N n 0 methylenebis acrylamide bis

All chemicals were obtained from commercial sources and used as received if not otherwise stated. N,N 0 -Methylenebis(acrylamide) (BIS; 99%, Sigma-Aldrich), ethanol (99.9%, Sigma-Aldrich), ammonium persulfate (APS; 98% Sigma-Aldrich), tetraethyl orthosilicate (TEOS; 98%, Sigma-Aldrich), hexane (Z99%, Sigma-Aldrich), ammonium hydroxide solution (28-30% NH 3 basis, Sigma-Aldrich) and (3-(trimethoxysilyl)propyl methacrylate) (MPS; 98%, Sigma-Aldrich) were used as received. N-Isopropylacrylamide (NiPAm; 97%, Sigma-Aldrich) was purified by recrystallization from hexane (95%, Sigma-Aldrich). Water was double deionized using a Milli-Q system (18.2 MO cm, Elga PURELAB Flex).

Materials N-isopropylacrylamide (NIPAm) was purchased from TCI (Portland, Oregon) and puried by recrystallization from hexanes (ACS reagent grade, EMD, Gibbstown, NJ) prior to use. N,N 0 -Methylenebisacrylamide (BIS) (99%), acrylic acid (AAc) (99%), and ammonium persulfate (APS) (98+%) were obtained from Sigma-Aldrich (St. Louis, MO) and were used as received. Tris (4-(dimethylamino)phenyl)methylium chloride (Crystal Violet, CV) and tetraethyl orthosilicate (TEOS, 98%) were obtained from Sigma-Aldrich (St. Louis, MO). Sodium chloride was obtained from EMD (Millipore, Billerica, MA), and deionized (DI) water with a resistivity of 18.2 MU cm was used. Cr/Au annealing was done in a Thermolyne muffle furnace from ThermoFisher Scientic (Ottawa, Ontario). Anhydrous ethanol was obtained from Commercial Alcohols (Brampton, Ontario). Sodium hydroxide (NaOH, 99.8%) and hydrochloric acid were purchased from Caledon Chemicals (Georgetown, Ontario) and were used as received. Fisher's nest glass coverslips were 25 Â 25 mm and obtained from Fisher Scientic (Ottawa, Ontario). Cr was 99.999% and obtained from ESPI as akes (Ashland, OR), while Au was 99.99% and obtained from MRCS Canada (Edmonton, AB).

N-Isopropylacrylamide (499%) (NIPAM), N,N 0 -methylene-bisacrylamide (BIS) (499.5%) and 2,2 0 -azobis(2-methyl-propionamidine)dihydrochloride (97%) (AAPH) were purchased from Sigma-Aldrich (Munich, Germany). All chemicals were used as received. A Millipore Milli-Q Plus 185 purification system was used for water purification.
Methanol (anhydrous) was purchased from Sigma-Aldrich Chemie GmbH, Germany. HYDRANAL TM -Composite 5 (Honeywell Fluka TM ) was purchased from Fisher Scientific GmbH, Germany. All chemicals were used without further purification.
PNIPAM microgel particles crosslinked with BIS were synthesized via surfactant-free precipitation polymerization as described in our previous work. 19 For neutron experiments 0.192 g of dried microgels were mounted in aluminium sandwich cells (Fig. 1). To measure the humidified sample 0.09 g of purified water (Millipore) has been added in small drops to the dried system. The degree of humidification is still too small to dissolve the microgels, it remains a gel like solid.