text: The lipophilic group is typically a large hydrocarbon moiety, such as a long chain of the form CH(CH), with n > 4.
  The hydrophilic group falls into one of the following categories:
  # charged groups
  #* anionic. Examples, with the lipophilic part of the molecule represented by R, are:
  #** carboxylates: RCO
  #** sulfates: RSO
  #** sulfonates: RSO
  #** phosphates (the charged functional group in phospholipids)
  #* cationic. Examples:
  #** ammoniums: RNH
  # polar, uncharged groups. Examples are alcohols with large R groups, such as diacyl glycerol (DAG), and oligo ethylene glycol with long alkyl chains.
  Often, amphiphilic species have several lipophilic parts, several hydrophilic parts, or several of both. Proteins and some block copolymers are such examples.
  Amphiphilic compounds have lipophilic (typically hydrocarbon) structures and hydrophilic polar functional groups (either ionic or uncharged).
  As a result of having both lipophilic and hydrophilic portions, some amphiphilic compounds may dissolve in water and to some extent in non-polar organic solvents.
  When placed in an immiscible biphasic system consisting of aqueous and organic solvents, the amphiphilic compound will partition the two phases. The extent of the hydrophobic and hydrophilic portions determines the extent of partitioning.