The sulfate groups in agar structure played a good role in the formation of fiber.However,commercially available agar is usually extracted from red algae by alkali treatment to decrease the content of sulfate group fo...The sulfate groups in agar structure played a good role in the formation of fiber.However,commercially available agar is usually extracted from red algae by alkali treatment to decrease the content of sulfate group for the purpose of high gel strength.In this paper,an alkali-free method of agar extraction from Gracilaria lemaneiformis was proposed for the wet-spinning purpose.This method is environmentally friendly,reduces the extraction steps,saves energy,and reduces the production cost of agar fiber.The improved agar preparation process not only has higher agar yield,but also has higher molecular weight and sulfate group content,which is beneficial to the preparation and forming of fiber and makes the fiber have higher mechanical strength and elongation.Therefore,this extraction technology has broad application prospect in the textile field.展开更多
Based on aluminum sulfate,a fluorine-free and alkali-free liquid accelerator(FF-AF-A)was prepared in this study.The setting time and compressive strength of three cement types with different FF-AF-A dosages were fully...Based on aluminum sulfate,a fluorine-free and alkali-free liquid accelerator(FF-AF-A)was prepared in this study.The setting time and compressive strength of three cement types with different FF-AF-A dosages were fully investigated.The compatibility of the FF-AF-A with the superplasticizers were also investigated,and the early hydration behavior and morphology of the hydration products of reference cement paste with the FF-AF-A were explored by hydration heat,X-ray diffractometry(XRD),and scanning electron microscopy(SEM).Test results indicated that adding the FF-AF-A at 8 wt%of the cement weight resulted in 2 min 35 s initial setting time and 6 min 30 s final setting time.The 1-day compressive strength of the cement mortar with 8 wt%of FF-AF-A reached 13.5 MPa,which represents an increase of 35%as compared to the strength of cement mortar without the FF-AF-A,and the 28-day compressive strength ratio was 119%.In addition,the FF-AF-A also showed good compatibility with different superplasticizer dosages.The results show that,when the FF-AF-A was added to the cement paste,it promoted the formation of ettringite crystals due to the aluminum ions(Al^(3+))and sulfate ions(SO_(4)^(2-))reacted with gypsum in the cement,as well as promoted the hydration of tricalcium aluminate(C_(3)A)and tricalcium silicate(C3S)leading to the overall structure becomes more compact.As a consequence,the hydration heat rate of the cement sharply increased,the cement paste setting time is shortened,and the compressive strength of cement mortar is improved.展开更多
In order to improve the mechanical properties of SiO_2 aerogel-glass fiber composites, effects of different solvents(cyclohexane, n-hexane, ethanol, acetone) and different dispersing modes(planetary ball milling, ultr...In order to improve the mechanical properties of SiO_2 aerogel-glass fiber composites, effects of different solvents(cyclohexane, n-hexane, ethanol, acetone) and different dispersing modes(planetary ball milling, ultrasonic dispersion and mechanical stirring) and dispersing duration(10-40 min) on the dispersion of chopped alkali-free glass fiber bundles were studied to determine the best dispersion process. On this basis, the materials were batched according to the mass fraction of SiO_2 aerogel powder to chopped alkali free glass fiber bundles of 90:10, and a certain amount of zinc oxide light-screening agent and phenolic resin binder were added. SiO_2 aerogel glass fiber composite specimens were prepared by direct adding chopped alkali free glass fiber bundles and pre-dispersed chopped alkali free glass fiber bundles, respectively. The cold crushing strength and the thermal conductivity at different surface temperatures(300, 400, 500 and 600 ℃, respectively)of the specimens were measured. The results show that:(1) the optimum dispersion process of chopped alkali-free glass fiber bundles is using ethanol as solvent and mechanical stirring for 30 min;(2) pre-dispersion of chopped alkali-free glass fiber bundles has little effect on the thermal conductivity of SiO_2 aerogel-glass fiber composites but can improve the cold crushing strength.展开更多
Over the past two decades, the CICECO-hub scientists have devoted substantial efforts to advancing bioactiveinorganic materials based on calcium phosphates and alkali-free bioactive glasses. A key focus has been thede...Over the past two decades, the CICECO-hub scientists have devoted substantial efforts to advancing bioactiveinorganic materials based on calcium phosphates and alkali-free bioactive glasses. A key focus has been thedeliberate incorporation of therapeutic ions like Mg, Sr, Zn, Mn, or Ga to enhance osteointegration and vascularization,confer antioxidant properties, and impart antimicrobial effects, marking significant contributions tothe field of biomaterials and bone tissue engineering. Such an approach is expected to circumvent the uncertaintiesposed by methods relying on growth factors, such as bone morphogenetic proteins, parathyroidhormone, and platelet-rich plasma, along with their associated high costs and potential adverse side effects. Thiscomprehensive overview of CICECO-hub’s significant contributions to the forefront inorganic biomaterials acrossall research aspects and dimensionalities (powders, granules, thin films, bulk materials, and porous structures),follows a unified approach rooted in a cohesive conceptual framework, including synthesis, characterization, andtesting protocols. Tangible outcomes [injectable cements, durable implant coatings, and bone graft substitutes(scaffolds) featuring customized porous architectures for implant fixation, osteointegration, accelerated boneregeneration in critical-sized bone defects] were achieved. The manuscript showcases specific biofunctionalexamples of successful biomedical applications and effective translations to the market of bone grafts foradvanced therapies.展开更多
基金supported by the Program of National Natural Science Foundation of China(52173037)Natural Science Foundation of Shandong Province(ZR2020ME061)+2 种基金Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(IRT14R30)State Key Laboratory of Bio-Fibers and Eco-Textiles of Qingdao University(ZFT201810,ZKT17)Yunnan Expert Workstation Project(202105AF150061).
文摘The sulfate groups in agar structure played a good role in the formation of fiber.However,commercially available agar is usually extracted from red algae by alkali treatment to decrease the content of sulfate group for the purpose of high gel strength.In this paper,an alkali-free method of agar extraction from Gracilaria lemaneiformis was proposed for the wet-spinning purpose.This method is environmentally friendly,reduces the extraction steps,saves energy,and reduces the production cost of agar fiber.The improved agar preparation process not only has higher agar yield,but also has higher molecular weight and sulfate group content,which is beneficial to the preparation and forming of fiber and makes the fiber have higher mechanical strength and elongation.Therefore,this extraction technology has broad application prospect in the textile field.
基金grateful funding provided by National Key Research and Development Program of China(Project 2019YFC1906202)Guangxi Key Research and Development Plan(Guike AB19259008)Major Science and Technology Special Project of Guangxi Province(Guike AA18242007-3).
文摘Based on aluminum sulfate,a fluorine-free and alkali-free liquid accelerator(FF-AF-A)was prepared in this study.The setting time and compressive strength of three cement types with different FF-AF-A dosages were fully investigated.The compatibility of the FF-AF-A with the superplasticizers were also investigated,and the early hydration behavior and morphology of the hydration products of reference cement paste with the FF-AF-A were explored by hydration heat,X-ray diffractometry(XRD),and scanning electron microscopy(SEM).Test results indicated that adding the FF-AF-A at 8 wt%of the cement weight resulted in 2 min 35 s initial setting time and 6 min 30 s final setting time.The 1-day compressive strength of the cement mortar with 8 wt%of FF-AF-A reached 13.5 MPa,which represents an increase of 35%as compared to the strength of cement mortar without the FF-AF-A,and the 28-day compressive strength ratio was 119%.In addition,the FF-AF-A also showed good compatibility with different superplasticizer dosages.The results show that,when the FF-AF-A was added to the cement paste,it promoted the formation of ettringite crystals due to the aluminum ions(Al^(3+))and sulfate ions(SO_(4)^(2-))reacted with gypsum in the cement,as well as promoted the hydration of tricalcium aluminate(C_(3)A)and tricalcium silicate(C3S)leading to the overall structure becomes more compact.As a consequence,the hydration heat rate of the cement sharply increased,the cement paste setting time is shortened,and the compressive strength of cement mortar is improved.
基金financial supports from the National Key R&D Program of China (2016YFB0601301 and 2018YFB0605904)The National Natural Science Foundation of China (51672256)Henan Science and Technology Research Program (162102210343)
文摘In order to improve the mechanical properties of SiO_2 aerogel-glass fiber composites, effects of different solvents(cyclohexane, n-hexane, ethanol, acetone) and different dispersing modes(planetary ball milling, ultrasonic dispersion and mechanical stirring) and dispersing duration(10-40 min) on the dispersion of chopped alkali-free glass fiber bundles were studied to determine the best dispersion process. On this basis, the materials were batched according to the mass fraction of SiO_2 aerogel powder to chopped alkali free glass fiber bundles of 90:10, and a certain amount of zinc oxide light-screening agent and phenolic resin binder were added. SiO_2 aerogel glass fiber composite specimens were prepared by direct adding chopped alkali free glass fiber bundles and pre-dispersed chopped alkali free glass fiber bundles, respectively. The cold crushing strength and the thermal conductivity at different surface temperatures(300, 400, 500 and 600 ℃, respectively)of the specimens were measured. The results show that:(1) the optimum dispersion process of chopped alkali-free glass fiber bundles is using ethanol as solvent and mechanical stirring for 30 min;(2) pre-dispersion of chopped alkali-free glass fiber bundles has little effect on the thermal conductivity of SiO_2 aerogel-glass fiber composites but can improve the cold crushing strength.
基金the project No.2021/43/P/ST7/02418 cofunded by the National Science Centre and the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 945339JMFF,RB,PG gratefully acknowledge the financial support provided by the Polish National Science Centre for the POLONEZ BIS 1“BAGBONE”,Project no.536651. JMFF would like to thank all the national and international research collaborators for their valuable contributions,especially for the papers covered in this review article+2 种基金the scope of the project CICECOAveiro Institute of Materials,UIDB/50011/2020,UIDP/50011/2020&LA/P/0006/2020,financed by national funds through the FCT/MCTES(PIDDAC)the Department of Health Research–Indian Council of Medical Research[DHR-ICMR]India[Reference:R. 11013/28/2021-GIA/HR dated November 25,2021]is recognized by SK and MA. GES and ACP are thankful to the Core Program of the National Institute of Materials Physics within the National Research Development and Innovation Plan 2022–2027,carried out with the support of the Romanian Ministry of Research,Innovation and Digitalization under the project PC2-PN23080101.
文摘Over the past two decades, the CICECO-hub scientists have devoted substantial efforts to advancing bioactiveinorganic materials based on calcium phosphates and alkali-free bioactive glasses. A key focus has been thedeliberate incorporation of therapeutic ions like Mg, Sr, Zn, Mn, or Ga to enhance osteointegration and vascularization,confer antioxidant properties, and impart antimicrobial effects, marking significant contributions tothe field of biomaterials and bone tissue engineering. Such an approach is expected to circumvent the uncertaintiesposed by methods relying on growth factors, such as bone morphogenetic proteins, parathyroidhormone, and platelet-rich plasma, along with their associated high costs and potential adverse side effects. Thiscomprehensive overview of CICECO-hub’s significant contributions to the forefront inorganic biomaterials acrossall research aspects and dimensionalities (powders, granules, thin films, bulk materials, and porous structures),follows a unified approach rooted in a cohesive conceptual framework, including synthesis, characterization, andtesting protocols. Tangible outcomes [injectable cements, durable implant coatings, and bone graft substitutes(scaffolds) featuring customized porous architectures for implant fixation, osteointegration, accelerated boneregeneration in critical-sized bone defects] were achieved. The manuscript showcases specific biofunctionalexamples of successful biomedical applications and effective translations to the market of bone grafts foradvanced therapies.
