| 1 | r""" |
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| 2 | |
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| 3 | This model provides the form factor, $P(q)$, for a micelle with a ellipsoidal |
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| 4 | core and Gaussian polymer chains attached to the surface, thus may be applied |
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| 5 | to block copolymer micelles. To work well the Gaussian chains must be much smaller |
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| 6 | than the core, which is often not the case. Please study the reference carefully. |
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| 7 | |
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| 8 | Definition |
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| 9 | ---------- |
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| 10 | |
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| 11 | The 1D scattering intensity for this model is calculated according to |
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| 12 | the equations given by Pedersen (Pedersen, 2000). |
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| 13 | |
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| 14 | Validation |
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| 15 | ---------- |
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| 16 | |
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| 17 | This model has not yet been validated. Feb2015 |
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| 18 | |
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| 19 | |
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| 20 | References |
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| 21 | ---------- |
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| 22 | |
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| 23 | J Pedersen, *J. Appl. Cryst.*, 33 (2000) 637-640 |
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| 24 | |
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| 25 | """ |
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| 26 | |
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| 27 | from numpy import inf |
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| 28 | |
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| 29 | name = "polymer_micelle_ellipsoid" |
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| 30 | title = "Polymer micelle model" |
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| 31 | description = """ |
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| 32 | This model provides an approximate form factor, P(q), for a micelle with |
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| 33 | a ellipsoidal core with Gaussian polymer chains attached to the surface. |
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| 34 | """ |
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| 35 | category = "shape:sphere" |
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| 36 | |
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| 37 | # pylint: disable=bad-whitespace, line-too-long |
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| 38 | # ["name", "units", default, [lower, upper], "type","description"], |
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| 39 | parameters = [ |
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| 40 | ["ndensity", "1e15/cm^3", 8.94, [0.0, inf], "", "Number density of micelles"], |
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| 41 | ["v_core", "Ang^3", 62624.0, [0.0, inf], "", "Core volume "], |
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| 42 | ["v_corona", "Ang^3", 61940.0, [0.0, inf], "", "Corona volume"], |
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| 43 | ["sld_solvent", "1e-6/Ang^2", 6.4, [0.0, inf], "", "Solvent scattering length density"], |
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| 44 | ["sld_core", "1e-6/Ang^2", 0.34, [0.0, inf], "", "Core scattering length density"], |
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| 45 | ["sld_corona", "1e-6/Ang^2", 0.8, [0.0, inf], "", "Corona scattering length density"], |
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| 46 | ["radius_core", "Ang", 40.0, [0.0, inf], "", "Radius of core ( must be >> radius_gyr )"], |
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| 47 | ["radius_gyr", "Ang", 10.0, [0.0, inf], "", "Radius of gyration of chains in corona"], |
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| 48 | ["d_penetration", "", 1.0, [-inf, inf], "", "Factor to mimic non-penetration of Gaussian chains"], |
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| 49 | ["n_aggreg", "", 67.0, [-inf, inf], "", "Aggregation number of the micelle"], |
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| 50 | ["epsilon", "", 2.0, [-inf, inf], "", "Nonpenetration parameters"], |
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| 51 | ] |
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| 52 | # pylint: enable=bad-whitespace, line-too-long |
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| 53 | |
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| 54 | source = ["lib/sph_j1c.c", "micelles_ellipsoid.c"] |
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| 55 | |
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| 56 | demo = dict(scale=1, background=0, |
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| 57 | ndensity=8.94, |
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| 58 | v_core=62624.0, |
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| 59 | v_corona=61940.0, |
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| 60 | sld_solvent=6.4, |
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| 61 | sld_core=0.34, |
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| 62 | sld_corona=0.8, |
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| 63 | radius_core=40.0, |
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| 64 | radius_gyr=10.0, |
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| 65 | d_penetration=1.0, |
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| 66 | n_aggreg=67.0, |
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| 67 | epsilon =2.0) |
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| 68 | tests = [ |
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| 69 | # Match the test case for polymer_micelle |
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| 70 | # [{'epsilon':1.0, 'n_aggreg':6.0, 'radius_core':45., 'radius_gyr':20.}, |
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| 71 | # 0.01, 15.3532], |
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| 72 | ] |
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| 73 | # RKH 20Mar2016 - need to check whether the core & corona volumes are per monomer ??? and how aggregation number works! |
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| 74 | # renamed from micelle_ellipsoid_core to polymer_micelle, moved from shape-independent to ellipsoid section. |
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| 75 | # Ought to be able to add polydisp to core? And add ability to x by S(Q) ? |
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