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Nanomaterials

Adrianna Bialecka Nanochemistry University Englisch 192 Karten

Nanomaterials

Karten in diesem Stapel (192)

  1. 1Why nanostructured materials?-increased surface to volume ratio gives high surface binding capacity.. e.g. of therapeutics
    -Many atoms are close to the surface (free "dangling" bonds, spin canting, interaction with environment, etc.) gives higher reactivity than bulk e.g. nanoscale catalysts
    -Quantum confinement (effect on band gap and emission spectra)
    -Electronic energy spacing (relevant when larger than kBT)
    -Localisation of surface plasmons
    -Supermagnetism ..for magnetic NPs
    ALL THESE PROPERTIES ARE PARTICLE SIZE DEPENDENT AND SO CAN BE CONTROLLED
  2. 2What is the IUPAC definition of nanomaterials?nanomaterials have sizes less than 100 nm (1 nm = 10^-9 m) in at least one dimension
  3. 3What are the different nanomaterials definition sizes?What are the different nanomaterials definition sizes?
  4. 4How are nanomaterials classified by substance?1. Inorganic materials: (metal nanoparticles, metal oxides, quantum dots) gold nanoparticles, Fe3O4 magnetic nanoparticles, TiO2 semiconductors, CdS luminescent quantum dots. Widespread applications
    2. Carbon Materials: C60, nanotubes, nanoparticles, graphene, nanodiamonds, nanohorns, nano onions. Potential applications include improved films and coatings, stronger and lighter materials, and applications in electronics, sensing
    3. Organic materials: Micelles, liposomes, dendrimers (nanosized polymers built from branched units). Polymer particles
    4. Composites: (combination of nanoparticles with other nanoparticles or with larger, bulk-type materials). Applications as additives to auto parts to packaging materials to enhance mechanical, thermal, barrier, and flame-retardant properties
  5. 5How are nanomaterials classified by dimensionality?How are nanomaterials classified by dimensionality?
  6. 6What are 0-D nanomaterials?What are 0-D nanomaterials?
  7. 7What are 1-D nanomaterials?What are 1-D nanomaterials?
  8. 8What are 2-D nanomaterials?What are 2-D nanomaterials?
  9. 9What are the typical NP types (by material)?-metal NPs (Au, Ag, Pt, Pd, Fe)
    -metal oxides NPs (TiO2, ZnO, Fe3O4)
    -metal chalcogenides NPs (CdS, CdSe, PbTe)
    -metal phosphides, halides (Co2P, CsPbBr3)
    -polymers, graphene/amorphous carbon
  10. 10What are the typical functional types of NPs?-fluorescent (CdS, CdTe, CsPbBr3)
    -plasmonic (Au, Ag)
    -magnetic (gamme- Fe2O3, Fe3O4, epsilon-Co)
    -catalytic (Pt, Pd, RuO2)
    -upconverting (NaYF4: 20% Yb 3+, 2% Er 3+)
  11. 11example of why semiconductor quantum dots size needs to be tunedexample of why semiconductor quantum dots size needs to be tuned
  12. 12What assumptions are made about particles in questions?that they are monodisperse spheres
    -monodispere = same diameter
    -same spherical shape
  13. 13Which size NPs are more stable and why?Which size NPs are more stable and why?
  14. 14What can bind to surface area of NPs and why?As the surface area is high a large amount of ligands can be physically or chemically bound
  15. 15How to ligands stabilise particles in suspension?How to ligands stabilise particles in suspension?
  16. 16How do ligands exchange?-These ligands are usually provided during NP synthesis sometimes after synthesis they are exchanged
    e.g. to improve stability in a givne solvent or to add a function; a dye, a pH responsive polymer etc. etc.    How do ligands exchange?
  17. 17What are the roles of ligands during NP synthesis?During synthesis the presence of surface active ligands can
    -stabilise nuclei/control the growth rate
    -stabilise growing particles/ control the growth rate
    -control nanoparticle shape by preferential binding at particular facets.. it is even possible to tune crystal phase
  18. 18So what are ligands critical for?Critical for size control and achieving monodispersity
    -surface binding should be strong/ but exchange should be possible
    -ligand conc., specifically the [L]/[P] ratio is a key control parameter
  19. 19How does Thermogravimetric analysis (TCA) work?1. Thermogravimetric analysis (TGA);
    -dry the sample (requires c. 10 mgs dry)
    -weigh the sample
    -monitor weight loss while very gradually increasing the temp    How does Thermogravimetric analysis (TCA) work?
  20. 20What are the 4 ways of analysing NP suspensions to determine ligand and inorganic amounts/conc?1. Thermogravimetric analysis (TGA)
    2. In situ colourimetric techniques
    3. In situ chemical reactions
    4. Digestion and then quantitative analysis
  21. 21How do in situ colourimetric techniques?E.g. absorption, fluorescence ... if there is a chromophore, or fluorophore on the NP surface, or if the core emits
  22. 22How do in situ chemical reactions work?How do in situ chemical reactions work?
  23. 23What is the different response for primary amines and secondary amines to ninhydrin assay?What is the different response for primary amines and secondary amines to ninhydrin assay?
  24. 24How do digestions and quantitative analysis help analyse NP suspension?-v low pH will dissolve most metallic or metal oxide NPs
    -v high pH will dissolve SiO2 NPs
    -Then determine the core conc ([Au], [Si], [Fe] etc) by flame atomic absorption and the ligand [ligand] by HPLC, NMR etc.    How do digestions and quantitative analysis help analyse NP suspension?
  25. 25What are the advantages and disadvantages of Thermogravimetric analysis (TGA)?Advantages -> works for most ligand types
    Disadvantages -> ligands must decompose at a different temp to the core, moderate precision, destructive, expensive instrument
  26. 26What are the advantages and disadvantages of in situ colourimetric techniques e.g. absorption, fluorescence?Advantages -> cheap, fast, sensitive, non-destructive
    Disadvantages -> not all ligands suitable. Are abs/em unchanged on binding, or size dependent?
  27. 27What are the advantages and disadvantages of in situ chemical reactions e.g. ninhydrin assay for free amines?Advantages -> specific, very bright ... so sensitive
    Disadvantages -> need a pendant amine, destructive
  28. 28What are the advantages and disadvantages of digestion and then analysis?Advantages -> precise/accurate .... the best way in most case
    Disadvantages -> expensive, time consuming, significant quantities needed, destructive, how to determine core composition (e.g. Ru vs Ru@RuO2)? How to get [Ligand]?
  29. 29How are NPs prepared (in solution)?Precursor -> Monomer -> Particle Nucleation -> Particle Growth
  30. 30How is monodispersity achieved?How is monodispersity achieved?
  31. 31What are the different levels of saturation?What are the different levels of saturation?
  32. 32How is size of NP controlled while maintaining monodispersity?Form fewer nuclei and it is possible to extend the growth phase but longer growth faces decreases monodispersity
  33. 33What is the mechanism of NP growth?Two stages; burst nucleation and diffusion controlled growth
    -Burst initiated by a critical level of supersaturation of precursor materials, or monomer, in the reaction mixture
    -Leading to a short period of (homogenous) nucleation from the suspension, as opposed to adding seeds
    -Leaving enough dissolved precursor to allow diffusion controlled growth
    -The phase of nucleation should be ideally separated from the growth phase and be short so that ongoing nucleation is suppressed and the existing nuclei grow uniformly
  34. 34How does solvothermal nanoparticle synthesis work and what are the two types?How does solvothermal nanoparticle synthesis work and what are the two types?
  35. 35What other paramaters affect nucleations and growth of NP in subtle ways?-solvent, precursors, aging time, temp and heating ramp, all affect nucleation and growth in subtle ways. In particular expts showed the two stages are not always fully separated, but monodispersity could sometimes still be achieved
  36. 36What are the three phases of NP growth, largely separated in time?1. Monomer formation
    2. Burst nucleation
    3. Growth, with diffusion-limited and reaction-limited regimes
  37. 37What is a monomer?What is a monomer?
  38. 38What is a nucleus and therefore burst nucleation occur?What is a nucleus and therefore burst nucleation occur?
  39. 39What are the equations that describe burst nucleation?What are the equations that describe burst nucleation?
  40. 40Graph showing the rate of formation of nucleiGraph showing the rate of formation of nuclei
  41. 41Why do molecules/ions precipitate to form nuclei?Why do molecules/ions precipitate to form nuclei?
  42. 42What are the criteria required for growth?What are the criteria required for growth?
  43. 43What does reaction limited mean in nanoparticle synthesis?The particles' growth is limited by the chemical reaction at the nanoparticle surface, rather than by getting reactants to the surface.
  44. 44What does diffusion-limited mean in nanoparticle synthesis?the chemical reaction itself is fast, but reactants cannot reach the nanoparticle surface quickly enough.
  45. 45How is size focusing possible by careful time of the addition of monomer during the growth phase?How is size focusing possible by careful time of the addition of monomer during the growth phase?
  46. 46What are the 4 steps involved in size-focusing by careful timing of the addition of monomer during the growth phase?i) Added particle
    ii) Monomer formed
    iii) S increase but less than supercritical saturation therefore no new nuclei formed
    iv) size focusing
  47. 47What is ostwald ripening?What is ostwald ripening?
  48. 48What are the two possible growth phases then?What are the two possible growth phases then?
  49. 49While many processes adhere to La Mer well, or quite well, there are "non La Mer" processes. What are they and how do we know about them?i) There are many NP synthesis where M is above Sc late into the process, but these still product monodisperse suspensions
    >nucleation must be ongoing
    >size focusing must be extensive and ongoing
    e.g. SiO2 NPs prepared using the Stober Method
    ii) There are many NP syntheses where growth is not (or not only) by addition of M to NPs, but rather NPs coalesce and merge
    e.g. Au NPs when prepared using some precursors
    *We know all this most often by sampling aliquots and running TEMs, sometimes with in situ monitoring (during rxn)*
  50. 50How would you increase NP size?i) Make fewer nuclei -> more material available per particles -> larger particle i.e. decrease the effective nucleation rate
    ii) Extend effective growth rate once nuclei formed, you want more material added to each nucleus. More growth -> larger particles
  51. 51How does ligand amount, present during particle synthesis affect NPs syntheses?How does ligand amount, present during particle synthesis affect NPs syntheses?
  52. 52What are the paramters that matter if you want to control NP size?What are the paramters that matter if you want to control NP size?
  53. 53What are the approaches to NP synthesisBottom-up colloidal (liquid phase) methods include: ……we will focus on these
    ….by reaction type (i.e. for formation of M)
    • Reduction / oxidation
    • Precipitation
    • Hydrolysis
    • Decomposition
    …...by process
    • Solvo / hydrothermal (thermal decomposition)
    • Sol-gel
    • Micro-emulsion and other structured media
    Gas phase bottom-up methods include :
    • Spray pyrolysis (gas phase)
    • Chemical vapour deposition
    Top-down methods include :
    • Milling
  54. 54What are some less common methods of NP synthesis?What are some less common methods of NP synthesis?
  55. 55How is Solvothermal nanoparticle synthesis better in flow than batch?Flow approach:
    -Vastly improved mixing
    -Almost no heat gradients
    -Residence times fixed (all good for monodispersity)
    -Continuous production (scale-up)
    -Complex setup (expensive/expertise/time)
    -Particles can clog lines
  56. 56Example of the route to synthesis of magentic Fe3O4 NPs by thermal decompositionExample of the route to synthesis of magentic Fe3O4 NPs by thermal decomposition
  57. 57What is the Fe(acac)3 route for Fe3O4 NP synthesis?What is the Fe(acac)3 route for Fe3O4 NP synthesis?
  58. 58If the reagent is Fe (acac)3 and the product is Fe3O4 1. Is there any redox? 2. If so what is the redox agent?If the reagent is Fe (acac)3 and the product is Fe3O4 1. Is there any redox? 2. If so what is the redox agent?
  59. 59What is the Fe(oleate) route for Fe3O4 NP synthesis?What is the Fe(oleate) route for Fe3O4 NP synthesis?
  60. 60In the Fe(oleate) route for Fe3O4 NP synthesis does [ligand] increase suppress knuc and/or kgrow?In the Fe(oleate) route for Fe3O4 NP synthesis does [ligand] increase suppress knuc and/or kgrow?
  61. 61Comparing the Fe(oleate) route to Fe( acac)3 ?Comparing the Fe(oleate) route to Fe( acac)3 ?
  62. 62What was the first approach to Au NP synthesis?What was the first approach to Au NP synthesis?
  63. 63What was the second approach to Au NP synthesis?What was the second approach to Au NP synthesis?
  64. 64What is the role of citrate?a) a reductant
    b) a capping agent (providing stabilising negative surface charge)    What is the role of citrate?
  65. 65What is the refined 4-step NP growth mechanism of the Turkevich approach?What is the refined 4-step NP growth mechanism of the Turkevich approach?
  66. 66What was the third approach to Au NP synthesis?What was the third approach to Au NP synthesis?
  67. 67What is the two phase synthesis in Brust-Schiffrin approach to Au NP synthesis?What is the two phase synthesis in Brust-Schiffrin approach to Au NP synthesis?
  68. 68What are the other uses of Brust-Schiffrin?What are the other uses of Brust-Schiffrin?
  69. 69What is the ligand increase effect in Brust-Schiffrin approach?What is the ligand increase effect in Brust-Schiffrin approach?
  70. 70What is the stober process for NP synthesis?What is the stober process for NP synthesis?
  71. 71What are the advantages and disadvantages of the stober process?What are the advantages and disadvantages of the stober process?
  72. 72example of NP synthesis in literature using stober processexample of NP synthesis in literature using stober process
  73. 73What is the mechanism in NP synthesis using stober process?What is the mechanism in NP synthesis using stober process?
  74. 74How is mesoporous silica made?How is mesoporous silica made?
  75. 75Magnetic NP clinical applications examplesMagnetic NP clinical applications examples
  76. 76What do the different colours on MRI contrast map show?What do the different colours on MRI contrast map show?
  77. 77Why is there a contrast in different parts of the brain despite the brain being usually little fat and water content unchanged?Why is there a contrast in different parts of the brain despite the brain being usually little fat and water content unchanged?
  78. 78What kind of MRI contrast reduce T1 spin-lattice show?What kind of MRI contrast reduce T1 spin-lattice show?
  79. 79How do MRI contrast agents reduce T1 and therefore enhance brightness?How do MRI contrast agents reduce T1 and therefore enhance brightness?
  80. 80An example of how MNP assembly can lead to a negative contrastAn example of how MNP assembly can lead to a negative contrast
  81. 81What happens to T2 when reduced?What happens to T2 when reduced?
  82. 82Which is preferred -superparamagentism or ferromagentism as MRI contrast?Which is preferred -superparamagentism or ferromagentism as MRI contrast?
  83. 83How can magnetic properties of NP be size dependent?How can magnetic properties of NP be size dependent?
  84. 84How can magnetic properties of NP be temperature dependent?How can magnetic properties of NP be temperature dependent?
  85. 85An example of a Clinical MRI agent T1 (positive constrast)An example of a Clinical MRI agent T1 (positive constrast)
  86. 86An example of a Clinical MRI agent T2 (negative constrast)An example of a Clinical MRI agent T2 (negative constrast)
  87. 87How does magentic nanoparticle hyperthermia work?How does magentic nanoparticle hyperthermia work?
  88. 88Example of AC-field hyperthermia for nanocubes and nanoflowersExample of AC-field hyperthermia for nanocubes and nanoflowers
  89. 89Example of using hyperthermia induced drug deliveryExample of using hyperthermia induced drug delivery
  90. 90What is dynamic light scattering (DLS or PCS)?What is dynamic light scattering (DLS or PCS)?
  91. 91What does measured dhyd depend on?What does measured dhyd depend on?
  92. 92What is the diffusion coefficient?What is the diffusion coefficient?
  93. 93What is Brownian motion?What is Brownian motion?
  94. 94What is the DLS sizing range?What is the DLS sizing range?
  95. 95What is light scattering?What is light scattering?
  96. 96What does the DLS instrument look like?What does the DLS instrument look like?
  97. 97What are the two different ways light can be scattered?What are the two different ways light can be scattered?
  98. 98What do the changes in light tell you?What do the changes in light tell you?
  99. 99What is the timescale of the fluctuations related to?What is the timescale of the fluctuations related to?
  100. 100What is used to monitor the light intensity fluctuations?What is used to monitor the light intensity fluctuations?
  101. 101example of plot the correlogram givesexample of plot the correlogram gives
  102. 102What are correlation functions used for?What are correlation functions used for?
  103. 103Example of how this correlation function is used to get DhydExample of how this correlation function is used to get Dhyd
  104. 104How is decay rate directly related to the diffusion coefficient (Dt)?How is decay rate directly related to the diffusion coefficient (Dt)?
  105. 105How does Stokes-Einstein Equation related Dt to dhyd?How does Stokes-Einstein Equation related Dt to dhyd?
  106. 106What are the units of stokes-einstein equation?What are the units of stokes-einstein equation?
  107. 107What is Fick's Law of diffusion?What is Fick's Law of diffusion?
  108. 108What are the two different methods to analyse DLS?What are the two different methods to analyse DLS?
  109. 109To get Z-ave and PDI what must the correlogram be fitted using?To get Z-ave and PDI what must the correlogram be fitted using?
  110. 110What is Polydispersity Index?What is Polydispersity Index?
  111. 111Example of more complex size distributions?Example of more complex size distributions?
  112. 112Example of a complex size distribution of a sample with two different sized particlesExample of a complex size distribution of a sample with two different sized particles
  113. 113How do you deal with different shapes of particles other than sphere?How do you deal with different shapes of particles other than sphere?
  114. 114What are the advantages of DLS sample preparation?In suspension, so no major preparation
    Non-destructive
    Need to watch – particle concentration, salt concentration, pH,
    temperature, aggregation – all affect how light scatters and
    particles move (see later)
    Simple instrument to use
    Sample volumes are small, down to just a 100 L
    Wide size range ~ 0.1nm to ~ 10µm
    Good for life sciences – e.g. aggregation of proteins
    Relatively low cost instruments
  115. 115What is the Zeta potential?What is the Zeta potential?
  116. 116What if particles do not repel sufficiently?What if particles do not repel sufficiently?
  117. 117What are the 3 models proposed for NP surface charge?What are the 3 models proposed for NP surface charge?
  118. 118What is the potential of the double layers surface charge?What is the potential of the double layers surface charge?
  119. 119Schematic view of NP surface charge double layerSchematic view of NP surface charge double layer
  120. 120What does the diffuse layer in the accepated Stern model?What does the diffuse layer in the accepated Stern model?
  121. 121What is the Debye Length and ionic streth of NP surface charge?What is the Debye Length and ionic streth of NP surface charge?
  122. 122What is the zeta potential for NPs?What is the zeta potential for NPs?
  123. 123What is the effect of pH on zeta potential?What is the effect of pH on zeta potential?
  124. 124How do we measure zeta potential?How do we measure zeta potential?
  125. 125What is Henry Equation?What is Henry Equation?
  126. 126What are the electrokinetic effects on NPs?What are the electrokinetic effects on NPs?
  127. 127How is electorphoretic light scattering measurement done?How is electorphoretic light scattering measurement done?
  128. 128What are the practical considerations for sample preparation (size and zeta)?What are the practical considerations for sample preparation (size and zeta)?
  129. 129Examples of different applications of colloidal dispersions and why Zeta potential must be routinely controlled to ensure stabilityZeta potential is routinely controlled to ensure stability
    1. The preparation of colloidal dispersions for useful purposes as in paints, inks,
    pharmaceutical and cosmetic preparations, food products, drilling muds, dyestuffs,
    foams and agricultural chemicals.
    2. The use of colloidal dispersions as a step in the manufacturing processes, for
    example in ceramic casting, cements and plaster, brickmaking and pottery, paper
    coatings and catalyst supports.
    3. The utilisation of colloidal phenomena including; detergency, capillary phenomena
    which are important in the wetting of powders, the expulsion of oil from reservoir rock,
    the retention of moisture and nutrients in soil, and in the coating of surfaces, the
    flotation of minerals, the absorption of impurities as in sugar refining, solvents recovery
    and electrophoretic deposition of paints.
    4. The destruction of unwanted colloidal dispersions in water purification, the fining of
    wines and beers, sewage disposal, the breaking of oil emulsions, the dewatering of
    sludges and the dispersal of aerosols and fogs.
  130. 130How to identify the surface functional groups of NPs?How to identify the surface functional groups of NPs?
  131. 131How is IR/Raman used for surface function group characterisation?How is IR/Raman used for surface function group characterisation?
  132. 132What are the characteristic IR peaks?What are the characteristic IR peaks?
  133. 133Example of functionalising nanoparticles in suspensionExample of functionalising nanoparticles in suspension
  134. 134How to prove succinic is bound to NPs?How to prove succinic is bound to NPs?
  135. 135How to prove the PEG is bound to the NPs?How to prove the PEG is bound to the NPs?
  136. 136What other chemical analysis methdos can be used to see if surface functional group have been attached to NP?What other chemical analysis methdos can be used to see if surface functional group have been attached to NP?
  137. 137Why is NP purification necessary?Why is NP purification necessary?
  138. 138What strategies can be used to separate NPs from low mw wt species?What strategies can be used to separate NPs from low mw wt species?
  139. 139How can centrifugation be used to separate NPs using their density?How can centrifugation be used to separate NPs using their density?
  140. 140What are the three main forces at play when particles in suspension undergo centrifugation?What are the three main forces at play when particles in suspension undergo centrifugation?
  141. 141What are the equations for each of the 3 forces in play in centrifugation?What are the equations for each of the 3 forces in play in centrifugation?
  142. 142How is the velocity at which particles will sediment at?How is the velocity at which particles will sediment at?
  143. 143How do you distinguish between Centrifuge rotor speed and relative centrifugal force?How do you distinguish between Centrifuge rotor speed and relative centrifugal force?
  144. 144Typical centrifuge instrumentsTypical centrifuge instruments
  145. 145Example of centrifugation as purification method for antibody conjugated NPs?Example of centrifugation as purification method for antibody conjugated NPs?
  146. 146What is the sedimentation coefficient?What is the sedimentation coefficient?
  147. 147What causes Sedimentation coefficient to increase?What causes Sedimentation coefficient to increase?
  148. 148How can NPs be separated by shape?How can NPs be separated by shape?
  149. 149How can suspensions of nanoparticles of different sizes be separated using Rate-Zonal Centrifugation?How can suspensions of nanoparticles of different sizes be separated using Rate-Zonal Centrifugation?
  150. 150How can suspensions of nanoparticles of different sizes be separated using Isopycnic Centrifugation?How can suspensions of nanoparticles of different sizes be separated using Isopycnic Centrifugation?
  151. 151Example of density gradient centrifugationExample of density gradient centrifugation
  152. 152How does size exclusion chromatography (SEC) work?How does size exclusion chromatography (SEC) work?
  153. 153How can Dialysis be done to separate NPs?How can Dialysis be done to separate NPs?
  154. 154How does size-selective precipitation from Aliquots to Harvest Monodisperse NPs?How does size-selective precipitation from Aliquots to Harvest Monodisperse NPs?
  155. 155What influences choosing a method of purification?1) What’s available within the group / company
    2) Remember most methods/ models are optimised for spherical particles – will need to be further optimised for particles of a different shape
    3) Depends on your need– are you trying to separate molecules from 100
    nm particles, or 10 nm from 15 nm particles?
    4) You need to watch for aggregation too – this will affect efficiency of all
    techniques
    5) Can get excellent “resolution” with size exclusion chromatography
    used to separate gold nanoparticles differing in size by only 6 Å;
    separation under magnetic field have been used resolve a mixture of
    4, 6, 9, 12, and 20 nm NPs.
  156. 156What are clean rooms in industry?What are clean rooms in industry?
  157. 157What is a colloid and how does it differ from an emulsion?What is a colloid and how does it differ from an emulsion?
  158. 158What are the key research challenges/objectives with NPs stability?What are the key research challenges/objectives with NPs stability?
  159. 159How to prevent, or control aggregation?How to prevent, or control aggregation?
  160. 160Example of graph showing NPs how the would interact according to the equations that would apply on macroscalesExample of graph showing NPs how the would interact according to the equations that would apply on macroscales
  161. 161What are the possible interparticles interactions of NPs?What are the possible interparticles interactions of NPs?
  162. 162In DLVO theory what are the two NP-NP interactions they assume?In DLVO theory what are the two NP-NP interactions they assume?
  163. 163What are the two wells in the Meta-Stable case?What are the two wells in the Meta-Stable case?
  164. 164What are the main NP-NP interactions?What are the main NP-NP interactions?
  165. 165What causes electrostatic interactions to occur in water?What causes electrostatic interactions to occur in water?
  166. 166Diagrams showing electrostatic interactions and debye lengthDiagrams showing electrostatic interactions and debye length
  167. 167How are debye length and ionic strength of NPs related?How are debye length and ionic strength of NPs related?
  168. 168What is the effect of pH on zeta potential?What is the effect of pH on zeta potential?
  169. 169Why do van der waal interactions arise?Why do van der waal interactions arise?
  170. 170What causes magnetic interactions between NPs?What causes magnetic interactions between NPs?
  171. 171How do solvent dependent interactions occur?How do solvent dependent interactions occur?
  172. 172How can entropy be used to determine aggregation spontaneity in solvent dependent interactions?How can entropy be used to determine aggregation spontaneity in solvent dependent interactions?
  173. 173What is Depletion interaction vs osmotic interaction?What is Depletion interaction vs osmotic interaction?
  174. 174How do NPs have steric (elastic) interactions?How do NPs have steric (elastic) interactions?
  175. 175How can total interaction potential be calculated?How can total interaction potential be calculated?
  176. 176Example of effect of NP size of the interaction potential for NPsExample of effect of NP size of the interaction potential for NPs
  177. 177The special case of PEGylation for bio-apps: NPs surface grafted with PEG have biomedical applicationsThe special case of PEGylation for bio-apps: NPs surface grafted with PEG have biomedical applications
  178. 178—
  179. 179—
  180. 180What are the approaches to Nanoparticle assembly (i.e. cluster formation)?What are the approaches to Nanoparticle assembly (i.e. cluster formation)?
  181. 181Are there other general colloidal routes to monodisperse nanoparticle clusters (NPCs)?Are there other general colloidal routes to monodisperse nanoparticle clusters (NPCs)?
  182. 182How are monodisperse NPCs made?How are monodisperse NPCs made?
  183. 183What do the reported approaches to monodisperse NPCs involve?What do the reported approaches to monodisperse NPCs involve?
  184. 184What are the current reported approaches to monodisperse NPCs?What are the current reported approaches to monodisperse NPCs?
  185. 185Example 1: Solvent/ligand interaction tuning approach to monodisperse NPCsExample 1: Solvent/ligand interaction tuning approach to monodisperse NPCs
  186. 186How can the internal organization of the NPs be controlled in Example 1: Solvent/ligand interaction tuning?How can the internal organization of the NPs be controlled in Example 1: Solvent/ligand interaction tuning?
  187. 187Example 2: Phase Collapse approach to monodisperse NPCsExample 2: Phase Collapse approach to monodisperse NPCs
  188. 188Example 3. Ligand desorption assembly by competitive stabiliser desorption (CSD) approach to monodisperse NPCsExample 3. Ligand desorption assembly by competitive stabiliser desorption (CSD) approach to monodisperse NPCs
  189. 189Example of graph showing ligand desorption assembly by competitive stabiliser desorption approach to monodisperse NPCs showing dhyd?Example of graph showing ligand desorption assembly by competitive stabiliser desorption approach to monodisperse NPCs showing dhyd?
  190. 190Graph showing how time affects PDI of monodisperse NPCs and how substrate is an ongoing requirement?Graph showing how time affects PDI of monodisperse NPCs and how substrate is an ongoing requirement?
  191. 191How are monodisperse NPCs assembled by gradual ongoing reduction in coverage, reducing repulse osmotic and steric interactions?How are monodisperse NPCs assembled by gradual ongoing reduction in coverage, reducing repulse osmotic and steric interactions?
  192. 192How does size of NP result in clusters being in primary or secondary well?How does size of NP result in clusters being in primary or secondary well?

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University Nanochemistry Karteikarten am Nanomaterials, erstellt von Adrianna Bialecka am 08/09/2026.
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