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Titanium is widely used in medical implants despite the release of heavy metal ions over long-term use. Zirconia is very close to the color of teeth; however, its biological inertness hinders bonding with bone tissue. Alkaline treatment and coatings of calcium phosphate can be used to enhance bone regeneration adjacent to dental implants. This study examined the effects of alkaline treatment, calcium phosphate coatings, and sintering, on the physical properties of implant material. Our analysis confirmed that the calcium phosphate species were octacalcium phosphate (OCP). The sintering of calcium phosphate was shown to create B-type HAP, which is highly conducive toward the differentiation of mesenchymal stem cells (MSCs) into osteoblasts for the facilitation of bone integration. Conclusions: This study demonstrated the room-temperature fabrication of dental implants with superhydrophilic surfaces to enhance biocompatibility.

This paper reports an improved traditional fiber degumming method, where sisal fibers were treated by alkali oxygen and pectinase, respectively, after the solute alkali pretreatment. To explore the influence of various factors on its degumming, efficiency of degumming through single factor and orthogonal experiments was aasessed. The results showed that pectinase/alkali-oxygen method after the first alkali treatment had a good effect on the degumming of sisal fiber, and most of the non-cellulose components such as hemicellulose, lignin and pectin had been removed. After pectinase treatment, the cellulose content and crystallinity were 71.87% and 66.29%, respectively. After alkaline oxygen treatment, the cellulose content was 77.16%, and the crystallinity was 69.09%. In terms of degumming rate, alkali oxygen treatment worked better than pectinase treatment, the degumming rate of pectinase method was about 10%, while that of alkali-oxygen method was more than 20%. In other hand, the pectinase method was much milder and had less damage to fibers. It would provide some references for the future application and development of sisal fiber.

In this work, Ce was used as the A-site element and three-dimensional ordered macroporous (3DOM) materials as the template to obtain 3DOM CeCo 0.7 Mn 0.3 O 3 catalyst via excessive impregnation method. The catalyst was subjected to acid/alkali treatment with dilute nitric acid and sodium hydroxide solutions. The results revealed that the catalysts subjected to acid/alkali treatment exhibited better structural and catalytic activity characteristics than the bulk catalyst. Specifically, the specific surface area of the catalyst treated with acid increased from 34.86 to 60.67 m 2 ·g -1 , and the relative contents of O ads and Mn 4+ species increased. Moreover, the T 90% further decreased to 174 °C. As for the catalyst treated with alkali, it exhibited a rougher surface and a wider pore size distribution, producing more lattice defects which were favorable for reaction progress. The T 90% was 183 °C, indicating that acid/alkali treatment both had a positive effect on the catalytic oxidation of toluene.

Ultraviolet (UV) ageing is one main environmental factor affecting the service performance and life of plant fiber reinforced composites. Plant fiber treatment or modification is an essential step in composite preparation to deal with the poor interfacial strength between plant fiber and thermoplastic matrix. Our previous study shows that water treatment is one green fiber treatment method and has potential industrial application. In this paper, effects of water and alkali treatment of hemp fiber on UV resistance of the reinforced polypropylene (PP) composites were studied. Hemp fiber was treated with water and alkali solution firstly, and then blended with PP, respectively. UV ageing of the PP composites was performed. Digital microscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were employed to characterize composite degradation. Water uptake and tensile tests were also conducted to deeply understand the effects of water and alkali treatment on UV ageing of the composites. The surface observation results showed that UV ageing occurs around the fiber locations on composite surface in early stage, both water and alkali treatment of fiber could retard surface whitening and cracking of the composites. After 4 weeks, carbonyl index of the composite reinforced with untreated fiber reached up to 29.3 while that of the composites reinforced with water or alkali treated fiber was only 19.6. The XRD patterns also confirmed that both water and alkali treatment have less crystallization after 8 weeks. Water uptake of composites is greatly decreased from 2.5 to 1.0% by water or alkali treatment of hemp fibers. However, either water or alkali treatment didn’t give obvious contribution to resist the deterioration of composite tensile properties. The hydrophilicity and water absorption of hemp fiber play an important role in UV degradation of composites. Water and alkali treatment could greatly decrease water absorption, which is beneficial to improve UV resistance of plant fiber reinforced composites. This study is helpful to deeply understand UV ageing mechanism and develop related anti-UV ageing technology of plant fiber reinforced composites.

The use of cellulose-based absorbing materials, such as fluff pulp, has attracted extensive attention due to the increasing demands of the hygiene products for the babies, women and seniors in a green and safe way. However, the properties of fluff pulp, mainly including the moisture adsorption and fluff-specific volume, highly depends on the aggregation structure and hydrogen bonding of the feedstock of cellulose fibers. In this study, a microwave-assisted alkali treatment was applied to improve these properties above, and the variations of the hydrogen bonding and aggregation structure of cellulose fiber under the microwave-assisted alkali treatment were investigated. The FTIR results showed that the microwave-assisted alkali treatment not only decreased the inter-molecular hydrogen bonding of inter-fibers, but also increased the intra-fibrillation of single fiber, thus improving the potential moisture adsorption and fluff-specific volume of the fluff pulp. The microwave irradiation facilitated the depolymerization and decrystallization of cellulose fiber during alkali treatment process, which can be confirmed by the decreases of the polymerization degree and crystalline index. The fluff pulp prepared from microwave-assisted alkali treated fiber exhibited higher absorption ability than that of those samples without microwave irradiation. A 10 wt% NaOH concentration in alkali treatment system was optimized to obtain a fluff pulp product with satisfactory fluff-specific volume and burst strength index. Microwave irradiation can be considered as a promising treatment method in the preparing process of cellulose based absorbing material.

Global warming, environmental changes, and other problems have been increasing in the last decade. Researchers and scholars want to safeguard life on the earth by making eco-friendly products, like natural composite materials. Natural fibre is environmentally valuable because of its biodegradable nature. However, there is a serious problem caused by the incompatibility between fibre and matrix. In this work, sugar palm fibre was combined with thermoplastic polyurethane composites after treatment with different concentrations of sodium hydroxide from 2 to 6% to enhance the compatibility between them. An extrusion machine was used to combine 30% by weight of the sugar palm fibre and 70% by weight of thermoplastic polyurethane composites. The temperature, rotation velocity, and fibre size were fixed at (180–190–200°C), 40 rpm and 250 μm respectively. The composite was characterized according to ASTM D638. The sodium hydroxide treatment of the fibre could provide a good tensile modulus of 440 MPa at 2% of NaOH, and strain of 41.6% at 6% NaOH of the composite. However, the tensile strength was decreased, where the highest amount of 5.49 MPa recorded at 6% NaOH. Meanwhile, the tensile modulus and strain of the composites are found to be much better than those of untreated ones. In contrast, the tensile strength was still not improved.

In recent years, zirconia has been a recognized implant material in clinical dentistry. In the present study, we investigated the performance of an alkali-modified ceria-stabilized tetragonal ZrO2 polycrystalline ceramic-based nanostructured zirconia/alumina composite (NANOZR) implant by assessing surface morphology and composition, wettability, bovine serum albumin adsorption rate, rat bone marrow (RBM) cell attachment, and capacity for inducing bone differentiation. NANOZR surfaces without and with alkali treatment served as the control and test groups, respectively. RBM cells were seeded in a microplate with the implant and cultured in osteogenic differentiation medium, and their differentiation was evaluated by measuring alkaline phosphatase (ALP) activity, osteocalcin (OCN) production, calcium deposition, and osteogenic gene expression. The alkali-treated NANOZR surface increased ALP activity, OCN production, calcium deposition, and osteogenesis-related gene expression in attached RBM cells. These data suggest that alkali treatment enhances the osteogenesis-inducing capacity of NANOZR implants and may therefore improve their biointegration into alveolar bone.

Dimethylol dihydroxyethylene urea (DMDHEU)-treated cotton fabrics were treated with alkali or alternatively acid followed by alkali for increasing time periods, and their effectiveness in removing the crosslinking agent was investigated by surface (X-ray photoelectron spectroscopy) analysis, bulk analysis, crease recovery angle performance and solubility in specific solvents. The cellulose yield after the chemical stripping processes was established and the effect of the acid and alkali treatments on the degree of polymerisation of the resultant cellulose determined. Surface and bulk analyses and solubility tests suggested that alkali alone could not remove the DMDHEU from the crease-resist-treated cotton fabric. However, a sequential acid/alkali treatment effectively removed the easy-care finish from the cotton fabric and produced a commercially viable yield of cellulose.

The main goal of this work is to study the effect of different concentration level of alkaline solution for oil palm empty fruit bunch (OPEFB) fibre structure. As to achieve this objective, the OPEFB fibres were treated with 2 hours of soaking time with 3%, 5%, 7%, and 10% of sodium hydroxide (NaOH) concentration portion. The single test for treated and untreated fibers was then carried out according to the ASTM D3822-07 standard. Next, the surfaces of the fibres prior and after the treatment were observed with a scanning electron microscope (SEM) TM3000. The result shows that the 3% of the NaOH concentration exhibits better tensile strength compared to the other concentrations and untreated fiber.

The key objective of this work was to study the effect of multiple surface treatments on the oil palm empty fruit bunch (OPEFB) fibres. To achieve this purpose, the OPEFB fibres were treated with the sodium hydroxide (NaOH) (3%), silane (2%), a combination of NaOH (3%) and silane (2%) (NaOH+silane), and NaOH (3%) prior silane (2%) (NaOH-silane). The soaking time was standardized for 7 hours. The multiple treated and untreated fibres were subjected to single fibre test and scanning electron microscopy (SEM). The single fibre tests were performed according to ASTM D3822-07 standard using INSTRON Micro tester while microscopy was observed by using Scanning Electron Microscope (SEM) TM3000. The result shows that the treated fibres with 3% concentration of NaOH have achieved the maximum ultimate tensile stress of 82.04 MPa compared with other treatment and untreated fibre.