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1.
J Mol Graph Model ; 126: 108650, 2024 01.
Article in English | MEDLINE | ID: mdl-37871455

ABSTRACT

While surfactants are widely used in phosphogypsum, their interactions with the phosphogypsum-water interface remain unclear. This study investigates the impact of three types of surfactants, namely polycarboxylate-based surfactant (PCE-TPEG), naphthalene-based surfactant (NS), and melamine-based surfactant (MS), on the performance of phosphorus building gypsum (PBG). Additionally, a nanoscale model of the PBG-surfactant-water interface is constructed using molecular dynamics to elucidate the mechanisms underlying the interaction between different surfactants and PBG at multiple scales. The results demonstrate that all surfactants enhance the mechanical properties of PBG. PCE-TPEG exhibits the most pronounced improvement. In the model, PCE-TPEG molecules likely undergo comb-like adsorption, while NS and MS molecules tend to adsorb on both ends of the crystal plane. Changes in the potential difference between CaSO4·2H2O and H2O, as well as between CaSO4·2H2O and the surfactant, play a crucial role in adsorption. PCE-TPEG, NS, and MS molecules tend to spread horizontally in a vacuum state. With the addition of water molecules, they transition to spatial adsorption. Ca2+ easily interacts with -COO- and -SO3- groups, leading to reduced migration and flexibility of the main chain. The adsorption process of surfactants at the gypsum-water interface occurs spontaneously and Electrostatic forces are the main driving factor. This study contributes to a more comprehensive understanding on the behaviour of the phosphorus building gypsum/surfactant composites.


Subject(s)
Calcium Sulfate , Surface-Active Agents , Surface-Active Agents/chemistry , Molecular Dynamics Simulation , Water/chemistry , Phosphorus
2.
Chemosphere ; 342: 140184, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37716559

ABSTRACT

A novel approach for improving the flame retardancy, smoke suppression and mechanical properties of epoxy resins (EPs) has been proposed by incorporating functionalized hollow mesoporous silica microcapsules (SHP) loaded with phosphorous silane flame retardants (SCA) and coated with polydopamine (PDA) and transition metals. The proposed approach involves a multi-level structure that combines several mechanisms to enhance the flame-retardant properties of EP. The physical barrier provided by silica serves to impede heat and mass transfer during combustion, while the catalytic carbonization effect of phosphorus and transition metals promotes the formation of a protective char layer, which acts as a barrier to further flame propagation. Incorporating a low loading amount of 3 wt% SHP into the epoxy matrix resulted in EP/SHP-3 composites with significantly improved flame retardancy, as evidenced by a limiting oxygen index of 31.5% and a V-1 rating, in contrast to the values obtained for unmodified EP, which were 23.8% and no rating, respectively. In addition, cone calorimeter test (CCT) results indicated that the total heat release, peak heat release rate and total smoke production of EP/SHP-3 decreased by 18.2%, 25.2% and 18.4%, respectively. Moreover, the improved interfacial compatibility facilitated by polydopamine assists in the dispersion and compatibility of the SHP with the epoxy matrix, leading to better mechanical properties. Herein, the addition of 1 wt% SHP to EP significantly improved its mechanical performance, with a 16.7% increase in tensile strength and a 19.2% increase in impact strength. The design of the multi-level structural approach has the potential to provide new ideas for the simultaneous improvement of fire safety as well as mechanical properties of polymers.


Subject(s)
Epoxy Resins , Flame Retardants , Silicon Dioxide , Capsules , Catalysis , Phosphorus
3.
J Environ Manage ; 344: 118616, 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37478718

ABSTRACT

Repeated red mud (RM) stockpile accidents have sounded an alarm that a healthy alumina industry requires secure RM disposal. Unfortunately, the flawed mechanical properties of RM-based alkali-activated materials (RM-AAM) with bulk RM incorporation have impeded the ideal large-volume, low-risk utilization of RM and the provision of sustainable binders for communities. By reviewing a wide range of studies, this work provides insights into establishing a mature synthesis technique for optimizing the mechanical properties of RM-AAM. Brief evaluations of the nature and the current RM-AAM synthesis systems were conducted. The following emphasis is on addressing the influence characteristics and mechanisms of the known RM-AAM synthesis factors, including RM pre-activation, precursor composition, alkali activator property, preparation process treatment, and curing regime, on the mechanical properties of RM-AAM. Further optimization suggestions on each aspect of the synthesis process and the final complete set of synthesis technology that could best enhance the mechanical properties of RM-AAM were proposed. The general limitations of current research on developing a mature RM-AAM synthesis technique were identified, along with possible solutions.


Subject(s)
Alkalies , Aluminum Oxide
4.
Anim Nutr ; 13: 411-425, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37388462

ABSTRACT

This study explored the effects of uterine inflammation on eggshell mineralization, ultrastructure and mechanical properties in laying hens modified by a lipopolysaccharide (LPS) challenge or dietary essential oil (EO) addition. In trial 1, a total of 72 Hy-line Brown layers at 36 wk of age were randomly assigned to 3 treatment groups (n = 8), where they were intravenously injected with phosphate buffered saline, LPS at 1 mg/kg body weight, or LPS 3 times at 24-h intervals. In trial 2, a total of 288 Hy-line Brown layers at 60 wk of age were randomly divided into 4 groups (n = 8), where they were fed basal diets supplemented with EO at 0, 50, 100 and 200 mg/kg for 12 wk. A uterine inflammation model was constructed with LPS treatment, indicated by the elevated expression of IL-1ß and TNF-α (P < 0.05) and lymphocyte infiltration. Uterine inflammation caused remarkable decreases in eggshell thickness and mechanical properties with structure deteriorations (P < 0.05). Uterine inflammation stimulated the expression of matrix proteins ovotransferrin (TF) and ovalbumin (OVAL), while depressing the mRNA levels of calbindin-1 (CALB1) and osteopontin in uterine mucosa (P < 0.05). In contrast, EO addition alleviated uterine inflammation, evidenced by depressed levels of IL-1ß and IL-6 (P < 0.05). There was a significant elevation in shell thickness and breaking strength following EO intervention (P < 0.05), and these effects were maximized at addition of 100 mg/kg. Further, EO improved shell ultrastructure including more early fusion, less type B mammillae, and increased effective thickness (P < 0.05). The alleviated inflammation decreased the expression of OVAL and TF, whereas ion transport genes like CALB1 and solute carrier family 26 member 9 were upregulated (P < 0.05). Our findings suggest that inflammatory status can impact uterine functions in calcium transport and the synthesis of matrix proteins especially such as OVAL and TF, which in turn modulates calcium precipitation and ultrastructure formation, thereby determining eggshell mechanical properties. These findings provide a novel insight into the uterine inflammation-mediated modifications of eggshell quality.

5.
Carbohydr Polym ; 314: 120882, 2023 Aug 15.
Article in English | MEDLINE | ID: mdl-37173036

ABSTRACT

Food freshness monitoring is vital to ensure food safety. Recently, packaging materials incorporating pH-sensitive films have been employed to monitor the freshness of food products in real time. The film-forming matrix of the pH-sensitive film is essential to maintain the desired physicochemical functions of the packaging. Conventional film-forming matrices, such as polyvinyl alcohol (PVA), have drawbacks of low water resistance, poor mechanical properties, and weak antioxidant ability. In this study, we successfully synthesise PVA/riclin (P/R) biodegradable polymer films to overcome these limitations. The films feature riclin, an agrobacterium-derived exopolysaccharide. The uniformly dispersed riclin conferred outstanding antioxidant activity to the PVA film and significantly improved its tensile strength and barrier properties by forming hydrogen bonds. Purple sweet potato anthocyanin (PSPA) was used as a pH indicator. The intelligent film with added PSPA provided robust surveillance of volatile ammonia and changed its color within 30 s in the pH range of 2-12. This multifunctional colorimetric film also engendered discernible color changes when the quality of shrimp deteriorated, demonstrating its great potential as an intelligent packaging material to monitor food freshness.


Subject(s)
Anthocyanins , Colorimetry , Anthocyanins/chemistry , Food Packaging , Polyvinyl Alcohol/chemistry , Plant Extracts/chemistry , Hydrogen-Ion Concentration
6.
Materials (Basel) ; 16(8)2023 Apr 07.
Article in English | MEDLINE | ID: mdl-37109782

ABSTRACT

In this study, commercial AZ31B magnesium alloy was used to compare the differences between the microstructure, texture, and mechanical properties of conventional solidification (as homogenized AZ31) and rapid solidification (as RS AZ31). The results demonstrate that a rapidly solidified microstructure leads to better performance after hot extrusion with a medium extrusion rate (6 m/min) and extrusion temperature (250 °C). The average grain size of as-homogenized AZ31 extruded rod is 100 µm after annealing and 4.6 µm after extrusion, respectively, but that of the as-RS AZ31 extruded rod is only about 5 µm and 1.1 µm, correspondingly. The as-RS AZ31 extruded rod attains a high average yield strength of 289.6 MPa, which is superior to the as-homogenized AZ31 extruded rod, and is improved by 81.3% in comparison. The as-RS AZ31 extruded rod shows a more random crystallographic orientation and has an unconventional weak texture component in <112¯1>/<202¯1> direction, which has not been reported yet, while the as-homogenized AZ31 extruded rod has an expected texture with prismatic <101¯0>/<1¯21¯0>//ED.

7.
Food Chem ; 420: 135649, 2023 Sep 15.
Article in English | MEDLINE | ID: mdl-37080111

ABSTRACT

Apple cider juice yield at harvest and after 15 and 30 days of storage durations was studied by analyzing the mechanical properties of fresh and plasmolyzed flesh, water distribution, cell wall polysaccharide composition and organization of the apples; in this study, the apple varieties used were Avrolles, Douce coetligne, Douce moen, Judor, Petit jaune. Juice yield mainly depended on the apple variety and the storage duration. Cellulose organization and cell wall pectin hydration were affected by ripening and are related to fruit firmness. Flesh viscoelastic mechanical properties were not general indications of juice yields. However, these properties helped distinguish the varieties according to flesh damage caused by ice crystals upon freezing. Cell encapsulation of the juice in the flesh contributed to lower yields. The apple variety and harvesting mode are recommended as a means to better control juice yield variations.


Subject(s)
Malus , Malus/chemistry , Polysaccharides/analysis , Pectins/analysis , Cellulose/analysis , Fruit/chemistry
8.
Carbohydr Polym ; 305: 120577, 2023 Apr 01.
Article in English | MEDLINE | ID: mdl-36737210

ABSTRACT

With the dramatically increased environmental problems, the rational design of sustainable polymers from renewable feedstocks opens new avenues to reduce the huge pollution impact. The major challenge for sustainable polymers is the decreased mechanical performance compared to that of petroleum-based materials. In this work, fully biobased sustainable elastomers were developed by integrating renewable chitin, lignin, and plant oil into one macromolecule, in which chitin was chosen as the rigid backbone, while a lignin-derived monomer vanillin acrylate (VA) and a plant oil-based monomer lauryl acrylate (LA) were selected as the hard and soft segments for the grafted side chains. A series of Chitin-graft-poly(vanillin acrylate-co-lauryl acrylate) (Chitin-g-P(VA-co-LA)) copolymers with varied feed ratios and chitin contents were synthesized by using reversible addition-fragmentation chain transfer (RAFT) polymerization as an effective grafting strategy. In addition, a dynamic cross-linked network was incorporated via Schiff-base reaction to improve the macroscopic behavior of such kind of chitin graft elastomers. These sustainable elastomers are mechanically strong and show excellent reprocessablity, as well as outstanding UV-blocking property. This strategy is versatile and can inspire the further development of fully biobased sustainable materials from natural resources.

9.
Carbohydr Polym ; 300: 120253, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36372510

ABSTRACT

In this work, a systematic coupling study of silane coupling agent between starch and epoxidized soybean oils (ESO) was carried out. Starch was modified by 3-aminopropyl trimethoxy silane (APMS) with various contents of NaOH. The APMS-modified starch was incorporated with ESO to synthesize the bioplastics by solution casting. As demonstrated by the FTIR spectra, the hydrogen bond interactions among starch molecules were inhibited by the modification. This outcome provided higher interaction and compatibility of starch with ESO, as confirmed by FESEM. TGA showed that the thermal stability of starch decreased considerably after the silylation. In contrast, the produced bioplastics with silylated starch exhibited higher thermal stability than the control sample. Regarding the bioplastics, an obvious increase of tensile strength from 5.78 MPa to 9.29 MPa was obtained. This work suggested a simple and effective modification technique by APMS to improve compatibility of starch/ESO-based bioplastics with superior mechanical and thermal properties.


Subject(s)
Manihot , Soybean Oil , Soybean Oil/chemistry , Manihot/chemistry , Silanes , Starch/chemistry , Tensile Strength
10.
Int J Biol Macromol ; 209(Pt B): 1848-1857, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35487380

ABSTRACT

In this work, sustainable cellulose-g-poly(lauryl acrylate-co-acrylamide) [Cell-g-P(LA-co-AM)] bottlebrush copolymer elastomers derived from cellulose and plant oil were synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization. Differential scanning calorimeter (DSC) results indicate that these thermally stable Cell-g-P(LA-co-AM) bottlebrush copolymer elastomers show adjustable melting temperatures. Monotonic and cyclic tensile tests suggest that the mechanical properties, including tensile strength, extensibility, Young's modulus, and elasticity, can be conveniently controlled by changing the LA/AM feed ratio and cellulose content. In such kind of bottlebrush copolymer elastomers, the rigid cellulose backbones act as cross-linking points to provide tensile strength. The incorporated PAM segments can form additional network structure via hydrogen bonding, resulting in enhanced tensile strength but decreased extensibility when more PAM segments are introduced. This versatile strategy can promote the development of sustainable cellulose-based bottlebrush copolymer elastomers from renewable resources.


Subject(s)
Cellulose , Elastomers , Cellulose/chemistry , Elastomers/chemistry , Plant Oils , Polymerization , Polymers
11.
ACS Appl Mater Interfaces ; 14(18): 21392-21405, 2022 May 11.
Article in English | MEDLINE | ID: mdl-35476424

ABSTRACT

An imperative processing way to produce 3D printed structures with enhanced multifunctional properties is printing inks in the form of a gel-like colloidal emulsion. The surface-modified microcrystalline cellulose (MCC) is an excipient of outstanding merit as a particulate emulsifier to manufacture a stable Pickering emulsion gel. The tuning of the MCC structure by cationic antimicrobial compounds, such as ε-polylysine (ε-PL), can offer a surface activity with an antimicrobial effect. However, the MCC/ε-PL lacks the appropriate emulsifying ability due to the development of electrostatic complexes. To overcome this challenge, (i) a surface-active MCC conjugate was synthesized by a sustainable dual-grafting technique (ii) to produce a highly stable therapeutic soy-based Pickering emulsion gel (iii) for potential application in 3D printing. In this regard, the tea polyphenols were initially introduced into MCC by the free-radical grafting method to decrease the charge density of anionic MCC. Then, the antioxidative MCC-g-tea polyphenols were reacted by ε-PL to produce a dual-grafted therapeutic MCC conjugate (micro-biosurfactant), stabilizing the soy-based emulsion system. The results indicated that the dual-grafted micro-biosurfactant formed a viscoelastic and thixotropic soy-based emulsion gel with reduced droplet size and long-term stability. Besides, there was an improvement in the interfacial adsorption features of soy-protein particles after micro-biosurfactant incorporation, where the interfacial pressure and surface dilatational viscoelastic moduli were enhanced. Consequently, it was revealed that the therapeutic Pickering emulsion gel was more suitable to manufacture a well-defined 3D architecture with high resolution and retained permanent deformation after unloading (i.e., a recoverable matrix). This work established that the modification of the MCC backbone by tea polyphenols and ε-PL advances its bioactive properties and emulsifying performance, which finally obtains a soy-based 3D printed structure with noteworthy mechanical strength.


Subject(s)
Anti-Infective Agents , Polyphenols , Anti-Bacterial Agents , Anti-Infective Agents/chemistry , Cations , Cellulose , Emulsions/chemistry , Polylysine/chemistry , Polyphenols/chemistry , Printing, Three-Dimensional , Tea
12.
Chemosphere ; 291(Pt 1): 132704, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34715101

ABSTRACT

In an attempt to alleviate the harmful impact of the flammability of epoxy resin on the environment, amitrole, a herbicide, has been converted to a novel flame retardant (PBA) with lamellar morphology through organophosphorus modification. This material has been utilized to fabricate fire safe epoxy thermosets (EP). EP containing 7.5 wt% PBA undergoes quick self-extinguishment upon ignition. This blend displays a high limiting oxygen index (LOI) value of 34%. More importantly, hazardous products (heat, smoke, toxic gases including CO/CO2) released during combustion of EP, are strongly suppressed in the presence of PBA. The mechanical properties of EP-PBA blends are comparable to those of virgin EP. The tensile strength of EP containing PBA is 90% of that of unmodified EP. The flexural strength of PBA blends is somewhat greater than that for EP containing no additive. A tactful strategy for the transformation of amitrole, a potential environmental contaminant to a benign flame retardant for polymers has been developed.


Subject(s)
Flame Retardants , Herbicides , Amitrole , Epoxy Resins , Flame Retardants/toxicity , Phosphorus , Smoke
13.
Poult Sci ; 101(1): 101539, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34823167

ABSTRACT

This study evaluated dietary Zn supplementation on productive performance, eggshell quality and ultrastructure, and calcium metabolism during eggshell formation in laying ducks. A total of 360 Longyan laying ducks (45-wk) were randomly divided into 5 treatment groups with 6 replicates of 12 birds each and fed for 20 wk. The 6 treatments fed the basal diet supplemented with 0 (control), 20, 40, 80, or 160 mg Zn/kg (ZnSO4·H2O). Dietary supplemental level at 80 mg/kg increased egg production (4.3%) and mass (5.7%), and decreased FCR (2.9%) compared to the basal diet, and these indices increased quadratically with increasing Zn supplemental levels (P < 0.05). The shell breaking strength (15.8%) and fracture toughness (10.6%) were higher with the supplementation of Zn at 80 mg/kg than the basal diet, and increased quadratically with Zn supplementation (P < 0.05). Dietary supplementation of Zn at 80 mg/kg improved shell ultrastructure by increasing total (9.0%) and effective thickness (14.2%) and decreasing mammillary thickness (12.0%), and their responses were quadratic with increasing Zn levels (P < 0.05). The supplementation of Zn affected the calcium contents in plasma, tibias and ulna, ulna phosphorus content, and linear and quadratic effects were observed, and higher values were observed with 160 mg/kg Zn supplementation than control (P < 0.05). The supplemental Zn level at 80 mg/kg increased shell effective thickness in growth stage (P < 0.05), and shell calcium and phosphorus content in initial and growth stages (P < 0.05). Dietary Zn supplementation did not affect the gene expression of Ca2+ transporters in the eggshell gland, but affected the expression of HCO3- exchanger in initial and growth stage (P < 0.05). Overall, dietary Zn supplementation could improve productive performance and shell quality in laying ducks at late phase of production, and calcium metabolism and deposition were modulated by Zn influencing HCO3- secretion and thus affecting shell ultrastructure and quality. A supplemental level of 80 mg/kg Zn in the diet with a basal content of 34.0 mg/kg was optimal, and higher level (160 mg/kg) decreased shell calcium deposition by depressing its metabolism.


Subject(s)
Ducks , Egg Shell , Animals , Calcium , Chickens , Dietary Supplements , Ovum , Zinc
14.
J Colloid Interface Sci ; 609: 513-522, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34802764

ABSTRACT

Epoxy resins (EP) possessing superior flame retardancy, mechanical properties and glass transition temperature are urgently needed to meet the ever-increasing requirement of high performance for the practical application of EP. Herein, lamellar-like phosphorus-based triazole-zinc complex (Zn-PT) was firstly constructed through coordination reaction in a facile condition to address the above issue. The results revealed that Zn-PT was well dispersed in epoxy matrix, and with 3 wt% Zn-PT, the tensile strength, flexural strength and modulus of epoxy composites were remarkably increased from 71, 112 and 2982 MPa of neat epoxy resin (EP) to 80, 162 and 3482 MPa respectively. The glass transition temperature was higher than EP. Besides, the limiting oxygen index (LOI) increased to 28.3%, and UL-94V-1 level was available. Meanwhile, the cone calorimeter test (CCT) results showed that epoxy composites displayed less heat release and smoke production. Generally, this work provides a feasible strategy to prepare high-performance epoxy composites, which has the potential to satisfy the requirement of epoxy in the practical application.


Subject(s)
Epoxy Resins , Phosphorus , Hot Temperature , Triazoles , Zinc
15.
Sci Total Environ ; 798: 149262, 2021 Dec 01.
Article in English | MEDLINE | ID: mdl-34375242

ABSTRACT

The incorporation of phosphogypsum (PG) in magnesium potassium phosphate cement (MPPC) can promote the utilization of PG not only by utilising the phosphate impurity in PG, but also by immobilising the heavy metals with MPPC. This paper investigates the feasibility of the incorporation of PG in preparing MPPC. Both early age properties, including workability and setting time, and hardened properties of compressive strength and microstructure, of PG-incorporated MPPC paste were investigated, and the hydration mechanism was explored. The results indicated that the addition of PG increased the workability of MPPC and extended the setting time of MPPC. However, incorporation of 20% PG slightly reduced the compressive strength because higher PG content led to the loose microstructure. Moreover, the addition of PG did not change the formation of hydration product, while it only reduced the hydration heat. Finally, compared to PG, the concentration of leached heavy metals of MPPC with PG was significantly reduced after 28 days curing.


Subject(s)
Magnesium Compounds , Magnesium , Calcium Sulfate , Phosphates , Phosphorus
16.
Int J Biol Macromol ; 186: 328-340, 2021 Sep 01.
Article in English | MEDLINE | ID: mdl-34246680

ABSTRACT

Mechanical properties of biopolymer films can be a limitation for their application as packaging. Soybean straw crystalline nanocelluloses (NC) can act as reinforcement load to improve these material properties, and W/O/W double emulsion (DE) as encapsulating bioactive agents can contribute to produce active packaging. DE droplets were loaded with pitanga leaf (Eugenia uniflora L.) hydroethanolic extract. The mechanical, physicochemical, and barrier properties, and the microstructure of gelatin and/or chitosan films incorporated with NC or NC/DE were determined by classical methods. Film antioxidant activities were determined by ABTS and DPPH methods. The incorporation of NC/DE in gelatin and/or chitosan films (NC/DE films) changed the morphology of these films, which presented more heterogeneous air-side surfaces and cross-sections. They presented rougher topographies, notably greater resistance and stiffness, higher barrier properties to UV/Vis light and higher antioxidant activity than the NC films. Moisture content, solubility in water and water vapor permeability decreased due to the presence of DE. Overall, the NC/DE films improved all properties, when compared to the properties of NC films or those of films with only DE, from a previously published study. In spite of not having antimicrobial activity against the studied bacteria, NC/DE films did display a great antioxidant activity.


Subject(s)
Antioxidants/chemistry , Cellulose/chemistry , Chitosan/chemistry , Edible Films , Eugenia , Gelatin/chemistry , Glycine max , Nanocomposites , Nanofibers , Plant Extracts/chemistry , Antioxidants/isolation & purification , Antioxidants/pharmacology , Cellulose/isolation & purification , Drug Compounding , Emulsions , Ethanol/chemistry , Eugenia/chemistry , Nanotechnology , Oils/chemistry , Oxidation-Reduction , Plant Extracts/isolation & purification , Plant Extracts/pharmacology , Plant Leaves , Solvents/chemistry , Glycine max/chemistry , Tensile Strength , Water/chemistry
17.
J Sci Food Agric ; 101(15): 6443-6451, 2021 Dec.
Article in English | MEDLINE | ID: mdl-33990962

ABSTRACT

BACKGROUND: Different thermoplastic starch (TPS) films were prepared with or without the addition of microcrystalline cellulose (MCC) obtained via the melt-extrusion method, and then the hot-press method was used to produce environmentally friendly TPS-based film/paper composites to replace petroleum-based materials. RESULTS: The paper-plastic composites exhibited good interfacial adhesion from the scannign elctron microscopy images. It was seen that 5 wt.% MCC was added to reinforce the mechanical properties of TPS films, such that it also improved the barrier properties of MCC@TPS/paper composites and extended the path of water vapor through TPS films, which decreased the water vapor transmission rate of MCC@TPS/paper composites. TPS/paper composites and MCC@TPS/paper composites have better physical properties (i.e. smoothness, flexibility and folding resistance) than only paper. In particular, it was found that the water contact angle of MCC@TPS/paper composites and TPS/paper composites were higher than single-layer paper. Furthermore, MCC reinforced paper-plastic composites demonstrated good barrier properties which can meet the requirement of the need for lower water sensitive materials in the food packaging industry. CONCLUSION: Thermoplastic corn starch-based film/paper composites have good application properties as a potential source of bioplastic materials. © 2021 Society of Chemical Industry.


Subject(s)
Cellulose/chemistry , Food Packaging/instrumentation , Plant Extracts/chemistry , Starch/chemistry , Zea mays/chemistry , Steam , Temperature , Tensile Strength
18.
Chemosphere ; 280: 130722, 2021 Oct.
Article in English | MEDLINE | ID: mdl-33971414

ABSTRACT

Adsorption uranium [U(VI)] from U-containing radioactive wastewater (URW) is a critical strategy for solving the resource shortage and environmental pollution in pace with the sustainable development of nuclear energy. However, the URW universally exhibits acidity and contains co-existing metal ions with high concentration. Herein, the amidoximation ethylene-acrylic acid copolymer balls (EAA-AO) with aciduric and super-high mechanical property were successfully synthesized through grafting diaminomaleonitrile and further treatment of amidoximation. Significantly, the mechanical properties of EAA-AO were not affected by the grafting process and maintained super-high mechanical properties. Furthermore, the -NH2 and unreacted -CN groups in diaminomaleonitrile adjusted the pKa to make the optimal pH be 4. In addition, the microstructure of EAA-AO was transformed from the original dense to multi-layer porous structure, which promoted the mass transfer process and the contact between uranyl ions (UO22+) and internal adsorption active sites. The adsorption capacity of EAA-AO was about 1.78 times that of EAA at pH = 4, and the adsorption capacity for U(VI) was about 8.17 times that of Ba2+ with the second highest adsorption capacity. Therefore, the EAA-AO exhibited ultra-high adsorption performance (qe = 3.196 mg g-1) in the artificial radioactive wastewater, laying a good foundation for subsequent large-scale industrial adsorption of U(VI) in nuclear industrial wastewater.


Subject(s)
Uranium , Acrylates , Adsorption , Ethylenes , Porosity , Uranium/analysis , Wastewater
19.
Mater Sci Eng C Mater Biol Appl ; 118: 111447, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33255036

ABSTRACT

The numerous advantages of hydrogel make it possible to apply as dressing. However, it is challenging in designing hydrogels with desired antibacterial activity and enhanced mechanical properties at the same time. Herein, a graphene oxide/rose bengal/polyvinyl alcohol hybrid hydrogel (ß-GO/RB/PVA HD) is prepared by freezing and thawing a mixed polyvinyl alcohol (PVA) solution of rose bengal (RB) immobilized with chitosan microspheres (CM) and a modified graphene oxide network (ß-GO). The mechanical properties and light-triggered antibacterial activity of hydrogel are systematically evaluated. The ß-GO inorganic network interpenetrate into the PVA porous structure, which significantly improves the mechanical properties of hydrogel. The hyperthermia generated by ß-GO under 808 nm light irradiation combined with reactive oxygen species (ROS) produced by RB under 550 nm light irradiation give rise to excellent antibacterial activity requiring irradiation for only 10 min as demonstrated by our experiments conducted in vitro and in vivo. Meanwhile, ß-GO/RB/PVA HD exhibits outstanding biocompatibility and water-absorbing capacity. More importantly, the hybrid hydrogel can significantly accelerate bacteria-accompanied wound healing. The results demonstrated that the hybrid hydrogel could be a promising wound dressing for preventing bacterial infection.


Subject(s)
Polyvinyl Alcohol , Rose Bengal , Anti-Bacterial Agents/pharmacology , Graphite , Hydrogels/pharmacology , Rose Bengal/pharmacology
20.
Biomaterials ; 268: 120553, 2021 01.
Article in English | MEDLINE | ID: mdl-33253963

ABSTRACT

Promoting bone regeneration to treat bone defects is a challenging problem in orthopedics, and developing novel biomaterials with both osteogenic and angiogenic activities is sought as a feasible solution. Here, copper-silicocarnotite [Cu-Ca5(PO4)2SiO4, Cu-CPS] was designed and fabricated. In this study, the Cu-CPS ceramics demonstrated better mechanical, osteogenic, and angiogenic properties in vitro and in vivo than pure CPS one. Particularly, CPS with 1.0 wt% CuO (1.0Cu-CPS) exhibited the best performance. Additionally, hydroxyapatite with 1.0 wt% CuO (1.0Cu-HA) was used to explore the respective effects of copper and silicon (Si). According to the in vitro results, it indicated that Cu enhanced the osteogenic activity of CPS ceramics although Si played a dominate role in the osteogenic process. Moreover, Cu could promote an early stage of angiogenesis, and the complementary effect of Si and Cu was found in the late phase. Furthermore, the in vivo results illustrated that the synergistic effect of Cu and Si improved bone and vessel regeneration during the degradation of Cu-CPS scaffolds (P < 0.05). Therefore, Cu-CPS ceramics could improve osteogenesis and angiogenesis through the simultaneous effects of Cu and Si, thus, offering a promising treatment option in orthopedic application for bone tissue regeneration.


Subject(s)
Copper , Osteogenesis , Bone Regeneration , Calcium Phosphates , Ceramics/pharmacology , Silicates/pharmacology
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