scholarly journals Moisture resistant and biofriendly CD-MOF nanoparticles obtained via cholesterol shielding

2017 ◽  
Vol 53 (66) ◽  
pp. 9246-9249 ◽  
Author(s):  
Vikramjeet Singh ◽  
Tao Guo ◽  
Haitong Xu ◽  
Li Wu ◽  
Jingkai Gu ◽  
...  

A facile and one step-method was developed to enhance the water stability of CD-MOF nanoparticles through surface modification with cholesterol.

2021 ◽  
Vol 8 (8) ◽  
pp. 210582
Author(s):  
Manjit Singh Grewal ◽  
Hiroya Abe ◽  
Yasutaka Matsuo ◽  
Hiroshi Yabu

We propose a surface modification of poorly dispersive polytetrafluoroethylene (PTFE) particles via bioinspired polydopamine–polyethyleneimine (PDA–PEI) which conferred PTFE particles a uniform dispersion in aqueous medium. With increasing dopamine concentration in the reaction solution, dispersity of PTFE particles improved and the surface charges of particles changed from negative to positive due to an increase of surface coverage of PDA–PEI layers. Simplicity of the method here outlines an attractive route for surface modification of inert surfaces useful for large-scale applications.


2006 ◽  
Vol 11-12 ◽  
pp. 437-440 ◽  
Author(s):  
Wei Ning ◽  
Jian Ping Deng ◽  
Wan Tai Yang

Surface modification of low-density polyethylene (LDPE) films was carried out via a novel photografting polymerization technique with acrylamide (AAm) as the monomer. The photografting polymerization can be achieved via one-step method and two-step method. The photografting polymerization reactivity of AAm was examined with benzophenone (BP) as the photoinitiator and low-density polyethylene (LDPE) film as the substrate with “sandwich” assembly. Moreover, the occurrence and evolution of grafting polymerization of AAm on the substrate was demonstrated XPS analysis and SEM pictures.


2020 ◽  
Vol 27 (10) ◽  
pp. 1616-1633 ◽  
Author(s):  
Oana Cristina Duta ◽  
Aurel Mihail Ţîţu ◽  
Alexandru Marin ◽  
Anton Ficai ◽  
Denisa Ficai ◽  
...  

Polymeric materials, due to their excellent physicochemical properties and versatility found applicability in multiples areas, including biomaterials used in tissue regeneration, prosthetics (hip, artificial valves), medical devices, controlled drug delivery systems, etc. Medical devices and their applications are very important in modern medicine and the need to develop new materials with improved properties or to improve the existent materials is increasing every day. Numerous reasearches are activated in this domain in order to obtain materials/surfaces that does not have drawbacks such as structural failure, calcifications, infections or thrombosis. One of the most used material is poly(vinylchloride) (PVC) due to its unique properties, availability and low cost. The most common method used for obtaining tubular devices that meet the requirements of medical use is the surface modification of polymers without changing their physical and mechanical properties, in bulk. PVC is a hydrophobic polymer and therefore many research studies were conducted in order to increase the hydrophilicity of the surface by chemical modification in order to improve biocompatibility, to enhance wettability, reduce friction or to make lubricious or antimicrobial coatings. Surface modification of PVC can be achieved by several strategies, in only one step or, in some cases, in two or more steps by applying several techniques consecutively to obtain the desired modification / performances. The most common processes used for modifying the surface of PVC devices are: plasma treatment, corona discharge, chemical grafting, electric discharge, vapour deposition of metals, flame treatment, direct chemical modification (oxidation, hydrolysis, etc.) or even some physical modification of the roughness of the surface.


1993 ◽  
Vol 58 (11) ◽  
pp. 2642-2650 ◽  
Author(s):  
Zdeněk Kruliš ◽  
Ivan Fortelný ◽  
Josef Kovář

The effect of dynamic curing of PP/EPDM blends with sulfur and thiuram disulfide systems on their mechanical properties was studied. The results were interpreted using the knowledge of the formation of phase structure in the blends during their melt mixing. It was shown, that a sufficiently slow curing reaction is necessary if a high impact strength is to be obtained. Only in such case, a fine and homogeneous dispersion of elastomer can be formed, which is the necessary condition for high impact strength of the blend. Using an inhibitor of curing in the system and a one-step method of dynamic curing leads to an increase in impact strength of blends. From the comparison of shear modulus and impact strength values, it follows that, at the stiffness, the dynamically cured blends have higher impact strength than the uncured ones.


2019 ◽  
Vol 375 ◽  
pp. 122000 ◽  
Author(s):  
Yang Xuan ◽  
Xian-Lin Song ◽  
Xiao-Quan Yang ◽  
Ruo-Yun Zhang ◽  
Zi-Yu Song ◽  
...  

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3138
Author(s):  
Kamila Gosz ◽  
Agnieszka Tercjak ◽  
Adam Olszewski ◽  
Józef Haponiuk ◽  
Łukasz Piszczyk

The utilization of forestry waste resources in the production of polyurethane resins is a promising green alternative to the use of unsustainable resources. Liquefaction of wood-based biomass gives polyols with properties depending on the reagents used. In this article, the liquefaction of forestry wastes, including sawdust, in solvents such as glycerol and polyethylene glycol was investigated. The liquefaction process was carried out at temperatures of 120, 150, and 170 °C. The resulting bio-polyols were analyzed for process efficiency, hydroxyl number, water content, viscosity, and structural features using the Fourier transform infrared spectroscopy (FTIR). The optimum liquefaction temperature was 150 °C and the time of 6 h. Comprehensive analysis of polyol properties shows high biomass conversion and hydroxyl number in the range of 238–815 mg KOH/g. This may indicate that bio-polyols may be used as a potential substitute for petrochemical polyols. During polyurethane synthesis, materials with more than 80 wt% of bio-polyol were obtained. The materials were obtained by a one-step method by hot-pressing for 15 min at 100 °C and a pressure of 5 MPa with an NCO:OH ratio of 1:1 and 1.2:1. Dynamical-mechanical analysis (DMA) showed a high modulus of elasticity in the range of 62–839 MPa which depends on the reaction conditions.


2013 ◽  
Vol 321-324 ◽  
pp. 209-212
Author(s):  
Chun Yan Xia

nfluences on properties of the concrete highway pavement were analyzed in this paper, and the optimal formulation materials were gotten to use in the repair of used-broken cement blocks in the experiment. Polyurethane concrete material was prepared, combing the ordinary concrete technology with one-step method of the synthesis of polyurethane hard bubble, and then its mechanical properties of the relevant parameters were measured to determine the optimal preparation program. The results show that the polyurethane concrete also has sufficiently good mechanical properties while it has the characteristic of fast patching.


2002 ◽  
Vol 43 (21) ◽  
pp. 3887-3890 ◽  
Author(s):  
Michael R. Wood ◽  
June Y. Kim ◽  
Kathy M. Books

Nanoscale ◽  
2021 ◽  
Author(s):  
Wipakorn Jevasuwan ◽  
Naoki Fukata

Vertical Al-catalyzed SiNW arrays with shaped surfaces were synthesized by a one-step process and NW-based solar cells were demonstrated with optimized NW surface defects through surface modification and length reduction.


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