MOF is a new class of material with lots of opportunity for future work. It is a coordination compound. Obviously MOF is a attractive subject for a group of researcher.
Synthesis and Characterization of MOF based Composites for Energy storage app...Danyal Hakeem Jokhio
Despite extensive efforts and research put in the field, conventional energy storage devices (ESDs) such as various supercapacitors and batteries are near their performance limit in terms of power densities, energy densities, capacitance, charge retention, and cyclic stability. This is primarily due to limiting intrinsic properties of the electrode materials such as average surface area and poor porosity, combined with sluggish redox kinetics due to lack of electrode functionality. So, the need of the hour is to explore new materials for efficient storage of the energy. Among these new materials, metal-organic frameworks (MOFs) can serve as potential candidates because they have high specific surface area, high porosity with tuneable morphology and hence tuneable pore size, functionality linking to active metal sites and ligands. However, there remains a gap in fully utilising MOFs in energy storage applications commercially. Due to the highly porous nature of MOFs, their structural stability is compromised especially in aqueous electrolytes. To utilize the maximum potential of MOFs as electrode materials, it is of utmost importance to address poor structural integrity and low intrinsic conductivity of MOFs.
In this work, it has been tried to overcome the above-mentioned drawbacks of MOFs by using additives of conductive nature such as graphene nanoplatelets (GNP). Hydrothermal approach was used to synthesize hybrid MOF by controlling molar ratio of Nickel and Cobalt in combination with different organic ligands. As a battery-type supercapacitor electrode material, the 2:1 Ni/Co hybrid MOF with 40mg GNP, using terephthalic acid as ligand, delivered a high specific capacity of 658.8 C·g−1 at the current density of 1 A·g−1. Similarly, the 1:2 Ni/Co hybrid MOF, using 2-MethylImidazole as ligand, delivered a high specific capacity of 642.4 C·g−1 at the current density of 1 A·g−1. Moreover, breakthrough results were obtained by optimizing synthesis with in-situ deposition on nickel foam of 2:1 Ni/Co (with 40mg GNP) hybrid MOF, which produced an impressive specific capacity of 1264 C·g−1 at 1 A/g, surpassing, to the best of our knowledge, most of the previously reported MOF based electrode materials.
This work not only develops a high-performance electrode material of supercapacitor, but being the first of its kind in Pakistan, also provides the foundation of systematic research for the electrochemical properties of multi-metal MOFs.
MOFs are ideal candidates as gas-sensing materials and have been widely used to detect oxygen, water vapor, toxic and hazardous gases, special air pollutants, and VOCs.
MOF is a new class of material with lots of opportunity for future work. It is a coordination compound. Obviously MOF is a attractive subject for a group of researcher.
Synthesis and Characterization of MOF based Composites for Energy storage app...Danyal Hakeem Jokhio
Despite extensive efforts and research put in the field, conventional energy storage devices (ESDs) such as various supercapacitors and batteries are near their performance limit in terms of power densities, energy densities, capacitance, charge retention, and cyclic stability. This is primarily due to limiting intrinsic properties of the electrode materials such as average surface area and poor porosity, combined with sluggish redox kinetics due to lack of electrode functionality. So, the need of the hour is to explore new materials for efficient storage of the energy. Among these new materials, metal-organic frameworks (MOFs) can serve as potential candidates because they have high specific surface area, high porosity with tuneable morphology and hence tuneable pore size, functionality linking to active metal sites and ligands. However, there remains a gap in fully utilising MOFs in energy storage applications commercially. Due to the highly porous nature of MOFs, their structural stability is compromised especially in aqueous electrolytes. To utilize the maximum potential of MOFs as electrode materials, it is of utmost importance to address poor structural integrity and low intrinsic conductivity of MOFs.
In this work, it has been tried to overcome the above-mentioned drawbacks of MOFs by using additives of conductive nature such as graphene nanoplatelets (GNP). Hydrothermal approach was used to synthesize hybrid MOF by controlling molar ratio of Nickel and Cobalt in combination with different organic ligands. As a battery-type supercapacitor electrode material, the 2:1 Ni/Co hybrid MOF with 40mg GNP, using terephthalic acid as ligand, delivered a high specific capacity of 658.8 C·g−1 at the current density of 1 A·g−1. Similarly, the 1:2 Ni/Co hybrid MOF, using 2-MethylImidazole as ligand, delivered a high specific capacity of 642.4 C·g−1 at the current density of 1 A·g−1. Moreover, breakthrough results were obtained by optimizing synthesis with in-situ deposition on nickel foam of 2:1 Ni/Co (with 40mg GNP) hybrid MOF, which produced an impressive specific capacity of 1264 C·g−1 at 1 A/g, surpassing, to the best of our knowledge, most of the previously reported MOF based electrode materials.
This work not only develops a high-performance electrode material of supercapacitor, but being the first of its kind in Pakistan, also provides the foundation of systematic research for the electrochemical properties of multi-metal MOFs.
MOFs are ideal candidates as gas-sensing materials and have been widely used to detect oxygen, water vapor, toxic and hazardous gases, special air pollutants, and VOCs.
metal organic framework-carbon capture and sequestrationVasiUddin Siddiqui
MOF is a porous crystal like a spunge having an enormous surface area and provide much more rooms for storage the gases preferentially hydrogen and carbon dioxide and work as storage for next generation fuel.
Gas storage in metal organic frameworks(MOFs)Nitish Kumar
Gas storage in metal organic frameworks.
1. Metal organic frameworks has surface area more than 40 tennis courts per gram. So, it has high adsorption capacity.
2. Gas storage in a cylinder filled with MOFs can store much more gas than empty cylinder.
3. Apart from storage ,MOFs can also be used for Gas Separation.
Nanoparticle synthesis using electrochemical method. Detailed process of electrochemical cell and synthesis. nanoparticle synthesis method.electrochemistry
An overview of the use of the Marcus Theory to calculate the energies of transition states.
Contributed by: Elizabeth Greenhalgh, Amanda Bischoff, and Matthew Sigman, University of Utah, 2015
It's simple to understand the synthesis. Hydrothermal method is a chemical reaction in water in a sealed pressure vessel, which is in fact a type of reaction at both high temperature and pressure.
This presentation describes about the preparation, properties, bonding modes, classification and applications of metal Dioxygen Complexes. Also explains the MO diagram of molecular oxygen.
Novel effects can occur in materials when structures are formed with sizes comparable to any one of many possible length scales, such as the de Broglie wavelength of electrons, or the optical wavelengths of high energy photons. In these cases quantum mechanical effects can dominate material properties. One example is quantum confinement where the electronic properties of solids are altered with great reductions in particle size. The optical properties of nanoparticles, e.g. fluorescence, also become a function of the particle diameter. This effect does not come into play by going from macrosocopic to micrometer dimensions, but becomes pronounced when the nanometer scale is reached.
degradation of pollution and photocatalysisPraveen Vaidya
The presentation deals with the use of conduction of photocatalytic reaction using the transition metal doped transparent semiconducting thinfilms. The precursor to film is prepared by the SILAR method, which is a chemical method.
metal organic framework-carbon capture and sequestrationVasiUddin Siddiqui
MOF is a porous crystal like a spunge having an enormous surface area and provide much more rooms for storage the gases preferentially hydrogen and carbon dioxide and work as storage for next generation fuel.
Gas storage in metal organic frameworks(MOFs)Nitish Kumar
Gas storage in metal organic frameworks.
1. Metal organic frameworks has surface area more than 40 tennis courts per gram. So, it has high adsorption capacity.
2. Gas storage in a cylinder filled with MOFs can store much more gas than empty cylinder.
3. Apart from storage ,MOFs can also be used for Gas Separation.
Nanoparticle synthesis using electrochemical method. Detailed process of electrochemical cell and synthesis. nanoparticle synthesis method.electrochemistry
An overview of the use of the Marcus Theory to calculate the energies of transition states.
Contributed by: Elizabeth Greenhalgh, Amanda Bischoff, and Matthew Sigman, University of Utah, 2015
It's simple to understand the synthesis. Hydrothermal method is a chemical reaction in water in a sealed pressure vessel, which is in fact a type of reaction at both high temperature and pressure.
This presentation describes about the preparation, properties, bonding modes, classification and applications of metal Dioxygen Complexes. Also explains the MO diagram of molecular oxygen.
Novel effects can occur in materials when structures are formed with sizes comparable to any one of many possible length scales, such as the de Broglie wavelength of electrons, or the optical wavelengths of high energy photons. In these cases quantum mechanical effects can dominate material properties. One example is quantum confinement where the electronic properties of solids are altered with great reductions in particle size. The optical properties of nanoparticles, e.g. fluorescence, also become a function of the particle diameter. This effect does not come into play by going from macrosocopic to micrometer dimensions, but becomes pronounced when the nanometer scale is reached.
degradation of pollution and photocatalysisPraveen Vaidya
The presentation deals with the use of conduction of photocatalytic reaction using the transition metal doped transparent semiconducting thinfilms. The precursor to film is prepared by the SILAR method, which is a chemical method.
2017 - Cr(VI) Reduction and Immobilization by Core-Double-Shell Structured Ma...DrChimie
la courbe d'étalonnage peut être configurée en mesurant ou en entrant jusqu'à 10 étalons ou en entrant K et B facteurs
la courbe d'étalonnage peut être configurée en mesurant ou en entrant jusqu'à 10 étalons ou en entrant K et B facteurs
Green synthesis of iron-organic framework Fe-BTC using direct ultrasound to r...IJAEMSJORNAL
Metal-organic framework materials (MOFs) comprise organic bridges and metal centers (as connection points). MOFs have unique properties such as crystal structure, large specific surface area, flexible structural framework, and can change the size and shape of pores and diverse chemical functional groups inside the pores. In this study, metal-organic framework materials based on iron (Fe) and the organic ligand H3BTC were successfully synthesized by ultrasonic method and evaluated for their ability to remove MB dye through Investigate the effects of MB concentration, pH, isotherm model, and adsorption kinetics. With a size of about 100 - 200 nm and an excitation wavelength in the ultraviolet region, the synthesized material shows potential in environmental treatment when the adsorption efficiency reaches over 60% after just 10 minutes and over 80% both processes under sunlight conditions. In addition, the synthesized material is also evaluated to have selective adsorption with Methylene Blue dye.
Metal-organic molybdenum complexes were synthesized by the hydrothermal method using ammonium heptamolybdate as the metallic source, and as the organic ligand terephthalic acid (BDC) or bis(2-hydroxyethyl) terephthalate (BHET), obtained via glycolysis of poly(ethylene)terephthalate (PET). The BDC-Mo and BHET-Mo complexes were characterized by XRD, N2 physisorption, TGA, ATR-FTIR, SEM, XPS and their in vitro biocompatibility was tested by porcine fibroblasts viability. The results show that molybdates (MoO4-2) are coordinated to the carbonyl functional groups of BDC and BHET by urea bonding (-NH-CO-NH-) which is related to their high biocompatibility and high thermal stability. These organic molybdate complexes possess rectangular prism particles made up of rods arrays characteristics of molybdenum oxides (MoO3). The organic complexes BDC-Mo and BHET-Mo do not show to be cytotoxic for porcine dermal fibroblasts growing on their surface for up to 48 h of culture.
Synthesis and Characterization of High Quality Mesoporous Material SBA-16 wit...iosrjce
IOSR Journal of Applied Physics (IOSR-JAP) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of physics and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in applied physics. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
Effect of the pillar ligand on preventing agglomeration of ZnO nanoparticles ...Iranian Chemical Society
Metal-Organic Frameworks (MOFs) represent a new class of highly porous materials. On this regard, two nano porous metal-organic frameworks of [Zn2(1,4-bdc)2(H2O)2∙(DMF)2]n (1) and [Zn2(1,4-bdc)2(dabco)]·4DMF·1⁄2H2O (2), (1,4-bdc = benzene-1,4-dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]octane and DMF = N,N-dimethylformamide) were synthesized and characterized. They were used for preparation of ZnO nanomaterials. With calcination of 1, agglomerated ZnO nanoparticles could be fabricated, but by the same process on 2, the tendency of ZnO nanoparticles to agglomeration was decreased. In addition, the ZnO nanoparticles prepared from compound 2 had smaller diameter than those obtained from compound 1. In fact, the role of organic dabco ligands in 2 is similar to the role of polymeric stabilizers in formation of nanoparticles. Finally, considering the various applications of ZnO nanomaterials such as light-emitting diodes, photodetectors, photodiodes, gas sensors and dye-sensitized solar cells (DSSCs), it seems that preparation of ZnO nanomaterials from their MOFs could be one of the simple and effective methods which may be applied for preparation of them.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
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These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
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2. Preparation of Hollow MOF
1. Exterior-Template Method
Commonly consists of three processes:
1) synthesis of the template,
2) MOF shell cladding,
3) template removal.
the first exteriortemplate method to fabricate hollow-structured ZIF-8
(ZIF: zeolitic imidazolate framework) by using carboxylate-terminated polystyrene (PS) spheres
as the template.
2/19/2019 2HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
3. carboxylate-terminated PS spheres were synthesized with a uniform diameter. Subsequent addition of
the PS spheres into a mixture solution containing 2-methylimidazole and Zn(NO3)2 quickly resulted in
formation of ZIF-8 shells on the surfaces of the PS spheres. To further increase the shell thickness, the
second growth was conducted by using fresh ZIF-8 precursor solution. When the ZIF-8 shell was thick
enough, the synthesized PS@ZIF-8 core–shell microspheres were immersed in
N,N′-dimethylformamide (DMF) solution to remove the PS templates, and hollow-structured ZIF-8 was
prepared.
2/19/2019 3HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
4. The silica shells were first coated on the surface of Au NPs to form Au NP@silica
core–shell structures. Subsequent growth of ZIF-8 resulted in packaging multiple Au NP@silica
to generate “raisin bun”– like composites. After etching the silica, multicavity hollow
Au NPs@ZIF-8 nanostructures were acquired.
2/19/2019 4HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
5. 2) Self-Template Method
The self-template method is an advanced template technique, which avoids extra removal of the exterior
templates. Generally, the self-templates have two different types:
1) the intermediate products that spontaneously transform into hollow MOF structures
2) the reactants that act as sacrificial precursors for the formation of hollow MOFs via chemical reactions
Using the other one of the reactants as a template is introduced in the two-phase interface method section.
Similar to hollow metal oxide microspheres, hollow MOFs could be synthesized by self-template method. An easy
way to control the formation process of hollow MOF structures via the self-template method is surface protective
modification of the intermediate products before a subsequent transformation reaction. Use of
poly(vinylpyrrolidone) (PVP) has been reported as a surface protecting agent, followed by etching with HCl, to
prepare hollow Ga-soc-MOF structures.
2/19/2019 5HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
6. 3. Two-Phase Interface Method
Different from the exterior-template and self-template methods, the two-phase interface
method is more convenient and suitable for large-scale production. Generally, the synthesis of
hollow MOF structures by the two-phase interface method includes three types: gas–liquid,
liquid–liquid, and solid–liquid interface systems.
Among them, the gas–liquid interface system is widely applied, which involves two routes:
1)when the gas phase acts as the matrix, the liquid phase serves as the template (liquid in-gas)
2) when the liquid phase functions as the matrix, the gas phase serves as the template
(gas-in-liquid).
2/19/2019 6HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
7. Gas–liquid method via spray-drying synthesis
2/19/2019 7HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
8. In liquid–liquid interface synthesis, oil-in-water or water-in-oil emulsions are broadly adopted.
the metal salt in an aqueous phase and the organic ligand in an organic solvent were stored in
two separate syringe needles. Then, the aqueous droplets were added to the organic phase to
generate the interface of two incompatible solutions, where the MOF was grown and the hollow
HKUST-1 microstructures formed.
2/19/2019 8HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
9. solid–liquid-interface
MOP solid (UMOM-1) and 1,4-diazabicyclo[2.2.2]octane linker solution were mixed together. Since
the cores did not make contact with the solution, only the external surfaces reacted to form
MOP@MOF core–shell structures (I-a). By a subsequent etching process (I-b′), hollow MOFs of a
single shell were produced. In another method (I-b), epitaxial growth of an MOP precursor solution
on the above core–shell structures produced MOP@MOF@MOP structures. Repeating process I-a,
another MOF shell was formed. As a result, hollow MOFs with double shells were obtained after
etching.
2/19/2019 9HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
10. Hollow-MOF Derivatives
various physical and chemical methods have been utilized to prepare MOF derivatives, which are
assigned to two main catalogs:
1) the pyrolysis process and
2) solid–liquid reaction.
Especially, the pyrolysis process might be further classified into two subcatalogs based on different
gas atmosphere conditions:
1) self-pyrolysis in an inert atmosphere (N2, Ar, etc.),
2) solid–gas reaction in reactive gases/vapors (air, H2S, PH3, etc.).
On the other hand, the solid–liquid reaction upon MOFs with specific chemical reagents such as
acids, alkalis, and metal salts is a rapid chemical process, including chemical etching, ion exchange,
and so on.
2/19/2019 10HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
11. 1) Derived Hollow Metal Hydroxides: (Chemical reagents such as acids, bases, or metal salts have been used to
break the coordination bonds between the metal ions and organic ligands, inducing the transformation to metal
hydroxides.
2) Derived Hollow Metal Oxides: (Thanks to the abundant metal anodes (Fe, Co, Ni, Zn, Cu, Mg,Ti, Mn, and so
on) inside, MOFs are ideal candidates for constructing various hollow metal oxides. Pyrolysis of MOFs in air is an
easy and rapid way to produce hollow metal oxides. Hollow Fe2O3 was successfully derived from MIL-53(Fe) by
the pyrolysis method.
3) Derived Hollow Carbon Matrixes: (To fabricate a hollow carbon matrix, MOFs need to be subjected to self-
pyrolysis under an inert atmosphere (N2, Ar, etc.), which is different from the pyrolysis-involved synthesis of
hollow metal oxides in air.
4) Hollow Metal Phosphides, Metal Sulfides, and Metal Selenides: Other derivatives, such as hollow metal
phosphides, metal sulfides, and metal selenides, can be acquired with MOF templates through phosphorization,
sulfurization, and selenylation processes, respectively. Lou and co-workers used ZIF-67 nanocrystals as templates
and mixed them with Ni(NO3)2 solution, giving rise to the formation of hollow ZIF-67@Co-Ni LDHs core–shell
nanoboxes.
2/19/2019 11HOLLOW METAL–ORGANIC-FRAMEWORK MICRO/NANOSTRUCTURES
12. Porous metal–organic-framework nanoscale carriers as a
potential platform for drug delivery and imaging
2/19/2019 12
POROUS METAL–ORGANIC-FRAMEWORK NANOSCAL CARRIERS AS A POTENTIAL PLATFORM FOR
DRUGDELIVERY AND IMAGING
13. method
The syntheses of nanoscale porous iron(iii) carboxylates (labelled MIL-n) with different topologies and compositions (iron
trans,trans-muconate (MIL-89), fumarate (MIL-88A), tetramethylterephthalate (MIL-88Bt), terephthalate (MIL-53),
trimesate (MIL-100) and aminoterephthalate (MIL-101 _NH2) were optimized by an appropriate choice of the reaction
conditions (conventional solvothermal or microwave synthesis, solvent, additives, iron source, concentrations, energy,
temperature and time). These porous iron(iii) carboxylates are built up from the assembly of either oxo-centred trimers of
iron octahedra (MIL-88, MIL-89, MIL-100, MIL-101 _NH2) or chains of corner sharing octahedra (MIL-53) and di- or tri-
carboxylate linkers, leading either to microporous flexible solids (MIL-88, MIL-89, MIL-53) or mesoporous rigid
frameworks (MIL-100, MIL-101 _NH2). The structure and composition of the resulting nanoparticles were analysed using
X-ray powder diffraction, thermogravimetric analysis and infrared spectroscopy. In the case of MIL-53, MIL-88A, MIL-89,
MIL-100 and MIL-101_NH2, the synthesis could be carried out in water or ethanol.
2/19/2019 13
16. 1) Their in vitro degradation under physiological Conditions, in the case of MIL-88A (fumarate) and
MIL-100 (trimesate), a major degradation occurred after seven days of incubation at 37 C. The
nanoparticles lose their crystallinity and release large quantities of their ligands (72 and 58 wt% of
the fumaric and trimesic acids, respectively), indicating a reasonable in vitro degradability of the MOF
nanoparticles.
2) The nanoMOF cytotoxicity, studied in vitro (MTT assay) on mouse macrophages , was low
(57 ±11 µg ml¯ for MIL-88A) and comparable with that of the currently available nanoparticulate
systems.
3) Their comparison with control groups did not show significant differences between them, except a
slight increase in the spleen and liver weights, attributed to the fast sequestration by the
reticuloendothelial organs of the nanoMOFs not protected by a PEG (polyethylene glycol) coating. As
all the body organ weights were back to normality one to three months after injection.
2/19/2019 16
17. Metal–Organic Framework (MOF)-Based Drug/Cargo
Delivery and Cancer Therapy
2/19/2019
METAL–ORGANIC FRAMEWORK (MOF)-BASED DRUG/CARGO
DELIVERY AND CANCER THERAPY
MING-XUE WU AND YING-WEI YANG*
17
18. methods for drug-loading
Usually, there are two methods for drug-loading: one method
is a two-step encapsulation of drugs by immersing the prepared
MOFs nanocarriers into drug-containing solutions; the
other is a one-pot encapsulation of drugs.
2/19/2019 18
19. ZN base
Zn-based MOFs have also been reported as nanocarriers due to the low toxicity of zinc ion. For
example, reported a chiral Zn-based MOF constructed from 5,5′ 5′′-(1,3,5-triazine-2,4,6-triyl) tris
(azanediyl) triisophthalate (TATAT) and Zn2+ for the delivery of anticancer drug 5-fluorouracil (5-Fu).
Adsorption of 5-Fu was achieved by soaking the prepared MOF in 5-Fu containing methanol solutions,
and the hydrogen bonding interactions between 5-Fu and the MOF ensured a loading capacity
of 0.5 g −1.
Drug was released from the drug-loaded MOF by dialyzing the as prepared drug vehicle against
phosphate buffered saline (PBS) solution (pH 7.4) at room temperature, and the drug release process
lasted for a week.
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20. reported the first example of UiO MOFs for co-delivery of cisplatin and pooled siRNAs to enhance
their therapeutic efficacy by overcoming drug resistance in ovarian cancer cells. UiO MOF was
prepared with ZrCl4 and aminotriphenyldicarboxylic acid (amino- TPDC) bridging ligands, in which a
cisplatin prodrug and siRNA were sequentially loaded by encapsulating and coordinating to metal
sites on the MOF surfaces. Green fluorescence was clearly observed in cells incubated with
siRNA/UiO-cis, but not in those treated with siRNA/UiO or UiO-cis, indicating that the developed
siRNA/UiO-cis induce cell apoptosis (Figure 2b–d). All these results demonstrated that such a co-
delivery method would enhance the chemotherapeutic efficacy of cisplatin in vitro .
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21. Stimuli-Responsive MOFs for Drug Delivery
1) pH-Responsive MOFs: reported an Fe (bbi) MOF, constructed from 1,1′-(1,4-butanediyl) bis
(imidazole) (bbi) and ferrous ions by a deposition method. In situ encapsulation of DOX was
achieved by simply adding DOX into the bbi solution and, as expected, the loaded DOX could be
released upon lowering the pH, due to the sensitivity of the coordination bond to the acidic
environment . Thus, a layer of silica was coated on the surface of the MOF to prevent the rapid
decomposition of the hosting material for effective control over the release of DOX. More
importantly, folic acid was conjugated to the surface of the as-prepared nanocomposites for
targeted drug delivery.
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22. 1) Another pH-sensitive nanocarrier, poly(acrylic acid)@zeolitic imidazolate framework-8
(PAA@ZIF-8), was prepared by ionexchange between Zn2+ and poly(acrylic acid sodium salt)
(PAAS), followed by reacting with 2-methylimidazole (HMeIM) in methanol solution.
2) a pH-responsive ZIF-8 with uniform 70 nm NPs as a theranostic system.Negatively charged
small molecules such as fluorescein camptothecin (CPT) could be encapsulated into the ZIF-8
NPs by one-pot encapsulation. The performance of pH-responsive release was driven by the
dissociation of the ZIF-8 framework at the acidic designated target.
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23. Magnetically-Responsive MOFs
Candidate nanocarriers base on MOFs for such a delivery approach are usually core–shell
NPs, for example Fe3O4 was often used as a magnetic core with a MOF shell.
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24. Ion-Responsive MOFs
In such drug carriers, strong electrostatic interactions between the drugs and the frameworks
control the diffusion and release of drugs. Thus, the strong electrostatic interactions between
ionic drugs and ionic frameworks have attracted particular interest because the release of ionic
drugs is a chemical stimuli-responsive process taking place only through ion exchange.
Yang and co-workers developed a cationic drug carrier, MOF- 74-Fe(III), through the oxidation of
neutral MOF-74-Fe(II). The cationic MOF exhibited around 15.9 wt% of the loading capacity of
ibuprofen anions.
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25. Temperature-Responsive MOFs
Poly(N-isopropyl acrylamide) (PNIPAM) is a promising building block for thermosensitive drug
nanocarriers that possess a lower critical solution temperature.When the temperature is
lowered to below its cloud point (Tc, around 32 °C), PNIPAM exhibits hydrophilicity and tends to
dissolve in water; however, it also forms an aggregate. Accordingly, Sada et al. demonstrated a
switchable UiO-66- PNIPAM nanocarrier.
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26. Resorufin, caffeine, and procainamide were loaded in the nanocarrier by soaking the UiO-66-
PNIPAM in guest solutions, then the release behaviors were assessed at 25 °C or 40 °C . As
expected, the amount of released drug increased at 25 °C and almost halted at 40 °C , which
indicated that controlled release was driven by temperature variation.
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27. Pressure-Responsive MOFs
Recently, Qian and co-workers reported a Zr-based MOF builted from (2E,2E′)-3,3′-(2-fluoro-1,4-
phenylene) diacrylic acid (F-H2PDA) and zirconium cluster with high model drug diclofenac
sodium (DS) loading capacity of 58.80 wt% due to its enhanced polarity and extended organic
spacer. The Dsrelease kinetics of such drug-loaded MOF could be adjusted through varying
pressure, resulting in a prolonged release time between 2–8 days. Such formulation showed a
new method for responsive MOF-based drug delivery.
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29. dual stimuli-responsive
UMCM-1-NH2 was used as the host material to store cargoes of guest molecules, followed by
modification of carboxylatopillar arene (CP5) as a dual stimuli-responsive gatekeeper linked by
positively-charged pyridinium (Py) stalks (CP5-capped UMCM- 1-NH–Py). In acidic tumor tissues
or tumor cells, the gatekeeper of CP5 tended to be neutral, which weakened the noncovalent
binding interactions between CP5 and the stalk, leading to unblocking of the MOF followed by
the release of cargo. Upon addition of a competitive binding agent (methylviologen salts), which
possess a higher binding affinity to CP5 than Py, CP5 was detached from the stalks, which caused
the release of cargo. We integrated pH- and/or competitive binding agent-responsive strategies
into a single drug nanocarrier , where the CP5-capped drug nanocarrier showed high
encapsulation efficiency, negligible premature release, negligible cytotoxicity, desirable
biodegradability, and biocompatibility.
2/19/2019
METAL–ORGANIC FRAMEWORK (MOF)-BASED DRUG/CARGO
DELIVERY AND CANCER THERAPY
MING-XUE WU AND YING-WEI YANG*
29
31. developed a triply-responsive theranostic hybrid platform based on CP5-gated Zr-MOFs.
Positively charged quaternary ammonium salt stalks were tethered on UiO-66-NH2 via post-
synthetic modification, and then negatively charged CP5 was encircled on the stalks sitting on
the surface of the MOF through host–guest complexation. Controlled release experiments
verified that the prepared therapeutic platform was promising for potential bone regeneration
and bone cancer therapy because lower pH and higher concentration of Ca2+ in osteoclasts and
tumor cells could stimulate the release of the therapeutic agents via pH-responsiveness and
Ca2+-competitive responsiveness. Furthermore, high temperatures could damage and kill cancer
cells as well as weaken host–guest interactions to prompt gradually release of the therapeutic
molecule (5-Fu). Furthermore, the triply-responsive drug nanocarrier possessed desirable
properties, including negligible premature release, non-cytotoxicity, and good biocompatibility.
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Triply-responsive theranostic