13939
In the absence of added salt , alternating adsorption of 5 bilayers of protonated poly ( allylamine ) ( PAH ) and comb - like poly ( 2 - hydroxyethyl methacrylate ) - graft - poly ( acrylic acid ) ( PHEMA - g - PAA ) leads to ~ 2 - fold thicker coatings than adsorption of PAH and linear PAA , and the difference in the thicknesses of the two coatings increases with the number of bilayers .
 Chemical: poly ( allylamine ); Chemical: PAH; Chemical: poly ( 2 - hydroxyethyl methacrylate ) - graft - poly ( acrylic acid ); Chemical: PHEMA - g - PAA; Chemical: PAH; Chemical: PAA
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: poly ( allylamine ); Chemical: PAH; Chemical: poly ( 2 - hydroxyethyl methacrylate ) - graft - poly ( acrylic acid ); Chemical: PHEMA - g - PAA; Chemical: PAH; Chemical: PAA