Comparative Investigation of Coprecipitation and In-Situ Synthesis of Nanohydroxyapatite/Collagen Composite

2005 ◽  
Vol 284-286 ◽  
pp. 839-842 ◽  
Author(s):  
Xiao Yan Lin ◽  
Xu Dong Li ◽  
Hong Song Fan ◽  
Yu Mei Xiao ◽  
Jian Lu ◽  
...  

Hydroxyapatite/collagen (HA/COL) composites were prepared using coprecipitation and in-situ synthesis methods. All these processes yielded nanosize poorly crystallized hydroxyapatite/collagen composites. The low temperature in situ formed composites showed some features of natural bone in phase composition, crystal size and crystallinity. Compare with the composite prepared by coprecipitation synthesis, the composite resulted from a low temperature in situ synthesis method showed better homogeneity and mechanical properties. It is confirmed that the low temperature in situ synthesis method was an effective way to obtain biomimetic nanoHA/COL composites with good homogeneity and mechanical properties.

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4472
Author(s):  
Anja Verbič ◽  
Martin Šala ◽  
Ivan Jerman ◽  
Marija Gorjanc

This work presents the novel and entirely green in situ synthesis of zinc oxide nanoparticles (ZnO-NP) on cotton fabric. Pomegranate peel extract was used as a reducing agent and wood ash extract was used as an alkali source for the formation of ZnO-NP from zinc acetate. Four different synthesis methods, which varied in drying between immersion of fabric in the active solutions for synthesis and the use of padding and ultrasonication, were investigated to evaluate the most suitable one to achieve excellent ultraviolet (UV) protective properties of the functionalized textile. For comparison, the cotton fabrics were also functionalized with each active solution separately or in a combination of two (i.e., Zn-acetate and plant extract). Scanning electron microscopy (SEM), inductively coupled plasma mass spectroscopy (ICP-MS), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometry (XRD) analysis, and atomic force microscopy (AFM) confirm the successful formation of ZnO-NP on cotton. Among the synthesis methods, the method that included continuous drying of the samples between immersion in the active solutions for synthesis (Method 4) was found to be the most suitable to deliver uniformly impregnated cotton fibers with numerous small ZnO wurtzite structured crystals and excellent UV protection, with a UV protection factor of 154.0. This research presents an example of a green circular economy where a bio-waste material can be used to produce ZnO-NP directly on cotton at low temperatures and short treatment times without the addition of chemicals and enables the production of cellulosic fabrics with excellent UV protection.


2021 ◽  
Author(s):  
Jiahong Tian ◽  
Runhua Fan ◽  
Zongxiang Wang ◽  
Jiahao Xin ◽  
Zhongyang Wang

Abstract Silver/polyaniline (Ag/PANI) composites were prepared by an in-situ synthesis method. Interestingly, the permittivity changed from positive to negative along with the formation of percolation network. The plasma oscillations of free electrons from the network made a dominant effect on the negative permittivity behavior. Further investigation based on equivalent circuit analysis revealed that the composites with negative permittivity presented inductive character. The epsilon-negative composites can be applied to electromagnetic shielding, absorbing and attenuation.


Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1121 ◽  
Author(s):  
Li ◽  
Liang ◽  
Tian ◽  
Yang ◽  
Xie ◽  
...  

Titanium composite strengthened by Ti3Al precipitations is considered to be one of the excellent materials that is widely used in engineering. In this work, we prepared a kind of Ti-Ti3Al metallic composite by in-situ synthesis technology during the SLM (selective laser melting) process, and analyzed its microstructure, wear resistance, microhardness, and compression properties. The results showed that the Ti-Ti3Al composite, prepared by in-situ synthesis technology based on SLM, had more homogeneous Ti3Al-enhanced phase dispersion strengthening structure. The grain size of the workpiece was about 1 μm, and that of the Ti3Al particle was about 200 nm. Granular Ti3Al was precipitated after the aluminum-containing workpiece formed, with a relatively uniform distribution. Regarding the mechanical properties, the hardness (539 HV) and the wear resistance were significantly improved when compared with the Cp-Ti workpiece. The compressive strength of the workpiece increased from 886.32 MPa to 1568 MPa, and the tensile strength of the workpiece increased from 531 MPa to 567 MPa after adding aluminum. In the future, the combination of in-situ synthesis technology and SLM technology can be used to flexibly adjust the properties of Ti-based materials.


2015 ◽  
Vol 3 (15) ◽  
pp. 8205-8214 ◽  
Author(s):  
Jia Wei ◽  
Shuo Zhang ◽  
Xiaoyun Liu ◽  
Jun Qian ◽  
Jiasong Hua ◽  
...  

BaTiO3/MWNT/PBO ternary composites with excellent microwave absorption properties, mechanical properties and thermostabilities.


2007 ◽  
Vol 330-332 ◽  
pp. 349-352
Author(s):  
Xiao Yan Lin ◽  
Xu Dong Li ◽  
Xing Dong Zhang

Hydroxyapatite/collagen composites were prepared in-situ synthesis. The composites were finally achieved by dehydration including air-drying and freeze-drying methods. FTIR, XPS and DSC were employed to investigate the composites dehydrated by two methods. The air-dried composites had better mechanical properties than those of the composites dried by freeze drying. Air-drying of the composite induced more bond formation and crosslink between collagen fibers and HA crystals compared with freeze-drying of the composite, as indicated by the shifting of amide A and I bands to the lower wavenumber and by the changes in the binding energy of O1s, Ca2p, and P2p, leading to the increase of the peak temperature of the composites. Collagen crosslink and bond formation in the air-dried composites were key factors to increase the bending strength of the composites. The results of this study confirm that in situ synthesis and air-dry method are effective ways to obtain nanoHA/COL composites with high mechanical properties.


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