scholarly journals Synthesis of Silica-Based Solid-Acid Catalyst Material as a Potential Osteochondral Repair Model In Vitro

Author(s):  
Rui-Min Long ◽  
Yan Jiang ◽  
Jia-Qi Guo ◽  
Gang Ren ◽  
Xian-Xin Guo ◽  
...  

For osteochondral damage, the pH value change of the damaged site will influence the repair efficacy of the patient. For better understanding the mechanism of the acid-base effect, the construction of in vitro model is undoubtedly a simple and interesting work to evaluate the influence. Here, a novel porous silica-based solid-acid catalyst material was prepared by additive manufacturing technology, exhibiting improved eliminating effects of the residue. SEM, FTIR, and TGA were used to characterize the morphology, structure, and thermal stability of the synthesized 3D material. The reaction between 4-methoxybenzyl alcohol and 3, 4-dihydro-2H-pyran was used as a template reaction to evaluate the eliminating performance of the 3D porous material. Solvents were optimized, and three reaction groups in the presence of 3D SiO2, 3D SiO2-SO3H, and 3D SiO2-NH-SO3H, as well as one without catalyst, were compared. In addition, in consideration of the complicated situation of the physiological environment in vivo, universality of the synthesized 3D SiO2-NH-SO3H catalyst material was studied with different alcohols. The results showed that the sulfonic acid-grafted 3D material had excellent catalytic performance, achieving a yield over 95% in only 20 min. Besides, the catalyst material can be recycled at least 10 times, with yields still higher than 90%. Such a solid catalyst material is expected to have great potential in additive manufacturing because the catalyst material is easy-recyclable, renewable and biocompatible. The 3D material with connective channels may also be utilized as an in vitro model for environment evaluation of osteochondral repair in the future.

ACS Omega ◽  
2021 ◽  
Vol 6 (5) ◽  
pp. 3875-3883
Author(s):  
Yixuan Huang ◽  
Guangcai Zhang ◽  
Qinhui Zhang

2018 ◽  
Vol 2 (2) ◽  
Author(s):  
Seyed Yousef Mosavian

Zirconia was synthesized in nanosize by sol-gel method and perchlorated zirconia (HClO4/ZrO2) with various calcination temperatures were prepared and characterized by XRD, FTIR and SEM techniques. The catalyst acidity characters, including the acidicstrength and the total number of acid sites were determined by potentiometric titration. The catalytic performance experiments show that the HClO4/ZrO2 with calcination temperature of 300 °C has the best catalytic activity. 2,3-Dihydroquinazolin-4(1H)-ones wereprepared in good to excellent yields via condensation reaction of oaminobenzamide and various types of aldehydes and ketones in the presence of HClO4/ZrO2 nanoparticles as an efficient solid acid catalyst. The catalyst is reusable with moderate loss in activity.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
W. N. R. W. Isahak ◽  
M. Ismail ◽  
N. M. Nordin ◽  
J. M. Jahim ◽  
M. A. Yarmo

The purpose of this work is to study the synthesis, characterization, and catalytic performance of two types of solid heteropoly acid catalysts, namely, silicotungstic acid bulk (STAB) and STA-silica sol-gel (STA-SG) compared with sulfuric acid. From the XPS analyses, there was a significant formation of W-O-Si, W-O-W, and Si-O-Si bonding in STA-SG compared to that in STAB. The main spectra of O1s (90.74%, 531.5 eV) followed by other O1s peak (9.26%, 532.8 eV) were due to the presence of W-O-W and W-O-Si bonds, respectively. The STA-SG catalyst was found to be the more environmentally benign solid acid catalyst for the esterification reaction between oleic acid and glycerol due to its lower toxicity supported by silica via sol-gel technique. In addition, the ease of separation for STA-SG catalyst was attributed to its insoluble state in the product phase. The esterification products were then analysed by FTIR and HPLC. Both the H2SO4and the STAB gave high conversion of 100% and 98% but at a lower selectivity of GME with 81.6% and 89.9%, respectively. On the contrary, the STA-SG enabled a conversion of 94% but with a significantly higher GME selectivity of 95%, rendering it the more efficient solid acid catalyst.


2016 ◽  
Vol 81 (2) ◽  
Author(s):  
Sri WAHYUNI ◽  
Heru SETYAWA

AbstractThe use of a catalyst in the manufacture of lubricantscome through many developments, from a homogeneousbase catalysts, homogeneous acid catalyst to hetero-geneous solid catalyst system (heterogenous catalyst). Oneexample of heterogeneous catalyst base material is silica.The purpose of this research was to study the graftingmethod of sulfonic group on silica from waterglass withPEG (polyethylene glycol) template as solid acid catalystand to analyze the effect of PEG concentration on ioniccapacity. Silica sol was produced by addition of PEG andHCl into waterglass. The PEG template was separated bytwo different methods; solvothermal extraction andcalcinations process. The following step was graftingprocess of the sulfonate into the silica powder, and dryingthe silica sulfonate in certain temperature. The driedsulfonated silica particles were characterized for theirpore size by BET method, the functional group by FTIR(Fourier Transform Infra Red) test, and the ionic capacityby titrimetry analysis. The result showed that the separatedPEG template process with calcinations method gave abetter result than the solvothermal extraction methodbased on the amount of PEG that disappear. While fromBET result showed that the calcinations process producedsmaller surface area pore than the extraction solvothermalprocess. The effect of the concentration of PEG template,showed that the surface area mostly decreased with theaddition of the PEG template concentration and increasedagain at 0.0178 g/mL. The biggest ionic capacity at 12,603mmol eq/g silica was obtained from solvothermal method.AbstrakPenggunaan katalis dalam pembuatan pelumas me-ngalami banyak perkembangan, dari katalis homogenbasa, katalis homogen asam hingga dikembangkanpenggunaan katalis padat sistem heterogen (heterogenouscatalyst). Salah satu contoh bahan dasar dari katalisheterogen ini adalah silika. Penelitian ini bertujuan untukmempelajari teknik pencangkokan gugus sulfonat pada silika dari waterglass dengan templat PEG (polyethyleneglycol) sebagai katalis asam padat dan menganalisapengaruh konsentrasi templat terhadap kapasitas ion. Solsilika dibuat dengan menambahkan PEG dan HCl kedalam waterglass. Templat PEG dihilangkan dengan duacara yang berbeda yaitu ekstraksi solvothermal dankalsinasi. Proses selanjutnya adalah pencangkokansulfonat pada serbuk silica dan silika tersulfonasi padasuhu tertentu. Partikel silika tersulfonasi yang telah keringdikarakterisasi ukuran porinya dengan metode BET,gugus fungsi dengan uji FTIR (Fourier Transform InfraRed), dan kapasitas ionik dengan analisis titrimetri. Hasilpenelitian menunjukkan bahwa metode kalsinasi ternyatadapat menghilangkan senyawa PEG lebih baik di-bandingkan dengan metode ekstraksi solvothermal, tetapiberdasarkan hasil BET, penghilangan templat melaluiproses kalsinasi menghasilkan luas permukaan yang lebihkecil jika dibandingkan dengan kondisi sebelum templatdihilangkan, sedangkan ekstraksi solvothermal meng-hasilkan luas permukaan silika yang lebih besar. Untukpengaruh konsentrasi templat PEG, didapatkan hasilbahwa luas permukaan partikel silika cenderung turundengan penambahan templat dan naik kembali padakonsentrasi 0,0178 g/mL. Kapasitas ionik terbesar di-dapat pada silika dengan metode solvothermal yaitusebesar 12,603 mmol/g silika.


Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 710 ◽  
Author(s):  
Xiaochuan Zou ◽  
Xuyuan Nie ◽  
Zhiwen Tan ◽  
Kaiyun Shi ◽  
Cun Wang ◽  
...  

In this paper, a solid acid catalyst (ZPS–PVPA–SO3H) was prepared by anchoring thiol group on zirconium poly(styrene-phenylvinyl-phosphonate)-phosphate (ZPS–PVPA), followed by oxidation of thiol groups to obtain sulfonic acid groups. The solid acid catalyst was characterized by XPS, X-ray, EDS, SEM, and TG-DSC. The successful preparation of sulfonic acid-functionalized ZPS–PVPA was confirmed. Subsequently, the catalytic performance of ZPS–PVPA–SO3H was investigated in the epoxidation of soybean oil. The results demonstrated that ZPS–PVPA–SO3H can effectively catalyze epoxidation of soybean oil with TBHP as an oxidant. Moreover, there was no significant decrease in catalytic activity after 5 repeated uses of the ZPS–PVPA–SO3H. Interestingly, the ZPS–PVPA–SO3H was kept in 2 mol/L of HCl overnight after the end of the seventh reaction, and the catalytic activity was gradually restored during the eighth to tenth cycles.


2010 ◽  
Vol 173 ◽  
pp. 140-145 ◽  
Author(s):  
Nor Asikin Mohamad Nordin ◽  
Nadia Farhana Adnan ◽  
Aznira Alias ◽  
Wan Nor Roslam Wan Isahak ◽  
Jumat Salimon ◽  
...  

The syntheses of estolides via condensation reaction of oleic acid were investigated using heterogenous catalysts. In this study HClO4 is supported onto suitable support to make it environmentally friendly. A series of solid acid catalyst containing 5-45 % of perchloric acid supported onto silica was synthesized and characterized using XRD, BET surface area measurement, TEM and XPS surface analysis. Silica modified with perchloric acid was found to be efficient and environmentally benign solid acid catalyst for estolide synthesis. The reaction was performed at 70 oC for 10 hours to give oleic-oleic monoestolide acid (m/z 563.51 as M-H)-. Based on the experimental findings above, optimum catalytic performance was with 15 % HClO4 loading onto SiO2 to give 98.98 % conversion of the oleic acid with 63.98 % oleic-oleic monoestolide acid selectivity.


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