the total phenolic content. The GTE-PVA biocomposite films showed higher antioxidant activity than the pure PVA film, and the antioxidant activity increased with increasing GTE concentration. The color of the GTE-PVA biocomposite films became yellow when the pH was lower than 6 and became dark red when the pH was higher than 6. Moreover, color variations were observed in the GTE-PVA biocomposite films by changing the pH. These results suggest that GTE-PVA composite films may be used as a promising antioxidant and visible pH-sensing food packaging materials.

Herein, improvement of the mechanical properties of epoxy resin by compositing with citric acid modified cellulose (CAC) was reported. CAC were prepared from carboxyl functionalization with citric acid to increase the adhesion between cellulose and epoxy resin. The epoxy resin composites were prepared using 2,2-bis (4-glycidyloxyphenyl) propane (BADGE) as component, 4-methylcyclohexane-1,2-dicarboxylic anhydride (MHHPA) as curing agent, and cellulose or CAC as filler. The tensile strength of cellulose/epoxy resin composites were decreased with the content of cellulose increased. On the other hand, the tensile strength of CAC/epoxy resin composites were effectively increased with the content of CAC increased. Moreover, compared with pure epoxy resins and cellulose/epoxy resin composites, the Young's modulus and the toughness of CAC/epoxy resin composites significantly increased with the presence of 10 wt% CAC. SEM images showed that cellulose agglomerated in epoxy resins, in contrast, CAC dispersed uniformly in epoxy resins, determined that the adhesion between CAC and epoxy resins were improved after introduced carboxyl groups to cellulose lead to the mechanical properties improved. CAC was also used to partly replace MHHPA to decrease the usage of toxic curing agent, and the mechanical properties of CAC/epoxy resin composites increased with lower MHHPA content. These results indicated that CAC can partially take place of the conventional curing agent in composite preparation, which may further decrease the production cost and improve the mechanical properties of product.

Aiming at more efficient use of coconut resources to achieve multi-purpose goals, this work proposes an innovative composite for capacitive deionization (CDI) electrode in desalination applications when using coconut shell-derived activated Carbon (AC) as a matrix into which a certain amount of carbon nanotubes (CNTs) is incorporated. The electrochemical studies show that the optimized 9mAC:1CNTs electrode with a surface area of 630 m2/g has a specific capacitance of 90.2 F/g (at scan rate of 20 mV/s), salt adsorption capacity (SAC) of 14.1 mg/g at 1.0 V. SAC value is retained as high as 95.7% after 100 adsorption–desorption cycles at 1.0/0 V, showing a good cyclic stability of the electrode composites. Moreover, a calculated specific energy consumption (SEC) value of 0.312 kW h/m3 was quite low compared with other CDI electrodes reported in literature. Briefly, the present study indicates that AC-CNTs composite can serve as promising CDI electrode materials for desalination application.

We prepared a cellulose nanofiber reinforced retrograded starch film that had adequate mechanical properties and water durability. Non-retrograded tapioca starch (NRS) and retrograded tapioca starch (RS) were blended with TEMPO-oxidized cellulose nanofiber (TCNF) in different weight ratios. Subsequently, the suspensions were cast into films using a solution casting method. It was demonstrated that TCNF/RS films exhibited reduced swelling in water and enhanced mechanical strength compared to TCNF/NRS films. X-ray diffraction confirmed the improvement in crystallinity with the introduction of retrograded starch and the contact angle test showed that retrograded starch blended films possessed high water resistance. These results suggested that retrograded starch blended TCNF films (TCNF/RS) have the potential to replace single-use petrochemical plastic packaging film.

Silica monoliths with a continuous porous structure have received much attention in biomedical and environmental applications owing to their high-performance separation/adsorption behaviors. However, it is difficult to maintain a porous structure in silica monoliths because their synthesis often involves complicated phase separation in sol-gel reactions. Herein, for the first time, we used an ecofriendly cellulose material as a template to prepare a hydrophilic and hierarchically porous silica monolith. The cellulose monolith template was prepared from cellulose acetate by a thermally induced phase separation method. The silica was then prepared in the presence of the cellulose monolith by a typical sol-gel reaction of tetraethyl orthosilicate (TEOS) to form the composite monolith, which was converted to the silica monolith by burning in air to remove the cellulose monolith. Owing to the hierarchically porous structure of the cellulose monolith template, the obtained silica monolith showed a similar hierarchically porous structure, as confirmed by scanning electron microscopy and nitrogen adsorption-desorption analyses. The pore structure could be controlled by changing the fabrication parameters, such as the kind of cellulose monolith and TEOS concentration. The surface-modified silica monolith was developed for further applications.

The lack of mechanical strength and toughness of hydrogels usually limits their application in biomedical and industrial fields. Herein, we prepared a composite hydrogel in which supramolecular bonding of an inclusion complex, between β-cyclodextrin (β-CD) as a host molecule and adamantane (Ad) as a guest molecule, was introduced into cellulose fiber/polymer matrix interface to improve the mechanical strength and toughness. Ad was chemically immobilized on the surface of the cellulose fiber. The composite gels were prepared via copolymerization of β-CD acrylamide monomer and N,N-dimethylacrylamide in the presence of Ad-modified cellulose fiber. Ad-modified cellulose acted as both the reinforcing material and the supramolecular cross-linker of the hydrogel. The mechanical strength and toughness of the composite gels were enhanced because of the interfacial host–guest interaction between the fiber and the matrix.

Single-use plastic become a post-consumer waste and create a big problem for the society and the environment. Polysaccharides are the potential replacement of single-use plastics, however lack of mechanical strength and water durability restrict their applications. In this study, we prepared a cellulose nanofiber reinforced starch membrane, which had adequate mechanical strength and durability in water. TEMPO-oxidized cellulose nanofiber (TCNF) was blended with three different types of modified starch: hydroxypropyl starch (HPS), acetyl starch (AS) and acetyl oxidized starch (AOS), respectively. It was demonstrated that the TCNF/starch membrane exhibited reduced swelling in water and enhanced mechanical strength in wet condition compared to TCNF or starch membrane because hemiacetal bonding was formed between TCNF and starch. TCNF/HPS membrane showed the highest wet tensile modulus (7 MPa) with the minimum swelling in water. Therefore, the TCNF reinforced HPS membranes may be served as potential substitutes for petrochemical plastic packaging.

As the most extensively researched thermoplastic aliphatic polyester, poly (lactic acid) (PLA) derived from renewable resources has shown it tremendous potential at replacing the petroleum-based polymers in many fields. The greatest challenge hindering the use of PLA is considered as its poor toughness. In terms of reproducible processes and products, cellulose has been applied to the PLA matrix as reinforcing fillers but the poor compatibility due to the inherent hydrophilicity of cellulose and hydrophobic nature of PLA is troubling. To solve this issue, we carried out an effective water-based method to render the cellulose surface with high carboxylic group content through the esterification of hydroxyl groups with citric acid in a solid phase reaction to strengthen the hydrogen bonding interaction with PLA. Consequently, the modified cellulose showed good dispersion in PLA matrix. The resulting flexural properties of PLA composites incorporated by the citric acid-modified cellulose and its fibrillated form as fillers were improved compared to those of the pristine PLA resin. The potential nucleating function of the modified cellulose was discussed and the filler proportion in the composite was optimized. Because of the well-established processing technique, we believe that citric acid-modified cellulose has an immense potential as a sustainable and cost-effective reinforcing filler for PLA, as a representative of bio-based polyesters.

The facile fabrication of an elastic monolithic material with a three-dimensional interconnected structure from plastics is still a challenging work. In this study, we report the fabrication of a highly elastic and macroporous monolith from a maleic anhydride (MAH)-grafted polypropylene (PP-g-MAH), which is a low-cost raw material. Simple cooling a PP-g-MAH solution in a mixed solvent of decalin and N-methyl-2-pyrrolidone forms a porous physical gel. A monolith was obtained upon exchanging the embedded solvent molecules with acetone. The monolith shows a fibrous network structure with tunable average pore sizes from sub-1 to 10 μm. In addition, the monolith exhibits a good elasticity with the ability to sustain a stress of 600 kPa at a strain of 30% and recover almost completely to the initial state when the stress is removed. Moreover, the monolith demonstrates high hydrophobicity (a water contact angle of 132°) and super oleophilicity. Based on the above superior characterizations of the monolith, we further proved that it is a good substrate for oil/water separation.

This research examined the performance of poly(lactic acid) (PLA) by the addition of cellulose nanofiber (CNF) as a filler. CNF produced by green fibrillation method without any chemical pre-treatment had advantages in low cost and time saving, which can produce bulky CNF in a short period compared with traditional methods such as acid dialysis and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidation. It was demonstrated that modification on the hydroxyl group of cellulose into acetyl group changed the compatibility of CNF with PLA. Acetylated cellulose nanofiber (ACNF) and PLA formed smooth surface composite films with good transparency and mechanical properties. Moreover, the tensile strength of neat PLA film was improved by 25% when 1 wt% of ACNF was used as the filler. Furthermore, without lowering the thermal stability of PLA, composite films of PLA/ACNF exhibited higher hydrophobicity as high as 85.9° compared with that of neat PLA film with 70.2° contact angle.

A new and simple method was developed for fabricating palladium nanoparticles (PdNPs) captured in a mesoporous monolith based on thermally induced phase separation (TIPS) method. XRD result confirmed the formation of PdNPs inside the monolith. TEM image showed that most of the captured PdNPs were in the diameter range from 5 nm to 10 nm. The monolith had relatively high specific surface area and uniform mesopore structure. To measure its catalytic efficiency, the crosslinked monolith was applied to a heterogeneous Suzuki–Miyaura reaction of aryl halide and aryl boronic acid in a water/ethanol mixture. The monolith exhibited both high catalytic performance and excellent stability for repeated use.

A new polycarbonate monolith carrying allyl groups has been introduced. The monolith was fabricated via the phase separation induced by adding cyclohexane to a solution of the polymer in chloroform. Cross-sectional analysis of the monolith was performed by scanning electron microscopy that unveiled a three-dimensionally networked porous structure inside the monolith. As a result of nitrogen adsorption/desorption experiments, the specific surface area of the monolith was calculated to be 145 m 2 /g with the Brunauer Emmett Teller equation. The allyl groups of the monolith were subjected to a thiol-ene click reaction with 2-mercaptoethanol and an olefin metathesis with a Grubbs catalyst. With the porous structure largely maintained, the click reaction attained high conversions and the metathesis internally crosslinked the monolith to the degree that confers solvent resistance. These results qualify the present monolith as a versatile platform for chemical transformations into a wide range of functional monoliths.

Oxidative stress caused by uncontrolled production of reactive oxygen species (ROS) has been linked to the initiation and progression of some diseases. Therefore, the use of antioxidants capable of scavenging ROS has attracted growing interest. We recently reported antioxidant micelles having catechol moieties, a structural motif found among natural antioxidants. These micelles showed a strong inhibitory effect in ROS-mediated angiogenesis as compared to the small catecholic compound dopamine. Here, we aim to explain this interesting function of the micelles by correlating the effects of self-assembled structures on the auto-oxidation stability and anti-angiogenic activity. The micelles were prepared from a hydrophilic poly( N -acryloyl morpholine) and a hydrophobic catechol-bearing block with different catechol content. The micelles with higher catechol content formed stable spherical micelles and showed increased stability against auto-oxidation, while micellization did not affect the redox potential of catechol moieties. Furthermore, the micelles with higher catechol content showed a stronger anti-angiogenic activity.

We developed a bio-based shape memory polymer with dynamically crosslinked network structure from trans-1,4-polyisoprene (TPI) derived from Eucommia ulmoides Oliver. Grafting of maleic anhydride onto TPI was performed in 1,2-dichlorobenzene, and the subsequent hydrolysis gave maleated trans-1,4-polyisoprene (MTPI). Increasing trend of the grafted maleic moiety was observed with increasing the concentration of maleic anhydride in the grafting reaction. With increase in maleic content, the glass transition temperature (Tg) of the resulting polymer increased, whereas the crystallinity decreased. The maximum stress of the MTPI with carboxylates was larger than that of the protonated MTPI. Above the melting temperature, the Young's modulus of MTPI with carboxylates was higher than that of neat TPI and the protonated MTPI, due to dynamically crosslinked network structure. Furthermore, the MTPI with 1% carboxylate content exhibited excellent shape memory-recovery properties, exploiting the combination of the physical crosslinking and the melting of the crystal. The resulting materials are expected to contribute to the development of bio-based intelligent materials.